Mono block questions!

[blackraven]

Ok, I need some help from some of the Elitist Audiophiles concerning monoblock amplifiers. I'm thinking about upgrading my Magnepans to the 3.6R's and if I do I want to upgrade my amplifier. I was thinking about using my Adcom as a preamp and buying a pair of Outlaw Audio mono blocks rated at 300wpc at 4ohms. The Outlaw monoblocks are fairly inexpensive vs a 2ch amp. I've also been looking at a B&K 2ch amp at audiophile liquidators. They have the Reference 200.2 series 2 amp rated at 375wpc for $1100.

My question is- what are the benefits and disadvantages of using monoblocks vs a 2ch amplifier?

Thanks!
Larry

[Feanor]

Ok, I need some help from some of the Elitist Audiophiles concerning monoblock amplifiers. I'm thinking about upgrading my Magnepans to the 3.6R's and if I do I want to upgrade my amplifier. I was thinking about using my Adcom as a preamp and buying a pair of Outlaw Audio mono blocks rated at 300wpc at 4ohms. The Outlaw monoblocks are fairly inexpensive vs a 2ch amp. I've also been looking at a B&K 2ch amp at audiophile liquidators. They have the Reference 200.2 series 2 amp rated at 375wpc for $1100.

My question is- what are the benefits and disadvantages of using monoblocks vs a 2ch amplifier?

Thanks!
Larry

Of course, monoblocks necessarily have complete and separate power supplies which might be good thing. However I don't think sound quality is necessarily reduced by having two channels in one chassis. Undoubted advantages are:

Two monoblocks of a given performance will be lighter and easier to handle than one stereo amp;
Monoblock can be placed closer to the speaker. Many people believe it's better to have shorter speaker cables with longer interconnects. If the pre to amp signal is truly balanced, there will be noise rejection along the interconnect runs.BTW, these Class A Monarchy SE-100's will kick the crap out of anything from B&K much less Outlaw ...
http://buy.audiogon.com/cgia/cls.pl?ampstran&1202746127
despite slightly low power. I believe I've seen pairs of overstocks on sale direct from Monarchy Audio for about $1200 ...
http://www.monarchyaudio.com/

[Mr Peabody]

It also seems that no matter how good, or balanced, or mirror image, a stereo amp is, monoblocks still some how give a better imaged sound stage.

[blackraven]

Thanks for the info guys. Its much appreciated! Cost is a concern here, thats why I've been looking into the Outlaw mono blocks and the BK amp. If I upgrade to the Magnepan 3.6's and the Cambridge 740c or 840c CDP., I'm looking at $4500-5000. The Outlaw mono's are $350 each. It's definitely a trade offf looking at the cost/benefit.

BTW, my wife ordered both the Cambridge 740c and the Marantz SA8001 SACDP for me to compare side by side. She doesnt know that I know about it. Unfortunately, she ordered them online for christmas but doesnt realize that you get a confirmation email. My wife is not very computer literate. I'll have to act very suprised come christmas.

I may have to send both CDP's back and get the 840c!

[Feanor]

Ok, I need some help from some of the Elitist Audiophiles concerning monoblock amplifiers. I'm thinking about upgrading my Magnepans to the 3.6R's and if I do I want to upgrade my amplifier. I was thinking about using my Adcom as a preamp and buying a pair of Outlaw Audio mono blocks rated at 300wpc at 4ohms. The Outlaw monoblocks are fairly inexpensive vs a 2ch amp. I've also been looking at a B&K 2ch amp at audiophile liquidators. They have the Reference 200.2 series 2 amp rated at 375wpc for $1100.

My question is- what are the benefits and disadvantages of using monoblocks vs a 2ch amplifier?

Thanks!
Larry

Larry, you seem like a guy who know what he wants, but ...

I'd recommend upgrading to much better amplification before you upgrade from the MG 1.6QR's to the 3.6R's. Personally I'd kill for a pair of 3.6, but the 1.6 aren't bad, (I have a pair myself). More importantly either speaker will benefit from a much higher quality amplification than either what you've got or what you're proposing. Furthermore, I suspect you will actually hear more difference, (viz. improvement), by making the big step up in amplification rather than the speakers.

I'd love a Pass X150.5 or just the X150, (both 300 wpc @ 4ohms) ...
http://www.passlabs.com/amplifiers/x150.htm

There's a used X150 on Audiogon right now for asking $1800 which you can afford if you postspone the 1.6 => 3.6 upgrade ...
http://buy.audiogon.com/cgia/cls.pl?ampstran&1203221370

You'll want a good preamp too. A Pass X2.5 would be nice; see a used on on Audiogon ...
http://buy.audiogon.com/cgia/cls.pl?preatran&1202012220

Or nice tube preamp with balance outputs such as the BAT Vk-3i, a bit cheaper than the Pass pre ...
http://buy.audiogon.com/cgia/cls.pl?preatube&1202935817

Incidentally, the Monarchy's I mentioned earlier would be easily superior to the Outlaw or B&K with the 1.6's and probably the 3.6's too with most music at reasonable listening levels.

[Mr Peabody]

That was a cool thing your did. Let us know how the comparison went.

Feanor has a good idea. The Adcom is probably adequate but you might be surprised what the 1.6 will do with quality amplification.

www.spearitsound.com has a pair of Marantz monoblocks used for $380.00 a pair. They are only 125 watts though. I believe these have big brothers that received some good press.

[blackraven]

Thanks guys i'll take it all into consideration.

[Slippers On]

Hi Blackraven, guess you've had a Very Mery Christmas by now:16:

Monos will, by definition because of their separate power supplies, give better sound. In My Humble Opinion. You will see by my own collection I prefer Monos. There is a reason, and I hope you will discover this.

Play on

Slippers On

[Mr Peabody]

Slipper, interesting, I see you have problems deciding between the Krell and tubes as well. How do you like the Shanling CD player? What, if any, units did you compare it to? Have you heard any Audio Note gear?

[blackraven]

Thanks Slippers, I'm leaning on getting the Outlaw Mono blocks. I know there are better, but they put out 300wpc at 4ohms and will match my Magnepans very well. Right now I'm pushing 228wpc on my Adcom AV receiver into 2ch. I've checked the outlaw forums and many of the people that are using the mono's have magnepans and they love the mono's.
And for about $350 per monoblock with good spec's, I dont think I could go wrong. I'll just use the preamp of my Adcom till I decide if I need a dedicated 2ch preamp. At this point in time with paying for college for my kids buying anything higher end is out of the question.

[Slippers On]

Slipper, interesting, I see you have problems deciding between the Krell and tubes as well. How do you like the Shanling CD player? What, if any, units did you compare it to? Have you heard any Audio Note gear?


Hi Mr P,

It's not so much that I have problems between the Krells and tubes, it is just that I wanted everything and I hate moving stuff on. I prefer to keep, collect and allow myself the choice.

The Rogers E40a tube is in-fact an Audio Note integrated tube amp. It covers the Rogers name because it was specifically designed for both the Rogers LS3/5a bookshelves and the JR149 bookshelves. (Jim Rogers of BBC fame). Audio Note were given the job of building the units and have their name on it. It is an integrated amp with phono stage pushing out 40Watts class A per channel. My unit was tweaked especially for the London Hi-Fi show of 2002 see here http://www.g4dcv.co.uk/show.html
I use the E40a with a set of JR149s for small room listening.

Regarding the Shanling CD-T300, I suppose I bought this more for aesthetics at the time. I am extremely happy with it. I know it is not everyones cup-of-tea but I like the design. As I moved house recently it sits, like a lot of my gear, in boxes awaiting a new house build. When it comes out later this year I intend wiring in up with the valve pre-amp, the Krell monos and the Townshend full range speakers. I didn't compare it with many CD players. It was put up against one of the Wadia players but this was more of interest to the salesman....If the Wadia sounded better I would not have bought the Wadia, I would only have had second thoughts about the Shanling. The Shanling won anyway. I told the salesman, Kronos Hi-Fi in N. Ireland, to take the Shanling home himself and give me his opinion..which I valued.

Slippers On

[frenchmon]

Thanks for the info guys. Its much appreciated! Cost is a concern here, thats why I've been looking into the Outlaw mono blocks and the BK amp. If I upgrade to the Magnepan 3.6's and the Cambridge 740c or 840c CDP., I'm looking at $4500-5000. The Outlaw mono's are $350 each. It's definitely a trade offf looking at the cost/benefit.

BTW, my wife ordered both the Cambridge 740c and the Marantz SA8001 SACDP for me to compare side by side. She doesnt know that I know about it. Unfortunately, she ordered them online for christmas but doesnt realize that you get a confirmation email. My wife is not very computer literate. I'll have to act very suprised come christmas.

I may have to send both CDP's back and get the 840c!

So have you had a chance to compare the 740c and SA8001?

Let us know.

frenchmon

[Mr Peabody]

The E40 looks like a sweet amp. Shanling does make some good looking gear. I had heard the CD players were pretty good is the reason I asked.

[blackraven]

Frenchmon, see my thread in digital domain on reviews of these 2 CDP's. In a nut shell, I prefered the 740c over the marantz. However, if you have a bright sounding system, then avoid the 740c and go with the Marantz.

[O'Shag]

What's even better than two Outlaw monoblocks..... is four, running biamped, a solution to keep in mind BlackRaven, should your new Maggies have bi-amping capability. Any shortcomings in the Outlaw will be significantly reduced, because the headroom will be significantly increased. And most important for us real world folks with significant others and bills to pay, this should keep in line with your budget. If they are $350 ea, then you'll have oudles of power for $1,400.

I would agree with Feanor on some observations. There are, in all likelyhood, better amps to be had, but at a much higher price. For solid state, an example would be the Bryston amps or into expensive territory, the Mark Levinsons.

On the subject of monoblocks; there is a definite benefit to having seperate power supplies in two seperate chassis (monoblocks). In both of my Audio Research Classic monoblocks (120 and 150) they recommmend each mono be connected to its own circuit branch. Each Classic 150 monoblock for example runs in enriched AB and at idle uses 440 watts at idle and 650 watts at rated output (Even my No 27s soak up 240watts each at idle). Power-supply energy storage is a massive 650 joules per monoblock leading to a rise time of 2 microseconds and a slew rate of 25 volts/microsecond per monoblock. In English, this translates to massive instantaeous power that a one-chassis amplifier cannot deliver unless it is gi-normous and weighs well over 200 lbs (digital switching amps excepted as they use an entirely different method to deliver power).

I would also agree with Feanor that an additional POSSIBLE benefit to the monoblock configuration is that it allows each unit to be placed close to the speaker, facilitating shorter speaker cables, which many seem to advocate. Personally, I think speaker cable length is obsessed over a bit too much. as long as one stays within 1/2 a meter its ok..JUST KIDDING. Actually,up to 5 or 6 metres I can't see making much of a difference. I think this is just another myth the audio-jewelry cable manufacturers have concocted to convince us we should pay 2,000 for one lousy meter of cable.

Granted a pair of stereo amps used in bi-amp mode (such as the pair of Mark Levinson No.27s I use) produces better sound than just one, but I experience even higher performance levels with my Classic monoblocks (150 and 120) running in a biamped configuration.

My constant trying of new configurations, and research, has led me to believe that the impedence problems of speaker crossovers and the resultant drain on the amplifiers usable power is more of a concern and potential detriment to obtaining maximum performance. A surprising amount of an amplifier's usable power can be soaked up by the crossovers, even well-designed ones. This may be different for Maggies - I don't know. What I do know (from trying different things) is that plenty of headroom is key to getting an unstrained, undistorted, life-sized image, and soundstage with massive dynamics and oodles of presence. Its the very reason why easy-to-drive horns and compression drivers do this so easily and with less power. :5:

[Mr Peabody]

Headroom is something you don't hear people talk about much anymore but you are so correct.

[blackraven]

My concern about the Outlaw monoblocks have to do with whether they are truly high current or not. They put out 225wpc at 8ohms and 300wpc at 4ohms. I'm not sure what the dynamic headroom is. I'll have to email outlaw audio for the headroom and amp rating because its not listed in the specs. Magnepans like wattage, high current and lots of headroom. I've also looked at the B&K reference series 200.2 amp. Its rated at 75 amps, 225wpc at 8ohms and 375 wpc at 4ohms. Its a beast of an amp. there are better amps but for magnepans, this amp fits the bill for the price. I don't have the cash right now to drop on a $3,000-5,000 amp.

[O'Shag]

Thanks Mr. Peabody.

BlackRaven, headroom concerns how much power an amp can deliver without any distortion or clipping of the signal waveform and can be observed on an Ocilloscope when an amp is driving a speaker load. Basically a definition of headroom is the amount of reserve power an amp has to deliver on peaks and transients demanding a lot of power without any distortion (these high-demand peaks and transients happen a lot more than many people realize). Delivering a perfectly formed signal to the drivers faithful to the source is much more difficult than it would at first appear. What happens when an amp runs out of headroom as the load increases the signal waveform will distort and then clip when driven beyond its limits.

What is interesting, and what I've observed first hand is the difference more headroom makes, even when one can assume it is not required. For example, a midrange driver and high frequency driver may only require a few watts to operate within stated parameters, and yet how is it that when excessive power is available (even though it is, seemingly, not used) that the drivers actually sound better, with more clarity, less distortion, and a bigger effortlessly produced soundstage, leading to much less strain when the volume is turned up?

Interestingly, I happened across a paper written by one of the leading JBL engineers. You better believe that JBL know what they're talking about. They been building speakers longer than most and I've heard many of their top speakers, including three different Hartsfields, the 4350 studio monitor, the newer Everest, as well as many professional systems. This particular paper was addressed to the many thousands of requests JBL received from enthusiasts all over the world regarding how to build the ultimate speaker system, and they wanted to put the ultimate question of life, the Universe and everything to rest for all these folks. This information was given unofficially, and as a way to get all these people off their backs. You probably know that JBL use horns and compression drivers, which are very, very efficent. Why then, is their ultimate system driven by 600 watt amplifiers - FOR EACH DRIVER!!! And that includes the tweeter! Boggles the mind. Even knowing that flea watt SETs can drive these hyper sensitive drivers to high SPLs that can ruin your hearing, they still choose such powerful amplifiers. The signal is processed by external electronic crossovers which then drive the seperate power amplifiers. What I deduce from this, and what I've heard myself in my own tinkering around, is that the extra power benefits performance.

If you use 2 sets of Outlaw monoblocks in a biamped configuration, you will greatly increase headroom over just the one pair. I suspect your maggies will sing as you've never heard them before - and they are great speakers.

[blackraven]

I understand headroom and what it means. Just look at NAD receivers. Most are moderately powered at 100wpc but can deliver 400wpc instantaneously but not continuously.

[O'Shag]

Yup, NAD is definitely a cut above many of the affordable class of integrated components. I that many manufacturers tend to overstate their power ratings. But NAD would be one of the few I'd be more inclined to believe.

[Mr Peabody]

Current is also important for driver control, this is usually observed by speakers driven with higher current having more punch in the bass and a more powerful sound.

I'm not familiar with either amp but going by the specs, the B&K looks to be a higher current amp. If Maggies have low impedance swings then the current will be more important than the headroom. Amps that have a high current design tend to also have good headroom. I remember many years ago when I worked at a stereo store the Proton rep brought in the D1200 which had "Dynamic Power on Demand" which was capable of producing a big headroom spec. We asked him if it would drive Infinity Kappa 9's which swung extremely low. These were amp killers but we didn't carry any amps really high end. Anyway this guy was so confident, so we strapped the D1200 to the 9's and let it play for a few minutes then the volume went up and the amp soon went silent. I felt sorry for the rep, he was crushed.

I heard Dynaudio has an amp they built at their factory that has such large capacitor banks it can be unplugged and keep playing for a ridiculous amount of time like 24 hours. They sell these amps as well, I can't remember the price. But, how is that for reserve?

[blackraven]

I'm leaning to the B&K for $1200 at discount sites. Reviews on this amp have been very good. Its supposed to be a warmer sounding amp from what I've read. And it certainly is a high current amp with its rating of 75amps. I'm also impressed by the fact that it just about doubles its wpc at 4ohms which is about the best you can get. Very few if any amps actually fully double their power as you drop in ohms.

[O'Shag]

Mr. Peabody, I would definitely agree . Current is critical. I think, generally speaking, the two tend to go hand in hand, but its definitely important that BlackRaven get amps that are high-current given the challenging impedence curves associated with the Maggies. I know that B&K used to and probably do still serve professional recording studios. That itself is a good start. Ultimately, listening is a must. A friend of mine who sells stuff from professional studios as they cycle out old products or go into liquidation recently sold a B&K 300 watt amp with both balanced XLR and single-ended inputs, for $65.00!!

[O'Shag]

BlackRaven, if you like I can check with my friend who deals with the recording and movie studios her in Los Angeles. He cycles out amps from the studios and as I said above he sold a 300 watt B&K amp recently for $65.00. The only downside, is that they come from a prefessional environement, so might have some scratches. Anything he sells though is operationally perfect. He is a very trustworthy chap.

[blackraven]

Thanks O'Shag. That would be great! I come out to LA all the time. My brother lives in Seal Beach and my mother lives in Laguna Hills. I'm coming out there either this month or next.

[Mr Peabody]

Hey O'Shag, feel free to let all of us in on deals like that! I can live with a scratch.

[O'Shag]

No Problem. BlackRaven. By the way, I lived in Minneapolis for almost three years several years ago. I used to work for Unisys out of Eagan Minnesota. St Paul is a great city too. I've attended mass at St. Pauls and also at the Basilica in dowtown Minneapolis. Really had a great time there. I'll check with my mate at the studios and see if he has anything interesting. as for myself, I'm strongly considering some Brystons.

[O'Shag]

Mr. Peabody, I can certainly let you know. But not all of em look too purdy. The professionals don't give a hoot about cleaning the components off with a nice soft cotton cloth. All the components are shoved, not placed into racks. So the scratches can be many. The upside is the amps and stuff they use are built tough. One could always refinish a components exterior if needed. I would have bought lotsa stuff from him, but my better half is not very tolerent of anything that looks 'vintage' or in any way 'used' despite my protestations. Such is life. Sometimes I know how Rumpole of the Bailey must have felt when being bossed around by She Who Must Be Obeyed...

[Mr Peabody]

I read a good review on the Brystons. I recall them mentioning they were surprised that the monoblocks were on the warm side.

All my stuff is down in my man cave, a 300 wpc amp for $65.00 it can look like it had been drug around the parking lot for all I care, as long as it works :)

I don't know if you saw my thread, "trip to the hi fi shop", I heard a pair of Clayton Audio 300 watt, Class A, monoblocks. They were killer. I think they were only $14k. They were driving Dynaudio Sapphires. I don't know which to attribute most but the combo reproduced some tremendous bass response, low and powerful. You couldn't even tell any difference in tone from low to high volume, at high volume, the sound was clean and clear like the amps were on light duty.

[O'Shag]

I did see your thread Mr Peabody, and it is a great report. Those Dynaudio;s look too beautiful. The thousand will be bought up in no time I'm sure. Maybe you could swing a deal with that audio shop. What a triumph that would be...

[Mr Peabody]

Unfortunately, I don't have the means for something like that.

[O'Shag]

You could always sell the car?