"Pure Class A"

[frenchmon]

So what is "pure class A". Just about every "pure class A" amp is low in wattage and very expensive. How does a "pure class A" amp at 35 watts per channel compare to a non-pure class a amp at 200 watts per channel?

frenchmon

[Ajani]

So what is "pure class A". Just about every "pure class A" amp is low in wattage and very expensive. How does a "pure class A" amp at 35 watts per channel compare to a non-pure class a amp at 200 watts per channel?

frenchmon

The benefits are lower distortion (none of that switching distortion caused by typical Class AB amps) and allegedly sweeter sound (I've never tried one so I can't comment... Whereas a 200 watt class AB amp would give you greater dynamic range...

Trying to decide between a Musical Fidelity M6i and AMS35i???? (The price difference would be my deciding factor :ciappa: )

[frenchmon]

The benefits are lower distortion (none of that switching distortion caused by typical Class AB amps) and allegedly sweeter sound (I've never tried one so I can't comment... Whereas a 200 watt class AB amp would give you greater dynamic range...

Trying to decide between a Musical Fidelity M6i and AMS35i???? (The price difference would be my deciding factor :ciappa: )

Well the price over there is $6000 for the AMS35i. Don't know what it would be over here. Maybe to much for my pocket. The M6i is reachable.

Kinda scary Ajani...you reading my mind like that. Dont put no voodoo on me.

frenchmon

[Ajani]

Well the price over there is $6000 for the AMS35i. Don't know what it would be over here. Maybe to much for my pocket. The M6i is reachable.

Kinda scary Ajani...you reading my mind like that. Dont put no voodoo on me.

frenchmon

If I remember correctly the AMS35i is supposed to go for 9,000 USD (so triple the M6i)... though I'm not sure when it will reach the US, as last I know MF lost its American distributor (though it still has a few products available on AudioAdvisor)...

[mlsstl]

The easiest way to understand the difference between class A and AB is to picture a sine wave.

Half of the sine wave is above the mid-point and half below.

In a class B amp, the top half of the signal is amplified by one output device and the bottom half by the other. The two halves are joined together at the output to create the full sine wave.

Unfortunately, the point where the top and bottom halves are re-mated is somewhat imperfect so you get a notch or crossover distortion.

In a class AB amp the output devices are partially biased in the "on" state which helps reduce this distortion but does not eliminate it.

In a class A amp, the whole sine wave passes through one device so nothing has to be matched up at the output. This completely eliminates any notch distortion. (Note it doesn't reduce other types of distortion.)

The penalty is that the bias level has to be set very high which means the device is always "on" even when there is no signal. At best a class A amp is no more than 50% efficient (meaning 1 watt is wasted in heat for every watt delivered to a speaker.) Many are less efficient than this.

That is why class A amps tend to be lower power than AB. The heat generated and wasted energy are issues that need to be considered in the design. However, class A advocates are quite enthralled with the purity of the signal, particularly at lower volume levels where the notch distortion would be a higher percentage of the signal.

Higher output vs low-level signal purity is the trade off. Only you can make the call as to which you prefer.

[Geoffcin]

So what is "pure class A". Just about every "pure class A" amp is low in wattage and very expensive. How does a "pure class A" amp at 35 watts per channel compare to a non-pure class a amp at 200 watts per channel?

frenchmon

I think what your trying to ask is if class "A" power amp is somehow more powerful per watt than an A/B amp. A pure "Class A" is no more powerful per watt than a more common A/B amp. However it uses a lot more power as the circuit is always on.

Some of the more expensive high power amps from the likes of Pass Labs and such give you the best of both worlds with the first few dozen watts or so in pure class "A" before switching over to class A/B.

There's a good primer on "Class A" amps on the web;

http://www.electronics-tutorials.ws/amplifier/amp_5.html

Don't let the schematics bother you, the text is an easy read.

[E-Stat]

So what is "pure class A". Just about every "pure class A" amp is low in wattage and very expensive. How does a "pure class A" amp at 35 watts per channel compare to a non-pure class a amp at 200 watts per channel?
It is a qualitative difference. Perhaps a discussion by Nelson Pass would help. He has designed countless leading edge amplifiers for over thirty years and is the father of the sliding bias class A concept. Take a look here (http://www.passlabs.com/pass/437/leaving-class-a).

Virtually all preamps and other line level stages are class A for their better distortion characteristics - not lower levels per se, but the distribution with fewer high order products. Most amps today are of the AB design. Which means they act in class A for a portion of the range, then switch to class B at higher output levels. The point at which they transition is very different from amp to amp. Those with richer bias tend to be heavier and run hotter. I find that those with richer bias offer better low level resolution.

rw

[frenchmon]

If I remember correctly the AMS35i is supposed to go for 9,000 USD (so triple the M6i)... though I'm not sure when it will reach the US, as last I know MF lost its American distributor (though it still has a few products available on AudioAdvisor)...


Ouch...that hurt.

frenchmon

[Ajani]

Ouch...that hurt.

frenchmon

If you really want MF Class A... you could pick up a discontinued A1 (also 35 watts) for $1K... it's a cheap way to test one out... I've been tempted to get one, but I live in Jamaica, so the last thing I need is an amp to perform double duty as a room heater...

[blackraven]

My Parasound Halo A21 is an example of an AB amp that runs in Class A for the first 10wpc.
Its heat sinks are massive.

[frenchmon]

Thanks gents for the knowledge...and yes Geoffcin I was trying to ask about the power difference though I still did not understand how it worked but know I do. But as Ajani said, the pure A is just to expensive for my wallet. I'd get put out if I bought that thing home at triple the price of the M6i.


frenchmon

[blackraven]

If you want a high power Class A amp you need to buy this one- But get the fork lift ready!

http://www.lelong.com.my/Auc/List/2008-02DStd10975475.htm

[frenchmon]

My Parasound Halo A21 is an example of an AB amp that runs in Class A for the first 10wpc.
Its heat sinks are massive.

I've got a friend that has the Halo A21 and that thing is huge. Sounds good as well

Ajani I love Musical Fidelity's sound, and I really love my Xray, even better now that I got use to the way it looks. But the looks of those A1 products from MF just dont do anything for me. I know, I know....I should not be worried with looks, but man those things just don't do anything for me.

[frenchmon]

I'm concerned with good sound rather than another heater for my house. So does the pure class A mean better audible sound quality? And what makes class A so expensive?

frenchmon

[Ajani]

I've got a friend that has the Halo A21 and that thing is huge. Sounds good as well

Ajani I love Musical Fidelity's sound, and I really love my Xray, even better now that I got use to the way it looks. But the looks of those A1 products from MF just dont do anything for me. I know, I know....I should not be worried with looks, but man those things just don't do anything for me.

LOL... I can't even lie, if the heat wasn't an issue then the ugliness of the A1 would ruin it for me...

You could look into getting a matching X-T100 Amp (Wally at Underwood HiFi has one available for sale as part of a set with the XRay and power supply.. I suspect he'd be willing to sell you the amp by itself and sell the CD and power supply to someone else)...

I auditioned the set a few years ago (X-T100, XRay V8 and power supply) and sold my Rotel gear with the intention to upgrade to the MF set... (However, job changes and migrating killed that plan)...

[Geoffcin]

I'm concerned with good sound rather than another heater for my house. So does the pure class A mean better audible sound quality? And what makes class A so expensive?

frenchmon

Now that's the question!

Certainly the people who pay the premium for a pure class A amp would say so. As to why they cost more, that I cannot answer you definitively. For all intensive purposes they are constructed with the same components, with a class A amp actually needing LESS complex circuitry. Of course generating so much heat those components must be robust, and the designer has to provide generous heat sinks too, so there's an extra cost compared to an A/B amp.

[Feanor]

.... As to why they cost more, that I cannot answer you definitively. For all intensive purposes they are constructed with the same components, with a class A amp actually needing LESS complex circuitry. Of course generating so much heat those components must be robust, and the designer has to provide generous heat sinks too, so there's an extra cost compared to an A/B amp.
The power supplies of Class A amps must be much more robust for a given power output than Class A/B. I'd say that's the major reason they are more expensive.

[Feanor]

It is a qualitative difference. Perhaps a discussion by Nelson Pass would help. He has designed countless leading edge amplifiers for over thirty years and is the father of the sliding bias class A concept. Take a look here (http://www.passlabs.com/pass/437/leaving-class-a).

Virtually all preamps and other line level stages are class A for their better distortion characteristics - not lower levels per se, but the distribution with fewer high order products. Most amps today are of the AB design. Which means they act in class A for a portion of the range, then switch to class B at higher output levels. The point at which they transition is very different from amp to amp. Those with richer bias tend to be heavier and run hotter. I find that those with richer bias offer better low level resolution.

rw
Speaking of Pass Labs and Class A, I'm thinking I'd really covet a pair of XA200.A (http://www.passlabs.com/pass/254/xa2005)'s, (400 wpc @ 4 ohms), to power my Maggies.
:16:

http://www.passlabs.com/pass/wp-content/gallery/cache/87__600x400_xa200_5.jpg

A pair of these beasts is in the range of $35,000, weighs 360 lbs, and sucks 1400 watts at idle.

[Geoffcin]

Speaking of Pass Labs and Class A, I'm thinking I'd really covet a pair of XA200.A (http://www.passlabs.com/pass/254/xa2005)'s, (400 wpc @ 4 ohms), to power my Maggies.
:16:

http://www.passlabs.com/pass/wp-content/gallery/cache/87__600x400_xa200_5.jpg

A pair of these beasts is in the range of $35,000, weighs 360 lbs, and sucks 1400 watts at idle.

What, only a pair? How about a quad for bi-amping!.

[Mr Peabody]

Any one heard of these? http://www.jamnaudio.com/claytonaudio.html

Frenchmon, care to guess why they are called "Clayton" Audio? They are pretty expensive as well. Not like a Pass monoblock but several thousand. I heard a pair of the CA monoblocks drive the Dynaudio Sapphires and it was amazing.

That KSA would be a sweet amp.

[RGA]

Another factor on this topic involves negative feedback. Proponents like me prefer as little feedback or no negative feedback as possible. High Damping factor amplifiers (usually high power not Single Ended solid state amplifiers) tend to have more negative feedback and IMO that means worse sound. UHF magazine in their book does not recommend amplifiers with Damping factors over 40.

Power with reasonable high efficient speakers do not need more than about 8 watts to play loud with bass and treble and dynamics. Since there are no advantages of owning hard to drive speakers why spend more to get more power on worse sounding amplifiers? Not a lot of sense to me in that approach.

And as Martin Colloms noted in Stereophile - Against some of the top Solid State designers Colloms had those SS designers pit their amplifiers against eachother - Colloms put in a no negative feedback 10 year old used Tube amp - all the SS designers in a blind listening session chose the 10 year old tube amp for $100 over their $3k models. http://www.stereophile.com/reference/70/

[Smokey]

Power with reasonable high efficient speakers do not need more than about 8 watts to play loud with bass and treble and dynamics. Since there are no advantages of owning hard to drive speakers why spend more to get more power on worse sounding amplifiers? Not a lot of sense to me in that approach.


I think if you add distortion (THD) to the mix, you will get a different picture of what you stated.

As you said 8 watts of power will certainly get loud, but distortion will be high due to not having enough Dynamic Headroom to handle power spikes. This is where more power is welcome to keep [even&odd] distortion low.

In another word more power is not about quantity, but rather quality :)

[audio amateur]

I think if you add distortion (THD) to the mix, you will get a different picture of what you stated.

As you said 8 watts of power will certainly get loud, but distortion will be high due to not having enough Dynamic Headroom to handle power spikes. This is where more power is welcome to keep [even&odd] distortion low.

In another word more power is not about quantity, but rather quality :)
If your speakers are a little efficient & your not listening at ear bleeding levels, then there should be no need for more than 8 watts, even to handle dynamics peaks without distortion.

[Jim Eck]

http://dozin.com/godzilla/amp.htm#

The Godzilla Class A amplifier, check out the link, this is one very high powered Class A amplifier, they where used by Bob Weir and Phil Lesh of the Grateful Dead, an amplifier that can double as a welder! Unfortunately they only made 23.

Jim

[Geoffcin]

If your speakers are a little efficient & your not listening at ear bleeding levels, then there should be no need for more than 8 watts, even to handle dynamics peaks without distortion.

Well that leaves my speakers out as I've pushed every amp I've ever owned into clipping. (and I've had some brutes too) Really though, most modern amps have more than 8 watts, unless we're talking about S.E.T. amps and that's a discussion for another thread. (even though SET's are all Class "A" in design)

[Ajani]

Since there are no advantages of owning hard to drive speakers.....

You mean other than that the person might really love the sound of a particular set of hard to drive speakers?

If the speakers someone likes have high sensitivity, then certainly a low powered Class A amp should be a top consideration.... but if someone happens to really like the sound of an inefficient pair of speakers, then a big class AB Brute is probably going to be a better choice...

[Jim Eck]

You mean other than that the person might really love the sound of a particular set of hard to drive speakers?

If the speakers someone likes have high sensitivity, then certainly a low powered Class A amp should be a top consideration.... but if someone happens to really like the sound of an inefficient pair of speakers, then a big class AB Brute is probably going to be a better choice...

My Legacy Classics (these can be ran 4 ohm or using the crossover, split to 8 ohm via 2 amplifiers) are not inefficient but they do require power to do their best, I have ran them with less power but have found the more power they receive the better they sound. Currently I am running 2 250 WPC (8ohm) amplifiers to them, one driving the low end and the other driving the high end, I have yet to clip them, but give me time.:biggrin5:

Jim

[Geoffcin]

Since there are no advantages of owning hard to drive speakers.....

RGA, please refrain from off topic remarks like this.

[bobsticks]

Any one heard of these? http://www.jamnaudio.com/claytonaudio.html

Frenchmon, care to guess why they are called "Clayton" Audio? They are pretty expensive as well. Not like a Pass monoblock but several thousand. I heard a pair of the CA monoblocks drive the Dynaudio Sapphires and it was amazing.

I heard that exact setup the last time I was down about your way...and was, indeed, amazing...

[E-Stat]

Well that leaves my speakers out as I've pushed every amp I've ever owned into clipping.
Mine, too. ;)

rw

[mlsstl]

...care to guess why they are called "Clayton" Audio?

I just assumed it is because they are located in Clayton, MO, an upscale suburb of St. Louis.

[audio amateur]

Well that leaves my speakers out as I've pushed every amp I've ever owned into clipping. (and I've had some brutes too) Really though, most modern amps have more than 8 watts, unless we're talking about S.E.T. amps and that's a discussion for another thread. (even though SET's are all Class "A" in design)
Didn't you say you drove once your 3.6s with a Trends amp?

I believe anyone can push an amp into clipping on purpose, however doing so on normal program material at moderate listening levels (<80dB) is a different story.

[Feanor]

Mine, too. ;)

rw
You guys must listen awfully loud. I've never driven any amps to clipping with my Maggies, not even my 40 wpc NAD or my 30 wpc, circa 1972, Harmon Kardon receivers.

[Geoffcin]

Didn't you say you drove once your 3.6s with a Trends amp?

I believe anyone can push an amp into clipping on purpose, however doing so on normal program material at moderate listening levels (<80dB) is a different story.

Actually I drove mt 3.6's with a battery powered "T" amp on a lark. Don't get me wrong, I'm not saying that you NEED a super powerful amp in every case, but in MY case if you want to recreate the dynamics of a concert then yes, your going to need some watts.

[mlsstl]

...if you want to recreate the dynamics of a concert...

That may be true of live classical music, but it is pretty rare to have an extraordinary dynamic range on a recording.

Digital recordings have a very hard maximum limit. Analog clipping is a bit softer, but there is still a practical limit on LPs and tape. Once you're at 0 to 3 dB on the VU meter, there just isn't any practical headroom above that. (The exact point depends on the recording equipment and the calibration of the meters.)

I've transferred well over 2,000 LPs and tapes to digital for my music server, so I am very used to looking at the dynamic range on rock, jazz and classical records. For most records, it is very unusual to have an average recorded volume level that is much under 10 dB from the peaks on the record. Even in classical, you might see 20 or 30 dB down from the peaks, but remember the soft sections are exactly that. They should be played at low volume. If you are playing the playing the soft sections of Dukas' "The Sorcerer's Apprentice" at 90 dB, you are way off the mark in terms of what you'd hear live at the symphony.

Keep in mind that even on orchestral classical music, the microphones are far closer to the orchestra than anyone in the audience would be at a live event. And, very few classical recordings are made these days that don't also include highlight mikes. I noted the other day that the Emerson Quartet used 14 mikes to record their version of Mendelssohn's "Complete String Quartets." That's for four string instruments!

This idea that you can be cranking along, listening at 90 or 95 dB and need the headroom for a 30 or 40 dB peak is a situation that simply does not exist on any recording I've ever seen. And that is without even considering the current crop of recordings that have fallen prey to the loudness wars.

[E-Stat]

You guys must listen awfully loud. I've never driven any amps to clipping with my Maggies, not even my 40 wpc NAD or my 30 wpc, circa 1972, Harmon Kardon receivers.
The big Sound Labs require lots of power, especially when there is serious bass content. 600 tube watts gets me peak levels no higher than about 90 db at my listening distance. I'd really like to have double that for classical content.

The double Advents, however, will really rock out with the 400 watt '81 Threshold Stasis. At Halloween, I took the garage system (and preamp from main) to my neighbor's back yard for his daughter's party. There I could get higher levels of very clean output! As DJ, I wore my tux and Phantom of the Opera cape and mask. :)

System (http://home.cablelynx.com/~rhw/audio/halloween1.jpg)
View from "stage" (http://home.cablelynx.com/~rhw/audio/halloween2.jpg)

rw

[audio amateur]

System (http://home.cablelynx.com/~rhw/audio/halloween1.jpg)
View from "stage" (http://home.cablelynx.com/~rhw/audio/halloween2.jpg)

rw
I bet you were worried sick and incubated them during the whole evening :D

[E-Stat]

I bet you were worried sick and incubated them during the whole evening :D
Initially I was concerned about taking out a tweeter since I normally run them at comparatively low levels in the garage (like -20 db). Because this was attended by 13 to 15 year olds, I wasn't concerned about some drunk cranking the preamp. After four hours of running the amp wide open, however, the Advents survived the event. Ferro-fluid cooling works! At a distance of about twenty feet back, they sounded pretty awesome and totally devoid of the electronic grunge and hardness you get with most sound reinforcement gigs.

rw

[Ajani]

The big Sound Labs require lots of power, especially when there is serious bass content. 600 tube watts gets me peak levels no higher than about 90 db at my listening distance. I'd really like to have double that for classical content.

The double Advents, however, will really rock out with the 400 watt '81 Threshold Stasis. At Halloween, I took the garage system (and preamp from main) to my neighbor's back yard for his daughter's party. There I could get higher levels of very clean output! As DJ, I wore my tux and Phantom of the Opera cape and mask. :)

System (http://home.cablelynx.com/~rhw/audio/halloween1.jpg)
View from "stage" (http://home.cablelynx.com/~rhw/audio/halloween2.jpg)

rw

Judging from the chalk outlines on the ground, I'm guessing some of the kids tried to steal your equipment and you had to teach them a hard lesson...

[audio amateur]

It's nice that you could help out like that. I'm curious as to what tunes were played :)

Do you wire the Advents in parallel or in series?

[E-Stat]

Judging from the chalk outlines on the ground, I'm guessing some of the kids tried to steal your equipment and you had to teach them a hard lesson...
LOL! Actually, that "prop" was suggested by the Mom. I modeled for one of the outlines - which caused the daughter, her friend and brother to say "Do me next!"

rw

[E-Stat]

It's nice that you could help out like that. I'm curious as to what tunes were played :)
They were chosen by the thirteen year old girl and her Mom if that helps! It was a mix of classic Halloween stuff and a bunch of current teen pop stuff. One guy brought over a CD with "PT Cruiser". The neighbor who lives on the other side heard that and in jest wondered what it was. He used the "Shazam" app on his iPhone, found out and downloaded it. It really is a repetitious song with few lyrics beyond the title. He's really funny singing that song! I still have the ripped content, but with no titles. I just "Shazammed" a couple more:

"Skanky Legg" by the GS Boyz.
"Krazy" by Pitbull Feat. Lil' John
"Battlefield" by Jordin Sparks
"I'm a Flirt" by R. Kelly

Never heard any of these, but then I'm an old guy. :)


Do you wire the Advents in parallel or in series?Definitely parallel with separate runs to each speaker. They present a nominal 4 ohm load that drops to 2.3 ohms in a couple of places. Which is a piece of cake for an amp designed to drive Dayton-Wright electrostatics.

rw

[RGA]

I think if you add distortion (THD) to the mix, you will get a different picture of what you stated.

As you said 8 watts of power will certainly get loud, but distortion will be high due to not having enough Dynamic Headroom to handle power spikes. This is where more power is welcome to keep [even&odd] distortion low.

In another word more power is not about quantity, but rather quality :)

Actually that is true but you can get around that with speaker efficiency. And the type of distortion from tube amps is easier on the ears - while the SS sound is always present at every volume.

100db sensitive benign impedance load speaker and a 8 watt amp

1w = 100db (90db is considered loud and with prolonged use at 90db will cause hearing damage) - 1 watt is 1/10th the amplifiers output and is already giving you 10 db over what is consider Loud. 100db is very loud
2w = 103db
4w = 106db
8w = 109db (These are leave the room volume levels - and in fact 100db for most would be leave the room volume levels. Typical listening is in the sub 85db realms - so all dynamic swings are easily covered.

85db speakers with a 100 watt amplifier

85db - 1 w
88db - 2w
91db - 4w
94db 8 w
97db 16w
100db 32w
103db 64w
106db 128watt.
109db 256w (To get the same level (dynamic headroom included would require 256watts to get the same level dynamic headroom included as the system above. - but the question is how many speakers of 85-87bb ilk can truly take sustained 256watts - not a whole lot I can tell you that - most standmount varieties can handle 80-120 watts.

The first system will have more volume and more dynamics that system two.

Of course if one insists on using the 85db speaker then you have to have more power - the problem is for me that as good as some of the hard to drive speakers are - the foibles of the amplifier ruin everything for me. The best "sound quality" I have ever heard from the N801 was with a Wyatech 11 watt tube amp - but unfortunately you could not play it very loud. But put on a MF or Bryston and the sound was better in the off position.

This is the same with panels - I liked the Quads better the second time around with low watt tube amplifiers - and the 2905 has a flat impedance and the tube amp was never really put in distress. Brilliant sound.

At the very least - if you are running a conventional boxed speaker of low efficiency get a tube preamp SET stage on in there and maybe even a tube hybrid monoblock stage like the Shengya PM 150's. Or a pure class A Single ended solid state design like Pass Labs or the Sugden Masterclass series.

At least "try" them alongside the usual class A/B culprits.

[RGA]

You mean other than that the person might really love the sound of a particular set of hard to drive speakers?

If the speakers someone likes have high sensitivity, then certainly a low powered Class A amp should be a top consideration.... but if someone happens to really like the sound of an inefficient pair of speakers, then a big class AB Brute is probably going to be a better choice...

My speakers are 89.5db (92.5db in corners) and I run an 4-10 watt amp (4 without distortion). This is not exactly huge sensitivity so there are plenty of substitute speakers out there that can play real loud without dynamic compression on 8-10 watts.

I suppose I really amp in the front end matters most camp because it makes little sense to uses a garbage in to a speaker that can only use garbage in amplifiers. I think most people would want to keep their options open on the front end - with a HE speaker you can use ANY amplifier of any power rating. And in general HE speakers can also play a helluva lot louder than lower efficiency speakers - which is why rock concerts use horns not panels.

If one is truly serious about very loud Guns and Roses you go with something like the big K-Horn or Tannoy studio series double 15 inch woofer jobs that actually still sound good - certainly for this kind of music. You can run a 5 watt amp that will blow you out of the room - there are always high power class A very low feedback tube amps around.

Because honestly - a 300 watt SS amp on a set of 83db Totem's or pretty much any and all multiple stacked 6 inch woofer array playing AC/DC is a joke - no matter what amplifier power you have - the speaker can only take so much.

[RGA]

You guys must listen awfully loud. I've never driven any amps to clipping with my Maggies, not even my 40 wpc NAD or my 30 wpc, circa 1972, Harmon Kardon receivers.

Here's the thing - I was at a listening session a few years ago with Odyssey Stratus amps being run as monoblocks - I am guessing but something like 200 watts per channel running Gershman acoustic X-1 sub 1 and playing pretty darn loud - we measured the level ~75db. we could talk over the music but at elevated levels. This would not have used more than a watt of that system. Putting on a Class T amp of 5 watts and it was fine. It was better on the AN K power wise but the K is easier in the impedance department.

I seriously doubt owners sit at home and play 8 hours every day day in day out of deafening levels where you have to scream at the top of your lungs to the person beside you. If you do you lost your hearing years ago and quality doesn't matter.

Buy the quality SET amp for your 99% of usual listening levels and if you really want to impress your friends for the 5 minutes you can stomach extreme levels - buy a Crown for $100 but don't suffer the other 99% of the time listening to inferior sounding amplifiers just to have the odd ridiculous volume level session.

I mean I keep my Vanguards around for this very reason - If I want the 120db sessions - but those are so few and far between that the speakers are taking up space in a closet. Partly because the standmounts with 4 undistorted watts have already generated enough complaints and I have not even got it to half volume yet!

lastly you can always buy more powerful SE amplifiers for bigger rooms and lower impedance requests. Moreover when you finally have a superior sounding amplifier you don't feel the need to turn it up trying to get volume level to compensate for a lack of resolution.

[Geoffcin]

RGA makes it sound like all you need is a high efficiency speaker and you good to go, but that's simply not the case. MOST high efficiency speakers I've heard are really lacking in lower bass. The only one's that that make passible bass to my ears are huge, and they have to be based on of the basic speaker design principles worked out long ago by the "H" in "KLH" called "Hoffman's Iron Law"

Simply put, Hoffman's Iron Law states that the efficiency of a woofer system is directly proportional to its cabinet volume and the cube of its cutoff frequency.

So, there's no free lunch on efficiency even if you decide to use the room corners as quasi-horn loading.

Oh, and I have heard Totem Mani-2 Sig's playing Guns & Roses. They absolutely rocked out! (with a 400wpc amp no less!)

[E-Stat]

85db speakers with a 100 watt amplifier

85db - 1 w
88db - 2w
91db - 4w
94db 8 w
97db 16w
100db 32w
103db 64w
Remember how this was measured - typically at 1 meter and at an *easy" 1 kHz. As for me, I listen at a distance of about four meters - where the bass is most linear in my eight meter long room. Point source speakers drop 6 db for every doubling of distance, so that would be 12 db less for my position at 1 Khz and lower still in using real world wideband material (not AM radio).

rw

[Geoffcin]

This idea that you can be cranking along, listening at 90 or 95 dB and need the headroom for a 30 or 40 dB peak is a situation that simply does not exist on any recording I've ever seen. And that is without even considering the current crop of recordings that have fallen prey to the loudness wars.

Of course a 40dB peak is nearly unheard of on any program material I've listened to. Even with that being said, sometimes the numbers do add up to needing more power. Here's a clip from a review done a while back on the then new Magnepan MMG, the SMALLEST of the line;

http://www.soundstage.com/entry04.htm

"Let's put this into perspective for you. My Proton D1200 power amp has big, cool power meters on the front that are fairly accurate. I was routinely pumping over 50w/ch into these speakers in routine listening; no way would you want to have less than that and expect to play a set of MMGs at all. When I cranked things up, I could easily drop over 200w into each speaker. At one point, I was using an original Adcom GFA-555 to power the MMGs. For those not familiar with this amp, it's a solid state brute that is rated for 200w/ch of continuous power (even more into this 4 ohm load), and has good headroom to boot. There's two clipping lights on the front of the amp that brighten when you're pushing it too hard. In the five years I've owned this amp, I've seen those lights once, that was during some testing where I purposely beating up on a pair of speakers just to see what the limits where on the amplifier and the speakers were. Hook up these power hungry Magnepans to it, turn the volume up, and those lights start blinking like a Christmas tree. "

[RGA]

RGA makes it sound like all you need is a high efficiency speaker and you good to go, but that's simply not the case. MOST high efficiency speakers I've heard are really lacking in lower bass. The only one's that that make passible bass to my ears are huge, and they have to be based on of the basic speaker design principles worked out long ago by the "H" in "KLH" called "Hoffman's Iron Law"

Simply put, Hoffman's Iron Law states that the efficiency of a woofer system is directly proportional to its cabinet volume and the cube of its cutoff frequency.

So, there's no free lunch on efficiency even if you decide to use the room corners as quasi-horn loading.

Oh, and I have heard Totem Mani-2 Sig's playing Guns & Roses. They absolutely rocked out! (with a 400wpc amp no less!)

You are still limited by the maximum watt figure of the loudspeaker - I keep reading people with 400 watt amplifiers - the Mani-2 has a maximum of 200 watts but it also bottoms out at 110db. So Regardless of the amplifier used the limit of this 85db loudspeaker is

85db 1w
88db 2w
91db 4w
94db 8w
97db 16w
100db 32w
103db 64w
106db 128w
109db 256w

Which is ok - my system achieves the same volume level as the Mani-2 with considerably less watts without going over the max watt intake of the loudspeakers.


And when you get into "true" sub territory an amplified sub for sub 30hz down to sub 10hz the amplifier "sound" is not that important - it's when the amp sound or the sub for that matter is being used for the actual initial sounds of notes. To me subs are best for ambiance and feeling bass - not so much for audible spectrum sound. High efficiency generally has to be big to have bass but they also sound more dynamic than the likes of LE speakers - no matter how powerful the amps.

[RGA]

Remember how this was measured - typically at 1 meter and at an *easy" 1 kHz. As for me, I listen at a distance of about four meters - where the bass is most linear in my eight meter long room. Point source speakers drop 6 db for every doubling of distance, so that would be 12 db less for my position at 1 Khz and lower still in using real world wideband material (not AM radio).

rw

And all that means to me is that you want a higher efficiency speaker even more in a larger room to counteract the db drop at distance. It's still an apples to apples issue.

In a large room with low efficiency speakers - you are correct - SETs will be in real trouble. And bigger powerful ones costs a bomb.

But my contention is that I see no point in having a low efficient speaker and then putting a SS etchy high grain notch distortion ear fatiguing amplifier in the front. If the speaker is High resolution (few LE speakers are fortunately for them) then you will hear with even greater magnitude just how poor the amplifiers are on sound quality. Granted you have Pass Labs right? A SE pure class A no feedback design? You must have decided on it for reasons other than looks no?

Still the best actual sound I have heard with even tough to drive panels and conventional lower efficiency speakers is with SE amplifiers. Yes they are limited with volume capabilities but then why buy worse sounding high power amplifiers? Yes they can play loud but the sound is bad!! Why not keep the better front end and get a speaker that is easy to drive?

The bottom line is this - An AN E with a 10 watt amp in a medium room - 25 by 25 or smaller with Guns and Roses can play to leave the room volume levels to 25 -30hz flat in room at the listening chair. There are bigger high efficiency speakers like the Tannoy Westminster that can play louder deeper and are even easier to drive!! That will beat the snot out of any 1000 watt amp and any panel or any speaker in the size and weight class of the Wilson Sophia. And the Tannoy SET will give you all that oomph and ridiculous drive level and hit you in the chest impact - but it will also make Beethoven sound good. Something that no SE amps IMO just don't do even in the $70grand Krell Levinson systems sound merely average to worse than average. The Tannoy/SET will save huge cash - and save you piles of money. Granted the Westminster is butt ugly but....

[mlsstl]

I was routinely pumping over 50w/ch into these speakers in routine listening...

If a person is using 50 watts to generate his true average listening level, then yes, you'll need 500 watts in order to have 10 dB headroom.

However, I owned a set of Maggie 1.6QRs for several years and drove them very successfully with a pair of 60 watt Dyanco Mk IIIs (modded, but not for more power.) I had no problem reaching an average listening level of 85 or even 90 dB (quite loud for home listening for most people) and never felt the need for more power.

If I recall correctly, the 1.6 QRs were about 86 dB sensitivity, so 1 or 2 watts was giving me an average listening level. The rest of the 60 watts was available for the peaks.

Of course, there are some people who listen at incredibly high levels. I've known a few people like that in my day. As one might say, more power to them. ;-)

If someone is cranking a constant average of 50 watts into a pair of MMGs, I can only imagine what type of volume level they prefer for listening.

It is one thing for a rock band to hit 120 dB in a big arena, or a symphony orchestra to hit something over 100 dB at full tilt in a 1,000 seat concert hall when you're dozens or even hundreds of feet from the players, but I find nothing realistic or attractive with those levels in a home living room.

However, that's just me and there are certainly plenty of big amps out there for those who want them.

[E-Stat]

And all that means to me is that you want a higher efficiency speaker even more in a larger room to counteract the db drop at distance.
To each his own. My choice of speaker is not a particularly efficient one.


But my contention is that I see no point in having a low efficient speaker and then putting a SS etchy high grain notch distortion ear fatiguing amplifier in the front.
Agreed. Which is why I use relatively high powered tube monoblocks each fed by a 20 amp dedicated circuit.


Granted you have Pass Labs right? A SE pure class A no feedback design? You must have decided on it for reasons other than looks no?
I use a pair of VTL MB-450s to drive the Sound Labs. While I also own a Nelson Pass designed Threshold amp for the vintage system, what I really lust for is a pair of VTL Siegfrieds. They sound positively magnificent in HP's Scaena system. Especially using Odins. :)

http://home.cablelynx.com/~rhw/audio/siegfrieds.jpg


Still the best actual sound I have heard with even tough to drive panels and conventional lower efficiency speakers is with SE amplifiers.
While I listen at more moderate levels than many (typically in the 70 - 80 db range), a 10 watt SET would merely whisper with the U-1s.


There are bigger high efficiency speakers like the Tannoy Westminster that can play louder deeper and are even easier to drive!! That will beat the snot out of any 1000 watt amp and any panel or any speaker in the size and weight class of the Wilson Sophia.
Only if the utter coherence and purity of a single electrostatic driver is unimportant to you. :)

rw

[RGA]

Volume is a factor of the sensitivity of the speaker, the maximum watts the speaker can handle, and if provided the maximum decibel rating before compression, and impedance of the speaker, and the power supply quality of the amplifier (not quantity rating on the spec sheet).

Looking at a high power amplifier in isolation is a non issue.

If a typical speaker is 87db sensitive and an easy impedance and can take 120 watts then there is no point in buy an amplifier over 120 watts - Period - regardless of tube or SS.

1 w - 87db
2 w - 90db
4w - 93db
8w - 96db
16 w - 99db
32w - 102db
64w - 105db
128w - 108db
256w - 111db (This is the maximum level this speaker can play) You can talk about 3db drops at 2 meters all you want but that is still an apples to apples argument as all the other speakers will have the same issues). So you go out and buy your 256watt Bryston and you play to maximum you get 110db. (and then only in max peaks) Great. Whether you use 256watt amplifier or a 6million watt amplifier you are only ever getting ~110db.

And as E-Stat pointed out this level drops significantly at distance - more power won't help you though because the max you can get is 111db at 1 meter - so if you want more you need a HE loudspeaker capable of handling watts.

My Vanguard

1w - 95db
2w - 98db
4w - 101db
8w - 104db
16w - 107db
32w - 110 db. So I just matched your 256 watt Bryston power amp with an Antique Sound Labs or Jolida EL 34 tube amp. And I have had Bryston on these speakers. The ASL sounds better and costs less than 1/4 the price.
64w - 113db
128w - 116db
256w - 119db (granted the 256 watt Bryston will play up here on these speakers - cool man - but 110db is far too loud as it is so gaining 9db for and extra $5000 and getting worse sound is not a good trade just to play at levels you can no longer discern quality is IMO silly.

Tannoy Westminster

1 w 99db
2w 102db
4w 105db
8w 108db
16w 111db (So with an 8-16watt amp (tubes are ok going over their limits remember) you are now getting the same volume regardless of power amp used in system one. There are no other factors to consider - this is the level attained because you have efficient speakers. It's a much better sounding speaker, has far deeper better bass - takes advantage of the best sounding amplifiers - not just lousy sounding high power amps A/B amps

32 w - 114db (that ASL and Jolida will pound the snot out of system 1 even if you have a 6million watt amplifier.

64w - 117db
128w - 120db
256w - 123db (which is the maximum this speaker can handle.

So with the HE speaker you get better sound - deeper bass, endless amp choices and that is the reason this is one of best speakers ever built - granted you're into over 20 grand for it too but cost aside the argument for watts is a non issue if you have HE speakers - and headroom is included. These are the maximums and Tube amps typically can go over their maximums by signficant margins. http://stereophile.com/features/357/

[Ajani]

RGA - Yes, the maximum volume you can get is limited by the power handling of the speakers, so clearly there is no advantage to getting an amplifier in excess of what your speakers can handle...

Also, clearly a HE Speaker means you can use any amp from a 1 watt Sissy to a 2KW Savage...

All that is well and good... however, all that is IRRELEVANT if you don't like the sound of any HE speakers... You like Tannoy Westministers, etc... However, I'm sure E-Stat and Geoffcin chose their planars because they are the best sounding speakers they could afford to buy (in their opinions)...

The point being that it does not matter whether RGA thinks that HE Speakers and low powered amps sound better than anything else or whether Geoffcin/E-Stat think that LE Planars with High Powered amps sound best... All that matters is what each individual prefers... There are no right answers in audio... and we have all been on this forum and in this hobby long enough to know that this a never ending debate, that really just boils down to what sounds best to each of you...

[RGA]

Estat I think you'll agree that your system and budget is quite an exception to the average person my comments are for.

With the typical budget and typical midsize room with people not spending over $70,000 on systems - My comments are directed at the lower end of the higher end market. And generally with the exclusion of panels which are in a serious minority of buyers.

[Feanor]

Volume is a factor of the sensitivity of the speaker, the maximum watts the speaker can handle, and if provided the maximum decibel rating before compression, and impedance of the speaker, and the power supply quality of the amplifier (not quantity rating on the spec sheet).

Looking at a high power amplifier in isolation is a non issue.

If a typical speaker is 87db sensitive and an easy impedance and can take 120 watts then there is no point in buy an amplifier over 120 watts - Period - regardless of tube or SS.

1 w - 87db
2 w - 90db
4w - 93db
8w - 96db
16 w - 99db
32w - 102db
64w - 105db
128w - 108db
256w - 111db (This is the maximum level this speaker can play) You can talk about 3db drops at 2 meters all you want but that is still an apples to apples argument as all the other speakers will have the same issues). So you go out and buy your 256watt Bryston and you play to maximum you get 110db. (and then only in max peaks) Great. Whether you use 256watt amplifier or a 6million watt amplifier you are only ever getting ~110db.

...
Pretty close to the mark. My Magneplanar MG 1.6 are about 86 dB sensitivity; my Monarchy amps are 120 wpc into 4 ohms. I never played anything, even orchestral crescendos, above 100 dB, ergo I have plenty of power as is born out by my experience.

Yes, there are plenty of tube amps that would work fine for me. I fancy a pair of AES Six Pacs (http://www.audioelectronicsupply.com/cgi-bin/audioelectronicsupply.com/view_services.cgi?request=detail2&dept_id=4&aisle_id=41&prod_num=SIX_PACS), not that I'm anything but please with the Monarchys.

Six Pacs ...

http://www.audioelectronicsupply.com/graphics/products/large/six_pacs.jpg

[E-Stat]

Estat I think you'll agree that your system and budget is quite an exception to the average person my comments are for.
True, but that really doesn't change the nature of my speaker choice which is driven by its sound, not efficiency. I could very easily live with a pair of nicely driven Maggie 1.6s or Peter Gunn modified SMGs.


And generally with the exclusion of panels which are in a serious minority of buyers.
What a shame to deny the realism I find they provide.

rw

[Geoffcin]

If a person is using 50 watts to generate his true average listening level, then yes, you'll need 500 watts in order to have 10 dB headroom.

However, I owned a set of Maggie 1.6QRs for several years and drove them very successfully with a pair of 60 watt Dyanco Mk IIIs (modded, but not for more power.) I had no problem reaching an average listening level of 85 or even 90 dB (quite loud for home listening for most people) and never felt the need for more power.

If I recall correctly, the 1.6 QRs were about 86 dB sensitivity, so 1 or 2 watts was giving me an average listening level. The rest of the 60 watts was available for the peaks.

Of course, there are some people who listen at incredibly high levels. I've known a few people like that in my day. As one might say, more power to them. ;-)

If someone is cranking a constant average of 50 watts into a pair of MMGs, I can only imagine what type of volume level they prefer for listening.

It is one thing for a rock band to hit 120 dB in a big arena, or a symphony orchestra to hit something over 100 dB at full tilt in a 1,000 seat concert hall when you're dozens or even hundreds of feet from the players, but I find nothing realistic or attractive with those levels in a home living room.

However, that's just me and there are certainly plenty of big amps out there for those who want them.

Magnepan rates their speakers into 4 ohms, so if they really claim 86dB per watt, it's more like 2 watts. Also very few people listen at 1 meter, especially maggies owners as you would be wearing them like headphones at that distance! Mine are just past 3 meters from my seating and at that distance to create 85dB we're at more like 95dB at one meter. Crank it up to 95dB at my listening distance and your at 105dB at 1meter. With a speaker that has 85dB sensitivity that your asking to produce 105dB and also have headroom for peaks you can see where you would run out of watts fast. With that being said, my 75wpc tube amp has more than enough power to make them sing with most program material.

[E-Stat]

It is one thing for a rock band to hit 120 dB in a big arena, or a symphony orchestra to hit something over 100 dB at full tilt in a 1,000 seat concert hall when you're dozens or even hundreds of feet from the players, but I find nothing realistic or attractive with those levels in a home living room.
Amen. High resolution systems don't need to be played at ear bleeding levels in order to reveal their beauty. :)

rw

[JoeE SP9]

Speaking of Pass Labs and Class A, I'm thinking I'd really covet a pair of XA200.A (http://www.passlabs.com/pass/254/xa2005)'s, (400 wpc @ 4 ohms), to power my Maggies.
:16:

http://www.passlabs.com/pass/wp-content/gallery/cache/87__600x400_xa200_5.jpg

A pair of these beasts is in the range of $35,000, weighs 360 lbs, and sucks 1400 watts at idle.

Yeah, but they don't suck much more at full power. Full Class A amps act like they are producing full power 100% of the time.

Most amps are of the push pull variety. One half of the sine wave is amplified by one set of transistors the other half is amplified by the other set of transistors. Most amps operate in class A up to a certain point. This is usually only a couple of Watts. While in Class A all the output transistors are on even when the sine wave is on the other side of the zero volt reference and they are sitting idle. When an amp switches to Class B the set of transistors needed are switched on as the sine wave goes from negative to positive. The unused transistors are turned off. Any switching distortion generated is masked by the overall signal level.
This can cause switching distortion. It is the distortion generated when a bank of transistors are turned on or off. Class A operation does not have this because all the transistors are always on.

In general the more Watts an amp produces before switching to Class B the larger, more expensive and bulky the power supply becomes. The large power supplies in full Class A amps are necessary because the amp acts like it's producing full power all the time. The heat production is a byproduct of dissipating heat at 100% current draw 100% of the time.

[E-Stat]

Yeah, but they don't suck much more at full power. Full Class A amps act like they are producing full power 100% of the time.
Ironically, they produce less heat when run at full power. When idling, the extra power consumed is dissipated as heat.

rw

[mlsstl]

Geoffcin, I believe you're overstating the volume drop-off past 1 meter. The volume decrease you note is for anechoic conditions or a speaker used outdoors. When a speaker is in a typical residential room the distance drop-off isn't nearly as great.

I'm listening to my second system tonight, so got my sound level meter out. The one-meter pink noise level was about 69 dB. At my listening seat, about 2 1/2 meters, the meter reading varied from about 66.5 to 67 dB. Far less than the anechoic measurements would indicate.

I'm also fortunate enough to have acquired quite a bit of test equipment in support of my hobby over the years (Tek scope, distortion analyzers, power meters, frequency generators, counters and the like) so I'm quite confident in the approximate power figures I gave in the earlier email.

Yes, extra power can make a difference in some situations, but it also brings its own problems. All engineering is a compromise that balances numerous different variables. For me and the way I listen, gobs of extra power just isn't an issue. It is kind of like E-Stat and RGA arguing over their speaker preferences. I've found what works for me and have two systems that give me great pleasure. However, I can easily see that others might prefer something else.

However, the point I first made earlier in this thread is that I know of no recordings that contain the type of dynamic range that would cause a listener who was cruising along at an average listening volume generated by 1, 2 or 5 watts to suddenly need 200 or 500 watts for a peak.

Now if your speakers truly need 50 watts to hum along at average volume, then the hundreds of extra watts start making a bit more sense. But that person isn't a type of listener I can't relate to very much.

[RGA]

Edited due to being argumentative - I apologize if you read it before I deleted it.

[Geoffcin]

However, the point I first made earlier in this thread is that I know of no recordings that contain the type of dynamic range that would cause a listener who was cruising along at an average listening volume generated by 1, 2 or 5 watts to suddenly need 200 or 500 watts for a peak.

Now if your speakers truly need 50 watts to hum along at average volume, then the hundreds of extra watts start making a bit more sense. But that person isn't a type of listener I can't relate to very much.

For sure most high power amps never get to use their reserves, and most people don't listen at high voume on any regular basis, but I would rather have a few dB's headroom than run the risk of hard clipping especially with a SS amp. I too know how to do engineering math and for what I was listening at last night, at my listening distance required power maxed out at about 10 watts. However at the end of Ravel's Bolero I'm sure a few extra dB's of headroom was needed. With a 40 watt amp I would have been very close to clipping, thankfully the amp I was using at the time (I have several) produces double that output.

[E-Stat]

However, the point I first made earlier in this thread is that I know of no recordings that contain the type of dynamic range that would cause a listener who was cruising along at an average listening volume generated by 1, 2 or 5 watts to suddenly need 200 or 500 watts for a peak.
Hmmm. I have a handful that have more than 40 db range. Le Sacre du Printemps places pretty heavy demands on my system. :)

Dynamics (http://home.cablelynx.com/~rhw/audio/power.jpg)

rw

[mlsstl]

Hmmm. I have a handful that have more than 40 db range.

I have a lot of music that has a range of more than 40 dB from the softest parts to the loudest, but as pointed out before, the soft passages aren't meant to be played at an average volume level of 80 or 90 dB!

A good example is an album I recently converted from LP - the 1965 album of Raymond Lowenthal's recordings of Charles Valentin Alkan. This recording of solo piano has great dynamic range from the very soft rendering of Barcarolle to the much louder Finale Presto of Alkan's Symphonie.

If you set the playback level for the Symphonie at a reasonable average of 85 dB in the room, the average level of Barcarolle is much softer, perhaps 70 dB. This does not include the extremely soft passages within the music itself which are easily down in excess of 40 dB from the loud passages on the recording.



You didn't state which Rite of Spring performance you have, but I would be very surprised if the parts you mention as 40 dB down in volume were meant to be played at a loud average level. I suspect if 80, 90 or even 100 dB is the average volume for the louder parts, that your soft parts were meant to be heard in the room at 40, 50 or 60 dB SPL. At least that's the way I've always heard the performance - the quiet passages are precisely that - they aren't played at a higher volume.

[E-Stat]

You didn't state which Rite of Spring performance you have, but I would be very surprised if the parts you mention as 40 dB down in volume were meant to be played at a loud average level.
That's certainly true, but one must set the output level such that it can handle the loudest passage(s) without clipping - even if they only occur for a fractional amount of the playing time which may be measured in seconds. That particular version is the ASO on Telarc.

rw

[frenchmon]

Any one heard of these? http://www.jamnaudio.com/claytonaudio.html

Frenchmon, care to guess why they are called "Clayton" Audio? They are pretty expensive as well. Not like a Pass monoblock but several thousand. I heard a pair of the CA monoblocks drive the Dynaudio Sapphires and it was amazing.

That KSA would be a sweet amp.

He Mr.Peabody. I think that's a local company...am I correct? If so do they have a show-room? Theirs a few audio company's located here....ADD speakers, Herron Audio, Dynavector, Vibrapods and a few others. I wonder if these places have a show room?

frenchmon

[mlsstl]

...but one must set the output level such that it can handle the loudest passage(s) without clipping

Granted, but that's not a particularly complicated situation. Digital material has a pretty absolute maximum volume for its output signal. The loudest possible signal from your over-compressed, peak-limited pop music CD is at the same level as for your most refined classical recording.

LPs and tapes are not quite so precise in their output limitation but still, there are no giant surprises lurking. I noted before that I've transferred a lot of LPs and open reels to digital so I get a very exact visual indication of what's on the analog source.

Without fail, the only giant dynamic peaks I ever see well beyond the average loudness level are invariably a click or pop in a vinyl record. This is for everything from the ordinary pop/rock pressings to classical to Sheffield type recordings.

Open reel recordings are limited by tape saturation issues once out of their linear range. Similarly, LPs have a set of limitations that revolve around playing time and the amount of low bass content. A record producer is also aware he has no control over the playback systems of the end users so needs to keep modulation levels within generally acceptable parameters for stylus tracking.

The only recordings that I know of as exceptions are specialty ones. Tom Danley once did a recording of fireworks that will challenge a system beyond any available commercial recording, but for me that is a novelty. It is certainly not something I'll elect to build my system around. (Note, you can download the wav file from his web site at http://www.danleysoundlabs.com/technical%20downloads.html.)

The net result is that, during the average loud passages of the vast majority of musical recordings, there is simply little chance that some hidden 15 dB or 20 dB peak is lurking, just begging to be clipped by our system. Even in classical music, most of the unusually large peaks were lost during the recording process due to the natural compression imposed by mikes, recording consoles and other devices once pushed out of their linear range. And, as we know from pop/rock recordings, there is a lot of artificial processing that can be further lumped on top of this.

[E-Stat]

that's not a particularly complicated situation.
It's not complicated at all - just requires more power to maintain equally realistic average levels with wider dynamic range content.


Tom Danley once did a recording of fireworks that will challenge a system beyond any available commercial recording, but for me that is a novelty.
I downloaded that some time back when he first posted it over at AA.


The net result is that, during the average loud passages of the vast majority of musical recordings, there is simply little chance that some hidden 15 dB or 20 dB peak is lurking, just begging to be clipped by our system.
It is always the exceptions that drive ultimate requirements. :)

rw

[mlsstl]

It is always the exceptions that drive ultimate requirements.
And, in all my years in this hobby with well over 40,000 songs in my collection, I've still never seen or heard one of those exceptions on a music recording.

I suppose I could spend a lot of time completely revising my system in preparation for the fraction of a second that may or may not ever occur, but that doesn't make a whole lot of sense to me.

If it works for someone else, well, once again, more power to 'em. ;-)

[E-Stat]

I suppose I could spend a lot of time completely revising my system in preparation for the fraction of a second that may or may not ever occur, but that doesn't make a whole lot of sense to me.
May not ever occur? I have no idea what you are saying. I have perhaps two dozen or so favorite recordings of very high quality and wide dynamic range that determine for me how much power I need. Then again, with a higher budget I wouldn't even think about it. YMMV.

rw

[mlsstl]

May not ever occur? I have no idea what you are saying. I have perhaps two dozen or so favorite recordings of very high quality and wide dynamic range that determine for me how much power I need.
I've been very specific with my examples and explanations in my prior posts. This is based on the more than 2,000 recordings I've transferred to digital. Adobe Audition gives a very clear view of the dynamic range involved of everything I run through it.

You earlier gave an example with a 40 dB dynamic range, but I pointed out that that the soft parts of a music piece should be played softly. Take a medium efficiency 85 dB/watt speaker and those quiet sections of a recording down at 60 dB SPL are only consuming four one-hundredths of a watt. That is why some music listeners are more concerned about the low-wattage end of things more than the high end.

The question is what peaks are still above the loud parts. The answer, as is clearly shown in my prior post concerning the maximum peak recording level that applies to all formats, is not much.

I've got a meeting to attend this evening, but afterward I'll get one of my fancy classical recordings with good dynamic range out and post a screen shot from Audition. Perhaps a picture will better illustrate things.

[E-Stat]

You earlier gave an example with a 40 dB dynamic range, but I pointed out that that the soft parts of a music piece should be played softly. .. Perhaps a picture will better illustrate things.
What I said was "more than 40 db". There is no reason to post pictures, because I'm not talking theory or hypothetical efficiency ratings, but direct experience with my system. I'll repeat: it is only for a dozen or so recordings that I need the power I have (actually about 3 db would be better). I know exactly what the live levels would be for several ASO Telarcs since I've been in that hall countless times and have participated in one of the recordings. Your system is likely very different from the one to which I refer. The two other ones require far less power. With the garage system, I rarely need more than 4 watts unless I want it VERY LOUD.

rw

[mlsstl]

Here's an image from the finale of Wagner's "Ride of the Valkyries"

Note the orchestra is cranking along with a lot of fervor at full tilt. You can see the volume bar at the bottom of the screen shot shows right at - 6 dB. That means there is 6 dB of headroom left for peaks. Nothing louder than that will be reproduced. There is simply nothing available for 20, 15 or even 10 dB peaks.

This is pretty typical of classical recordings. The start of the screenshot is about -24 dB. The decaying sound level right before electronic fadeout is right at -40 dB.

You can see we have about 5 or 6 peaks that make use of some or all of the remaining 6 dB of headroom. As noted earlier, there simply isn't a massive amount of headroom on recordings above the average loud portions of a composition.

I'll certainly agree that: 1) some people listen at much louder average levels than I do. The guy that uses 50 watts on average will probably benefit from those hundreds of watts. They are certainly free to pursue that, though it simply doesn't interest me and I don't require it for my system.

2) Some people simply prefer having an amp with enormous power reserves at their disposal. That may well influence how their system sounds to them.

My primary point all along has been is that if you are getting the volume you want on the average loud portions of a record from just a couple of watts, there is nothing on a recording that is going to produce a sudden demand for 200 or 300 watts. If this person prefers the more powerful amp it is likely due to some other factor.

http://www.rzootoo.com/wagner/wagner_valkyries.jpg

[Mr Peabody]

mlsstl is talking about LP's, is that what you refer to also , E-stat?

Frenchmon, Clayton is local. I didn't realize or forgot about Herron, I'd really like to hear some of that. MFP has some of the Clayton around. I'm not sure if any one displays the Herron but I think I will see if I can email them.

Sometimes plots and curves look good on paper but don't seem to match real world use. My MV60 is rated at 50 wpc and it was good with my Dyn's to a comfortable listening level and could have been fine for some but I felt my system needed more power. With them being mono the power is sufficient unless reaching real loud levels. I should get my meter out sometime and see what SPL some of my listening is. I know I have a Reference CD of Classical, Music for Pipes & Brass, it takes a Krell to get that to slam like it's supposed to. I have had the amps reach their limit before but I never listen at that level. I never got my 500i to it's limits. Nor, did I the 300i as far as that goes.

[E-Stat]

Here's an image from the finale of Wagner's "Ride of the Valkyries"
Which is significantly less "spikey" than my example. Yours looks more like pop music. It is those infrequent spikes that require more juice.


Note the orchestra is cranking along with a lot of fervor at full tilt. You can see the volume bar at the bottom of the screen shot shows right at - 6 dB. That means there is 6 dB of headroom left for peaks.
You'll notice with mine that the right channel has already clipped.


This is pretty typical of classical recordings.
My example is an atypical recording. One of those exceptions to which I refer.


My primary point all along has been is that if you are getting the volume you want on the average loud portions of a record from just a couple of watts, there is nothing on a recording that is going to produce a sudden demand for 200 or 300 watts.
There is a reason why Sound Lab burns in their speakers at the 800 watt level. I've met the designer and visited their facility in Utah.

rw

[E-Stat]

mlsstl is talking about LP's, is that what you refer to also , E-stat?
I'm talking about any source for my main system to reach peaks of about 90 db. It takes 600 watts. The stats are not efficient and require more grunt.

rw

[mlsstl]

Which is significantly less "spikey" than my example. Yours looks more like pop music. It is those infrequent spikes that require more juice.

"Pop music"? Hmmm, just can't have a conversation without a few digs? Interesting.

The frequency or infrequency of a spike is irrelevant to the subject. Zero dB is zero dB on a recording, regardless of where it came from or how often it happens.


You'll notice with mine that the right channel has already clipped.

Not sure what you mean by this. I see nothing attached to examine. Could you clarify?

Plus, if a peak is clipped on the recording itself, no amount of power in the world from the amp will unclip it.

[Ajani]

As we can see from the posts in this thread so far:

Amplifier Power requirements vary from user to user... Persons like RGA, prefer above average to High Efficiency Speakers with low powered Class A and/or Tube Amps... Others prefer Low Efficiency Speakers that like to be dominated by a big brute (I didn't make up that line - I read it in a review once)... Personally, I like 50 Watt Amps driving anything from Just below Average to Fairly Efficient Speakers (in a small to medium room)...

I've ruled out Class A amps, simply because of the the heat and cost to get a 50 Watt Class A... And besides, I am feeling the strong urge to embrace the love whose Naim I dare not speak, as a Christmas present to myself...

[audio amateur]

I've ruled out Class A amps, simply because of the the heat and cost to get a 50 Watt Class A... And besides, I am feeling the strong urge to embrace the love whose Naim I dare not speak, as a Christmas present to myself...
Ummm, what are you going to drive with a Naim?

[Ajani]

Ummm, what are you going to drive with a Naim?

Naim? Who said anything about Naim??? :prrr:

Hypothetically, If I was to get a Naim, I'd be pairing it with Revel....

[E-Stat]

"Pop music"? Hmmm, just can't have a conversation without a few digs? Interesting.
It's not a dig. Your example is not particularly dynamic.


The frequency or infrequency of a spike is irrelevant to the subject. Zero dB is zero dB on a recording, regardless of where it came from or how often it happens.
My point is the spike is just that - a major dynamic contrast. Here's another example of a fun piece from Harry Potter and the order of the Phoenix. This is the "Hall of Prophecy" cut - a very emotional piece with "raise the hair on your arms" dynamic impact. Click here (http://home.cablelynx.com/~rhw/audio/prophecy.jpg) to view. Another is from John William's score of Memoirs of a Geisha. Here is the "Rooftops of Hanamachi" where Sayuri is trying to find her sister. It is another emotional piece with impact. Click here (http://home.cablelynx.com/~rhw/audio/rooftops.jpg) for that example. One last falls into the "f--ing awesome" category. Here is a cut of Chinese drum music. The first time I heard this it was played on Nola Grand References with Krell amps on the woofer towers and VTL Wotans on the mains. The opening bars will STARTLE the crap out of you with its dynamic impact. Look here (http://home.cablelynx.com/~rhw/audio/hokman.jpg) for this example. Etc., etc..


Not sure what you mean by this. I see nothing attached to examine. Could you clarify?
Since the image was large, I made it a link instead. Click the blue link that says "Dynamics"


Plus, if a peak is clipped on the recording itself, no amount of power in the world from the amp will unclip it.
No debate there.

rw

[Mr Peabody]

Come on Ajani, what are you thinking about getting, how bad could it be? :) Are you springing for that Sherwood/Bose system you've dreamed about?

[Ajani]

Sherwood/Bose system
:eek6: :eek6: :eek6: :eek6: :eek6:

[frenchmon]

mlsstl is talking about LP's, is that what you refer to also , E-stat?

Frenchmon, Clayton is local. I didn't realize or forgot about Herron, I'd really like to hear some of that. MFP has some of the Clayton around. I'm not sure if any one displays the Herron but I think I will see if I can email them.

Sometimes plots and curves look good on paper but don't seem to match real world use. My MV60 is rated at 50 wpc and it was good with my Dyn's to a comfortable listening level and could have been fine for some but I felt my system needed more power. With them being mono the power is sufficient unless reaching real loud levels. I should get my meter out sometime and see what SPL some of my listening is. I know I have a Reference CD of Classical, Music for Pipes & Brass, it takes a Krell to get that to slam like it's supposed to. I have had the amps reach their limit before but I never listen at that level. I never got my 500i to it's limits. Nor, did I the 300i as far as that goes.

If you do get a chance to listen to the Herron amps let me know....I thik they are all tubs.

I think your amps where 50 watts perchannel and you had them modded so they are 100 mono correct?

frenchmon

[LeRoy]

So what is "pure class A". Just about every "pure class A" amp is low in wattage and very expensive. How does a "pure class A" amp at 35 watts per channel compare to a non-pure class a amp at 200 watts per channel?

frenchmon

Well it seem like I am late to this thread as well...

With regard to your original inquiry, I think Belles and Pass Labs make the benchmark class A amplifiers with Belles being more affordable. Yes, the class A amps do get quite warm and do need space around them to keep them ventilated. With regard to quality of sound, I simply love the SA30 & VT01 over anything I have heard to date including my Soloist (purchased as a demo units for $1100). I have yet to hear any distortion from my Soloist and have yet to hear any distortion through the SA30 VT01 combination regardless of volume setting.

I have my XRAY paired up with the Soloist 3 & 5 and it's a very good musical match. The XRAY also is a great match with the SA30 & VT01 but the XRAY is not quite in the same
league as the Lector CDP-7T/Mk III (now selling for roughly K$5.5).

For reviews of Belles equipment..

Statement Series, check out these particular reviews
SA 30 amp
VT-01 pre-amp

For the Soloist, check out the reviews
Soloist 3 Preamp
Soloist 5 Amp

The reviewed units, SA30 and VT01 (the units reviewed on Soundstage), are the very units I have had the pleasure of listening to at my local audio dealer's home. I did hook up the XRAY into this amplification and the speakers were the Reference 3A Episode.

Depending on how long you are willing to wait, my local audio dealer advised that Belles in coming out with a new integrated amp that basically is a combined and upgraded Soloist.

http://www.powermodules.com/power_modules/Home.html

Good luck with the research and have fun shopping.

LeRoy

[blackraven]

Belle's makes nice stuff. A good friend of mine owns a Belle's Hot Rod amp and it sounds great.

[RGA]

As we can see from the posts in this thread so far:

Amplifier Power requirements vary from user to user... Persons like RGA, prefer above average to High Efficiency Speakers with low powered Class A and/or Tube Amps... Others prefer Low Efficiency Speakers that like to be dominated by a big brute (I didn't make up that line - I read it in a review once)... Personally, I like 50 Watt Amps driving anything from Just below Average to Fairly Efficient Speakers (in a small to medium room)...

I've ruled out Class A amps, simply because of the the heat and cost to get a 50 Watt Class A... And besides, I am feeling the strong urge to embrace the love whose Naim I dare not speak, as a Christmas present to myself...

An Acoustat owner - Mr. Acoustat - has difficult to drive Stats - he recently bought a Grant Fidelity Rita integrated 45 watts pure class A power amp (it does have peak ability to 450watts). And best of all the amp runs cooler than your average Receiver due to a unique design. And I mean it - it runs cool!

So it is cool running tube amp, and can drive pretty much anything with no problem - I have seen nothing built better for $4k - except maybe the Shengya PM 150 monoblocks I have on hand. $1200 each built like a tank - cool running tube hybrid A/B monoblock amplifiers and 300 watts into 4ohms.

The downside of the Rita is that it is so ridiculously heavy 145lbs that you can put your back out moving it around. http://www.soundstageav.com/onhifi/20081001.htm Their price of $5299 has been reduced to $4200US

[Mr Peabody]

A guy had a pair of Acustats on CL for $250.00. By the time i contacted him they were gone. I really didn't have the room for them. He was one of those guys who was into audio for a while and eventually the system ended up in the garage and he just wanted to get rid of it. Some one got an unreal deal.

Do those Shengya sound good? That's some cheap tube watts.

[mlsstl]

E-Stat, sorry for the delayed response, but it was a hectic weekend.

I took a close look at your music piece. While it looks impressive, the average level in the loud section is about 8 to 9 dB down from zero. That isn't all that terribly different from what I posted earlier.

The scale range one uses for graphic display has a lot to do with appearances. From zero dB on your graph to -6 dB is half way to the infinity mark. The scale markings on your graph are such that they tend to magnify things to make for more dramatic looking peaks.

Your soft material before the loud part is about 18 dB down.

The front end of the piece I clipped from my music selection also is around 18 dB down, so even though yours has a longer selection of soft volume material, and even though yours "looks" more dramatic, there isn't all that much difference in dynamic range.

Your peaks are about 3 dB higher than the peaks in the piece I used.

You've also stated previously that you have vary inefficient speakers and need 50 watts just for an average volume.

Several messages ago I clearly stated that if one needs 50 watts for average power, then having hundreds available for peaks is very reasonable. If just one or two watts is giving your average volume, then those enormous power reserves make less sense.

As such, I'm not quite sure where the point of disagreement lies.

[E-Stat]

E-Stat, sorry for the delayed response, but it was a hectic weekend.
Apology unnecessary.


I took a close look at your music piece. While it looks impressive, the average level in the loud section is about 8 to 9 dB down from zero. That isn't all that terribly different from what I posted earlier.
Perhaps, but it is not the average levels to which I refer. If the piece you're talking about is the first one (Rite), you're cruising along at -20 db for nearly two minutes then WHAM - full gain! Wait two seconds, then again! The "Rooftops" piece shows even more contrast between average and peak levels.


The scale range one uses for graphic display has a lot to do with appearances. From zero dB on your graph to -6 dB is half way to the infinity mark. The scale markings on your graph are such that they tend to magnify things to make for more dramatic looking peaks.
Far more dramatic scaling? 50% vs. 40%? It sure doesn't look like the Adobe application is much different from Sony's.


The front end of the piece I clipped from my music selection also is around 18 dB down, so even though yours has a longer selection of soft volume material, and even though yours "looks" more dramatic, there isn't all that much difference in dynamic range.
Yet the average levels are quite different when you consider all the examples I've provided. Therein lies the difference.


As such, I'm not quite sure where the point of disagreement lies.
Probably not. On the other hand, I certainly don't power my system "in preparation for the fraction of a second that may or may not ever occur". It is those fractions of a second that I most certainly use every last milliwatt of power I have to achieve peaks of barely over 90 db measured at listening distance.

rw

[RGA]

A guy had a pair of Acustats on CL for $250.00. By the time i contacted him they were gone. I really didn't have the room for them. He was one of those guys who was into audio for a while and eventually the system ended up in the garage and he just wanted to get rid of it. Some one got an unreal deal.

Do those Shengya sound good? That's some cheap tube watts.

I am currently away from home and can't do a lot of evaluations - I was reviewing something else so I have not given much audition to the Shengya monoblocks. I am also waiting for a proper CD player to come in to give both the Rotel and Shengya's a proper evaluation. I am hoping to get an Audio Note CD player soon to get a better foundation for my digital front end.

But I can say I like what I have heard so far - of course that power is lost on my speakers. But the point was to have something like this to be able to review tough to drive speakers. Obviously the OTO limits my options.

I do have a few exceptions in the hard to drive speakers camp that I like - Soundlabs coincidentally.

[mlsstl]

Perhaps, but it is not the average levels to which I refer. If the piece you're talking about is the first one (Rite), you're cruising along at -20 db for nearly two minutes then WHAM - full gain! Wait two seconds, then again! The "Rooftops" piece shows even more contrast between average and peak levels.

If you are playing the soft section of the Rite of Spring at a loud 90 dB, then you intrinsically listen to music differently than I. I think the quiet sections of compositions should be played quietly.

If I'm running the quiet section at 70 dB in my room, my particular system is not going to need a zillion watts to hit the 20 dB louder "WHAM" peak at 90 dB.

And it really doesn't matter if this 20 dB happens every two seconds, every 30 seconds or only once. The recording itself has a maximum limit and there is nothing hidden beyond that. If the amp is decent quality and adequate to deliver the needed power once, it can also deliver it every two seconds.

My comment about the scaling was that while your version "looks" far more dramatic in terms of dynamics, it really isn't that much more when you run the actual numbers. Your loud section has 8 or 9 dB peaks above average. That's pretty good for a lot of recordings, but hardly unheard of. You keep claiming an unusually large dynamic range for this piece that I simply don't see when I look at it.

I guess this qualifies as a fundamental difference in perspective on the issue. The conversation has turned repetitive so there's not a lot of point in our continuing. Anyone who is interested can read through and come to their own conclusion.

The last word is yours and don't forget to enjoy your music!

[Ajani]

If you are playing the soft section of the Rite of Spring at a loud 90 dB, then you intrinsically listen to music differently than I.

Actually, I think E-Stat was saying that his speakers are so inefficient that it takes a load of power for him to hit the peaks at 90DB... So the soft sections might even be lower than what you listen at...

[mlsstl]

Ajani wrote: "Actually, I think E-Stat was saying that his speakers are so inefficient that it takes a load of power for him to hit the peaks at 90DB"
Actually, if you read back a bit, there isn't disagreement about that issue.

[E-Stat]

... don't forget to enjoy your music!
That I do on a daily basis! :)

rw

[Carlos Ved]

Hi. I am from Portugal. My 17 year old amp no longer works. Apparently it is the On-Off switch which is broken. Locally the distributor is unable to source the right component which looks lika a small rod with a base and 4 pins underneath. Can anybody help ?

[audio amateur]

Hi. I am from Portugal. My 17 year old amp no longer works. Apparently it is the On-Off switch which is broken. Locally the distributor is unable to source the right component which looks lika a small rod with a base and 4 pins underneath. Can anybody help ?
Perhaps you can contact Musical Fidelity in the UK and ask to have the piece sent? Or try another MF dealer in Portugal?

[jrhymeammo]

Wow,

See this is what happens when I'm working 70 hours a week. Missing out on some great threads here at AR. Coincidentally I had purchased a pair of Aleph5 made by Tim Rawson.
Pure Class A at 70/8 ohm, 100/4 ohm with 100,000 uf.

Time to crank my AC in January!!

JRA

[Mr Peabody]

JRA, I wonder why the power doesn't increase more than it does into 4 ohms. It looks like there's reserve, maybe just not a lot of current? Not familiar with that line of amp.

[jrhymeammo]

Mr. P,

I try to stay away from technical aspect of this hobby. So to answer your question, I have no idea. Tim Rawson is well known for what he fabricates based on PASS Labs schematics, so I just hoped on them. They are clone of the PASS Labs Aleph 5.
BTW, Aleph 5s were high-current design.

Here is a link if you feel like reading.

http://cygnus.ipal.org/mirror/www.passlabs.com/a5lit.htm


From what I understand, Tim just enjoys making amps, and he sells them on Agon to cover his cost. Defintely, one of the good guys. He's username is Rawsonte on Agon.

JRA

[Mr Peabody]

Ah, the Aleph 5 only has two gain stages and leaves out the "auxiliary pull circuitry" which allows more power at low impedances. It is still stable though according to the link you posted. Apparently, the benefit side is more immediacy, warmth and detail.

Thanks

[jrhymeammo]

Ah, the Aleph 5 only has two gain stages and leaves out the "auxiliary pull circuitry" which allows more power at low impedances. It is still stable though according to the link you posted. Apparently, the benefit side is more immediacy, warmth and detail.

Thanks

Warmth is defintely there. This is my first SS Class A amp, and I'm quite amazed.
I have them connected directly from a Yamaha CDP w/ variable output.
I will eventually need to get a hold a tube preamp/linestage, but at this moment I got a huge smile. Smooth clarity with lots of grip.

Big thanks to Nelson Pass and Tim Rawson!!
JRA

[Carlos Ved]

[QUOTE=audio amateur]Perhaps you can contact Musical Fidelity in the UK and ask to have the piece sent? Or try another MF dealer in Portugal?[/Managed to contact MF in the UK. They are sending me a switch. Thanks for the suggest]

[Carlos Ved]

Managed to contact MF in the UK. They are sending me a switch. Thanks for the suggestion.

[audio amateur]

Managed to contact MF in the UK. They are sending me a switch. Thanks for the suggestion.
Nice, I hope it works out! :)

[Amirulddin]

I like so much about music. I'm now searching for quality integrated amp. I've tried reading a lot about this area. But everytime i ask the hi fi dealer, they often told me their amps are the good one and those amplifiers i'd mention to them are not so good. I also want to learn about the hi fi technical. I think i need a long time to mastered this area. At home, i have a small room that i make it as my studio / music room. I appreciate you all as i'm sure you all are expert in hi fi area. Nice to read all the reviews.... Tq.

[Mr Peabody]

Amirulddin, welcome to AR. Where do you live? The secret is to not listen to the hype of sales people and trust your own ears, buy what makes you happy when you hear your favorite music. If possible try to audition what you want to buy in your own room. Most high end shops worth their salt will allow for this in some fashion.

[Poultrygeist]

If that 35 watt amp is a tube amp it may sound just as loud. With a tube amp you won't hear the distortion at higher volumes like you will with a solid state. I believe most SET amps run in pure class A.

I have a pair of very inefficient Aerials (84dB) speakers. They sound louder with a Yaqin tube amp of 50 watts than with a double-the-power Classe soild state.

Class A amps do offer the purist sound but their down side is excessive heat. I have a small fan blowing over the tubes of my SET amp.

[JoeE SP9]

With only one device handling both ends of the signal it would have to be class A.