Pro Amps I.e. Crown, Qsc

[E-Stat]

I'm missing something here, been a few years since my last physics class. But the relevant unit of application (power) is still watts, no? Regardless of joules.
With a unit of time introduced, wouldn't the number of joules and watts be the same anyway? Ie: 1 joule = 1 watt-sec?

There is no direct relationship with the quantity of watts from an audio amplifier and the stiffness of its power supply. They vary widely indeed. The formula for stored energy is J=CV2 /2 where Joules = Capacitance X Voltage (rail) squared divided by 2. (Sorry I can't get the HTML superscript tag to work). Do the math on some amps you know. Rated wattage is irrelevant. I know of some 100 watt amplfiers with stiffer power supplies than most 500 watt amps.

I liken power supply stiffness to torque. How quickly can you deliver those watts? For most sound reinforcement applications, the question is moot. There is no dynamic range to speak of. While the amps may be cranking out kilowatts, they lack the ability to dynamically jump like the best amplifiers are capable of. It took me years to fully understand what reviewers meant by an amplifier having "authority". It is that utter sense of control and ease at any power level with the ability to literally startle you on wide dynamic range material. As in truly live, unamplified music.

Quality and quantity are not the same.

rw

[kexodusc]

There is no direct relationship with the quantity of watts from an audio amplifier and the stiffness of its power supply. They vary widely indeed. The formula for stored energy is J=CV2 /2 where Joules = Capacitance X Voltage (rail) squared divided by 2. (Sorry I can't get the HTML superscript tag to work). Do the math on some amps you know. Rated wattage is irrelevant. I know of some 100 watt amplfiers with stiffer power supplies than most 500 watt amps.

I liken power supply stiffness to torque. How quickly can you deliver those watts? For most sound reinforcement applications, the question is moot. There is no dynamic range to speak of. While the amps may be cranking out kilowatts, they lack the ability to dynamically jump like the best amplifiers are capable of. It took me years to fully understand what reviewers meant by an amplifier having "authority". It is that utter sense of control and ease at any power level with the ability to literally startle you on wide dynamic range material. As in truly live, unamplified music.

Quality and quantity are not the same.

rw

I'm afraid my experience with pro-amps is far different than yours. If anything I find them every bit as dynamic, if not more than "audiophile" amplifiers. But to be fair, I I would suspect if you were to push a Bryston or Krell to their limits for sound reinforcement, they'd behave similarly. If you start to loose dynamics, that tells me you need a bigger amplifier. I'll admit I'm not an expert in this area though...I'll have to go crack open a physics textbook or two...as I said, it's been awhile for me.
I also don't understand your torque analogy. The "quick" element of delivering watts doesn't jive here. How long should it take? How long does it typically take? Is it really distinguishable?

Those kilowatt pro-amps do have fantastically huge power supplies. Larger than most big watt hi-end amps I'm aware of (though I expect there's some exception). I dunno...to me it seems pairing an amplifier with a PSU that can meet the expected demands placed on it with perhaps a bit of headroom would be sufficient. Beyond THAT, it becomes moot, with no additional advantage.

[E-Stat]

I'm afraid my experience with pro-amps is far different than yours. If anything I find them every bit as dynamic, if not more than "audiophile" amplifiers. But to be fair, I I would suspect if you were to push a Bryston or Krell to their limits for sound reinforcement, they'd behave similarly. If you start to loose dynamics, that tells me you need a bigger amplifier.

You're still talking in quantitative terms. I'm not talking about clipping characteristics.

The "quick" element of delivering watts doesn't jive here. How long should it take? How long does it typically take? Is it really distinguishable?

Play something with explosive dynamics like Orffs "Carmina Burana" or Stravinsky's "Rite of Spring" to illustrate my point.

Those kilowatt pro-amps do have fantastically huge power supplies. Larger than most big watt hi-end amps I'm aware of (though I expect there's some exception).

So, my question remains. You keep saying they're "fantastically huge". How huge? The metric for judging that parameter is joules. The big brother to my amps, the Siegfried, has 780 joules. The Passlabs X1000 has 700 joules. The Audio Research Ref 610T has 1000 joules. Crack open a case and look at the total capacitance and find out the rail voltage.
(edit) I couldn't find schematics for current Crown amps, but the CT800 amp with 305 watts /channel stereo runs 12,600 uf @ 87 volts. That yields 24 joules.

I dunno...to me it seems pairing an amplifier with a PSU that can meet the expected demands placed on it...

But most cannot on an instantaneous basis when the source material is wide range unamplified music. Here again, sound reinforcement applications are undemanding in that regard.

rw

[pelly3s]

well i will just put it this way about about this whole thing, take almost any home amp and tell me if you have enough current to power an MRI machine. I would highly doubt it, also how many will give you over 7,000 watts per channel at a half an ohm constantly. And even getting away from the beast of an amp that a 10,000 is, if pro amps have small power supplies how is it they can deliever massive amounts of wattage and current. Lately the answer is a switching supply but before it was just a huge transformer. I will challenge home amps against a macro tech 5000 and see what the winner would be when it comes to longer term high power conditions and which one delivers more current. lets see how many home amps can drive my double 18 boxes to there limit without going to hell.

as for dynamics, i do a lot of live music with a huge amount of dynamics so i dont see where the lack of dynamics is in live music.

[E-Stat]

I would highly doubt it, also how many will give you over 7,000 watts per channel at a half an ohm constantly.

Indeed. It's a Mack truck.

And even getting away from the beast of an amp that a 10,000 is, if pro amps have small power supplies how is it they can deliever massive amounts of wattage and current.

Neither of your two original examples are like that discontinued amp. When you read the spec sheet for the 10000, however, you quickly see that the power figures are stated only for a "single cycle tone burst at 1 khz". Running Class B at that. Certainly not intended for serious listening. For a given power output, the best home amplifiers have far larger power supplies as I indicated in my last post. Like a factor of 20.

Lately the answer is a switching supply but before it was just a huge transformer. I will challenge home amps against a macro tech 5000 and see what the winner would be when it comes to longer term high power conditions and which one delivers more current. lets see how many home amps can drive my double 18 boxes to there limit without going to hell.

Perfect analysis of the very different design criteria between amps designed for sound reinforcement and those intended for the highest quality music reproduction. Who cares how many bins an amp can drive when you use a single pair? Similarly, sustained high power capability is irrelevant when the musical content consists of wide dynamics. Each type of amp is specialized for a different task. Pro amps are like pickups. A GMC 2500 can pull a big boat all day long. Attempting that in a Porsche would smoke the clutch in short order. The GMC, however, has no hope of accelerating or cornering in the same league as the Porsche. I found a schematic for this amp on the Crown site. It uses four 15,000 uf caps rated at 110 volts. Assuming some design reserve, it would store 300 joules if the rails were at 100 volts, or 230 at 90 volts.

as for dynamics, i do a lot of live music with a huge amount of dynamics so i dont see where the lack of dynamics is in live music.

My point was that the type of music with the widest dynamics is that which uses no amplifiers at all. Fortunately when I go to the symphony, I don't find stacks of horns and piezos driven by multi-kilowatt amp banks.

Returing to the original question, pro amps can be quite cost effective in an HT system. I just wouldn't use one in a high quality music system.

rw

[kexodusc]

You're still talking in quantitative terms. I'm not talking about clipping characteristics.

Neither am I...and if I'm talking in quantitative terms, it's only because I'm trying to understand and verify your claims, not avoid the issue. Qualitative isn't enough, there must be a reason for the qualitative results, and this should be quantifiable. You used the word "quick" or "quickly" earlier, which implies speed, a measurable quantitiy. Are we talking about slew rate here or something else?

I'm having a difficult time here learning what you're saying here, and I'm hoping you can step me through this a bit better as you seem to know a bit more than I, this is the first time I've ever heard someone claim pro-amps lack the dynamics that hi-fi amps might have. I'd like to explore this, learn why this is true, but I'm unable to verify what you're telling me so far...hoping you can help...

The metric for judging that parameter is joules. The big brother to my amps, the Siegfried, has 780 joules. The Passlabs X1000 has 700 joules. The Audio Research Ref 610T has 1000 joules. Crack open a case and look at the total capacitance and find out the rail voltage.
(edit) I couldn't find schematics for current Crown amps, but the CT800 amp with 305 watts /channel stereo runs 12,600 uf @ 87 volts. That yields 24 joules.

I've found a Crown amp and a big bad Krell I can do this for, hopefully before I go away this weekend. Not doubting your claims here, I suspect this could be a revelation of sorts.
Quick question...how did you arrive at 24 joules in the above example?
Assuming the figures you give me are correct, step by step I get (.0126 F X 87V X 87V)/ 2 = 47.6 or so...we're off by about a factor of two. Again, I think I'm overlooking something.

But most cannot on an instantaneous basis when the source material is wide range unamplified music. Here again, sound reinforcement applications are undemanding in that regard.

Okay, this is where I have the issue. What you're saying and the numbers we can crunch together aren't jiving with what I'm hearing. Let's look at a Crown XLS 602, which I recently got to play with. 370 watt "average power" (not RMS). It performed quite well beside a Bryston 4B (a reasonably well respected unit). DG's Carmina Burana was in fact one of the reference discs used (Beethoven's 5th on SACD another).

The speakers used wereof average efficiency, about 88 dB., 4ohm nominal speakers, from the Seas Excel line. These aren't 2nd rate by any means.
We cranked these things up to the high 90 dB range the odd peaks measured (a weighted only on the SPL meter we had) above 100 dB in room.
Neither of these amps had any problem pushing these speakers at all. I can't say either amp was any better at producing the dynamics, the sound from the speakers was so good in both cases that it was hard to pick a winner. I'd give the slight sonic refinement edge to the Bryston, it's impossible for me to accept it was $2200 dollars better than the Crown.

And here I think is where the crux of the matter lies. Show me an amp for $500-600 with as big a power supply, as much real power available, for the $575 pricetag on the Crown, and I'll be happy. Yes, I'll concede that sooner or later the market will become more discriminating, and you'll be forced to look at the likes of Krell, Levinson etc..
But in the $1000 and below range, I think pro-amps hold their own quite nicely in terms of power and sound quality. Though I'd love some suggestions if you have any, I expect to be in the market for some new amps quite soon.

[E-Stat]

Are we talking about slew rate here or something else?

Don't think so. It may show up, however, in tone bursts.

I'm having a difficult time here learning what you're saying here, and I'm hoping you can step me through this a bit better as you seem to know a bit more than I, this is the first time I've ever heard someone claim pro-amps lack the dynamics that hi-fi amps might have.

Well, strictly speaking, dynamic range is the difference between the minimum and maximum levels. There is no notion of how forcefully that is achieved nor the relative levels. And fans don't help with low noise floors. Especially when a good aftermarket PC is used which can further reduce the low level haze. As my gear has gotten better, I end up listening at reduced levels and still get satisfying loud in the room.

I've found a Crown amp and a big bad Krell I can do this for, hopefully before I go away this weekend. Not doubting your claims here, I suspect this could be a revelation of sorts.

Have fun.

Quick question...how did you arrive at 24 joules in the above example? ... Again, I think I'm overlooking something.

Nope, I musta done the division by two twice. You are correct.

Okay, this is where I have the issue. What you're saying and the numbers we can crunch together aren't jiving with what I'm hearing...Neither of these amps had any problem pushing these speakers at all.

"Pushing" the speakers is not what I'm referring to. Here's a totally unscientific measure: the ability to downright startle you or raise the hairs on your arms like the real thing. Last fall, the ASO did the Carmina Burana again and the wife and I were in row C. That piece contains explosive dynamics.

I'd give the slight sonic refinement edge to the Bryston, it's impossible for me to accept it was $2200 dollars better than the Crown.

I only speak in performance absolutes and don't disagree that there is a decided premium to achieve what I am referring to. BTW, the Wotans will knock your socks off with three dimensional realism, focus, and SLAM.

And here I think is where the crux of the matter lies. Show me an amp for $500-600 with as big a power supply, as much real power available, for the $575 pricetag on the Crown, and I'll be happy. Yes, I'll concede that sooner or later the market will become more discriminating, and you'll be forced to look at the likes of Krell, Levinson etc..
But in the $1000 and below range, I think pro-amps hold their own quite nicely in terms of power and sound quality. Though I'd love some suggestions if you have any, I expect to be in the market for some new amps quite soon.

Agree with you completely. As for considerations for your next amp, I might try a used Threshold Stasis or Passlabs X150 with a good power cord. Nelson Pass has birthed many a fine amplfier over the past thirty years. His current Passlabs amps are killer SS units. The larger ones use no less than 250,000 uf of capacitance.

I've never favored the Krells very much, but then I haven't heard their best examples. Harry Pearson used to run KMA-160 monoblocks on his Nola woofers a few years ago.

rw

[mixadude]

Live audio has much wider dynamic range than any recording, and much higher spl requirements without failure. Recording is, after all, something that was live sound, either acoustic or electronic, then almost always compressed at least some when mastered. I could blow up most hifis with just a drum sound check, even megabuck ones.

Joules only really matter to old dinosaur type power supplies; new switchers and hi tech pro amps have supplies that can vary available supply current faster than the audio demand, let's face it folks, audio isn't all that fast as far as modern electronics capabilities go here in the gigahertz era.

I do agree that different amps certainly do sound different though. The pro ones certainly do. Those Crown MacroTech amps are sweet, but heavy. I'm sure that hifi amps all sound different, too. That's why yas gotta listen to them, preferably in your own system, to find hifi nirvana.

[nightflier]

Here's a totally unscientific measure: the ability to downright startle you or raise the hairs on your arms like the real thing. Last fall, the ASO did the Carmina Burana again and the wife and I were in row C. That piece contains explosive dynamics... I only speak in performance absolutes and don't disagree that there is a decided premium to achieve what I am referring to. BTW, the Wotans will knock your socks off with three dimensional realism, focus, and SLAM.

E.,

OK, I've been reading all this with great interest. I have several amps and speakers on hand that I can swap out for this. I also have several different recordings of Orff and Stravinsky's, as well as other dynamically explosive selections (Mahler's 5th and and Hovhaness' Mount Wildcat come to mind) and have heard Carmina and Rite of Spring live several times. But to keep things simple, let's stick to Carmina since most people here will know and own that one. I'm not interested in unscientific measures which could easily be influenced by other environmental and psychological factors. What I have observed in the past with different amps in the under $2K price range are small differences that one could almost classify as "preferrences" rather than true measures of capability. That said, I am very interested in hearing what you are referring to in the above discussion about Joules and explosive dynamics.

So, in Carmina, what exactly am I listening for?

[E-Stat]

That said, I am very interested in hearing what you are referring to in the above discussion about Joules and explosive dynamics.

So, in Carmina, what exactly am I listening for?

My reference is the 1981 Telarc version with the ASO and Chorus. I confess bias to this version because my long term friend, mentor, and ex-TAS reviewer JWC has been a bass in the chorus for thirty years.

There are two sets of passages that exhibit huge contrasts, both containing steep initial attacks and abrupt returns to silence. Using Sound Forge as a visual guide, even my Telarc Rite of Spring does not contain such massive swings. The first one is about six minutes into In Taverna. The chorus refrain of Wafna, wafna! will knock you off your seat live.

Here is a Sound Forge representation:


The last minute or so is worth hearing as well. The second passage is found in the last couple of minutes at the end of Fortune No.25. Again, the impact is heightened by the return to silence. Here again is Sound Forge:



Here's another one just for grins. This rates at least two pampers on the HP scale. It is fromYim Hok-Man's Marco Polo recording of Chinese drum music.



Hearing this on the Grand Exoticas is a joy to behold.

Enjoy your comparisons!

rw

[kexodusc]

My reference is the 1981 Telarc version with the ASO and Chorus. I confess bias to this version because my long term friend, mentor, and ex-TAS reviewer JWC has been a bass in the chorus for thirty years.

Ahh, the ASO...Probably what I miss most about Atlanta...I no doubt have had the priviledge of witnessing your friend perform.

[nightflier]

E.,

OK, I don't have the 1981 Telarc, but I do have a couple of others, including the Donald Runnicles/Atlanta Symphony Orchestra SACD, so that should do. Now, I know the passages well, a short section of In Taverna is actually on one of my home-made eval CD's that I bring to the stores to audition stuff.

So what would be some of obvious the differences between a high-joule amp and a lesser one? I did a quick pass last night with the finale ('cause it's nice & short) comparing my HCA-2 amps against an obviously less powerfull unit, a NAD C320BEE integrated. While there are differences, I'm not sure what was listening for, last night.

[E-Stat]

Ahh, the ASO...Probably what I miss most about Atlanta...I no doubt have had the priviledge of witnessing your friend perform.

And then you journeyed to Parts Unknown. How is the weather this time of year in PU?

rw

[kexodusc]

And then you journeyed to Parts Unknown. How is the weather this time of year in PU?

rw

Err...yeah, I really should update that now that I know where I am...

Getting damn cold fast. NB, Canada is a long way away from Georgia...in soooo many ways. Not all of them bad.

[E-Stat]

So what would be some of obvious the differences between a high-joule amp and a lesser one? I did a quick pass last night with the finale ('cause it's nice & short) comparing my HCA-2 amps against an obviously less powerfull unit, a NAD C320BEE integrated. While there are differences, I'm not sure what was listening for, last night.

First of all, the differences may fairly be considered subtle, not "obvious" to all. That depends upon your passion for getting the music right. I've come to learn that the best path to achieving wide dynamic range is to plumb the depths, not the height of the scale. Keep the peak levels matched as best you can. Here are real questions: (1) which amp takes you down further in level with content? and (2) which amp is more at ease whilst delivering a FFF crescendo? The most powerful passages should ultimately be rendered with absolute control and grace. While Class T switching amps run digitally, the Audio Research 105.2, for example, still has 144,000 uf of capacitance in its powr supply. The need for power supply stiffness is not limited to conventional class A or class AB amps.

It is here where better cables of all sorts can help achieve a "blacker" background. There is missing detail to be found in most systems, not from the top, but from the bottom of the dynamic scale. Which when salvaged, increases the overall range. Such higher resolution systems remove a somewhat tinny "haze" over the entire image - resulting in a sound that initially seems darker and somehow rolled off. What's missing is not more detailed musical content, but a subtle glare cast over the music. The highs become better defined and more delicate once that mist has been lifted.

rw

[E-Stat]

Getting damn cold fast. NB, Canada is a long way away from Georgia...in soooo many ways. Not all of them bad.

I'm sad to say I've never traveled to New Brunswick (my wife has once). All my other trips to Canada, however, have been quite enjoyable. I've been to Ontario and Alberta - but not NB nor BC. Sometime, I need to consult RGA about Vancouver.

Last month I hiked Glacier Park in Montana and crossed the border and visited Waterton Park. Climbed Bear's Hump. Gorgeous.




rw

[theaudiohobby]

E-stat, your last post omitted a smaller matter called efficiency, The audio research NEEDS a larger capacitive storage because of much larger losses both in the PSU and amplification stages. The two approaches are an antithesis of each other, one uses brute force and other is much more nimble (efficient).

[nightflier]

"...The most powerful passages should ultimately be rendered with absolute control and grace..."

I hear the word "control" a lot in reviews, but I'm not sure I'm getting it. I'm not sitting in front of my speakers right now, so I can't verify what I'm describing, but I don't think either the HCA-2 or the NAD have trouble with control. The HCA-2 has noticeably deeper, more powerfull bass, but coming up the scale, both amps seem to be able to do quite well above ~100Hz. or so. Even with sudden FF passages.

"...can help achieve a "blacker" background."

Colors have always confused me. I realize that to express music in words is difficult, but what do you mean by "blacker" ?

"There is missing detail to be found in most systems, not from the top, but from the bottom of the dynamic scale. Which when salvaged, increases the overall range."

I'm going to go out on a limb here and suggest a correction. If there is missing material as a result of the system, it should be missing all across the scale. Aren't we simply saying that our ears are not as capable of discerning the missing material in the upper frequencies - but that it is still missing? True, some equipment will be able to play lower bass, but I don't think that is what we are referring to here, in the discussion of explossive dynamics. In short, to come up from a lower frequency will be more apparent, but that says nothing about the manner in which said amp climbs up the scale. This is what I think we are talking about with "control," but I am having a hard time hearing it.

"Such higher resolution systems remove a somewhat tinny "haze" over the entire image - resulting in a sound that initially seems darker and somehow rolled off."

Now I'm confused again. I don't hear any "haze," although I do hear that the NAD is warmer by a tad. It seems less crisp and less detailed.

I'm not trying to beat a dead horse here, but I am really trying to quantify some of these things I'm supposed to be hearing. The HCA-2 should be vastly superior to the the NAD, especially considering the differences in rated specs, but I haven't found vast differences, and I have usually used other terms to describe them.

Has anyone else done some side-by-side testing of two amps after reading this discussion? I suppose a side-by-side test of a pro audio amp and a home audio amp, would be appropriate here.

[E-Stat]

I hear the word "control" a lot in reviews, but I'm not sure I'm getting it. I'm not sitting in front of my speakers right now, so I can't verify what I'm describing, but I don't think either the HCA-2 or the NAD have trouble with control.

Everything is relative. The differences may not be significant between those two units.

"...can help achieve a "blacker" background." Colors have always confused me. I realize that to express music in words is difficult, but what do you mean by "blacker" ?

A lower noise floor, especially evident at the lowest levels. At first blush, everything sounds somewhat darker or rolled off.

I'm going to go out on a limb here and suggest a correction. If there is missing material as a result of the system, it should be missing all across the scale. Aren't we simply saying that our ears are not as capable of discerning the missing material in the upper frequencies - but that it is still missing?

I am referring to a masking effect where musical detail is lost or blurred in the relative noise floor.

In short, to come up from a lower frequency will be more apparent, but that says nothing about the manner in which said amp climbs up the scale. This is what I think we are talking about with "control," but I am having a hard time hearing it.

The control or authority I refer to is not really a frequency specific sort of thing. An authoritative amp exhibits an utter sense of ease in the upper octaves as well as the lower ones. I too, find it difficult to sense without a point of comparison. The first amp I heard demonstrate that quality was a C-J Premier One back in 1980. I was recently rereading a TAS from 1978 for JWC's report on the first Telarc Recording. As I was thumbing through it, I also found a review of the Dynaco ST-416 amp and C-100 storage box. Following the lead by long term Dyna modifier Frank Van Alstine, Dynaco offered an outboard box containing an additional 100,000 uf of capacitance. The review compared the amp without and with one, two, or three of the C-100s. They opined that one was a definite improvement, two seemed to help at the highest levels, but three was no better than two.

Now I'm confused again. I don't hear any "haze," although I do hear that the NAD is warmer by a tad. It seems less crisp and less detailed.

Here I'm referring to the benefits offered by aftermarket power cords or power regenerators. Recently, I bought some Harmonic Technology power cords for the monoblocks in the main system and moved the existing cords to my vintage music system and to the HT. In the vintage system, I am hearing a darker, clearer presentation rendered with more subtle detail. Imagine two pictures, one that contains a bit of glare from the sun and the other not. The details of the one containing glare are less well defined while the other photo is crystal clear.

The HCA-2 should be vastly superior to the the NAD, especially considering the differences in rated specs, but I haven't found vast differences, and I have usually used other terms to describe them.

Well, "vast differences" are not what you are likely to find between those two amps. Other than power, I've yet to draw any direct correlations to quality musical reproduction and rated specs that are alleged to draw qualitative distinctions such as THD.

rw

[pelly3s]

i read the word blacker and the only thing that comes to mind is spinal tap with their black album in which there is "none more black"

[BRANDONH]

Very nice indeed. Now where else are you going to find a 1100W amp with 0.05% THD? A friend of mine is about to spend $2500 on a stereo amp. I can't wait to tell him about this one.

Now, the real question: how does the consumer market get away with charging at least twice as much for all their amps? I'm starting to feel a little jilted myself for all the amps I've bought (and sold) over the last decade...

Well I just decided to get another so I can bridge them.
That will be 4800 watts at 8 ohms.
QSC has decided not to sell the reference quality amplifier anymore.
I picked up the second one brand new for $1300.00 not a cheap as the first one I got from Musicans Friend when they had them for 799.99 but still less than than the 2499.00 they retailed for.
The guy I bought it from has only six new ones left so if any of you are interested I can give you his phone number by private message.
He mostly sells pro equipment for commercial customers but can sell to the general public as well.

[BRANDONH]

Well I just decided to get another so I can bridge them.
That will be 4800 watts at 8 ohms.
QSC has decided not to sell the reference quality amplifier anymore.
I picked up the second one brand new for $1300.00 not a cheap as the first one I got from Musicans Friend when they had them for 799.99 but still less than than the 2499.00 they retailed for.
The guy I bought it from has only six new ones left so if any of you are interested I can give you his phone number by private message.
He mostly sells pro equipment for commercial customers but can sell to the general public as well.

Is no one intrested in getting one of these while supplies last?

[jneutron]

An interesting thread..what is a joule???

E-stat...everybody knows power cords don't make a difference..why do you continue to say this..just buy some (more) vanilla cords...


I would be concerned with several things with respect to the total energy storage of the supply bank..

1. How much droop occurs during heavy loads, and how this droop level makes it's way back into the electronics..output stage gain modulating (hfe vs Vce down neat Vce(sat), modulation of the damping factor in all four output quadrants.

2. How the input circuit re-charges this drain, both haversinewise and conductivity coupled cap draw back through the bridges.

3. For smps setups, are they two stage with PFC, or single stage..at least the PFC has spare energy to feed in during line zero crossings. (single phase systems).

4. The hf capacitance characteristics of the supply caps and loop coupling from the output draw back to the xfmr and out the line cord..geometry based, of course..a larger bank of capacitors makes the loop coupling less as a result of spreading the full current out among more spacial volume, thereby reducing the loop coupling to nearby circuits.

5. How inadequate the star grounding scheme is for large, hf current draws into low impedance loads.


Me, I just play with my rmx 1450..so far, it has served me well..but my applications have the amp over 35 feet from the front row of audience..about 100 feet from me (when I am hovering over the summer hired school kid who runs the sound and lights.) So I am unconcerned with fan noise.

Cheers, John

[E-Stat]

An interesting thread..what is a joule???

That reminds me of the classic line delivered by actor Fred Gwynne (Herman Munster) as judge in the movie "My Cousin Vinnie". After Joe Pesci as defense lawyer talks about "youths", Fred asks "What's a yute?"

A joule is a unit of energy or work named after nineteenth century physicist Jimmy Joule.

E-stat...everybody knows power cords don't make a difference..why do you continue to say this..just buy some (more) vanilla cords...

You know those crazy audiophiles and their shared mass hysteria.

I would be concerned with several things with respect to the total energy storage of the supply bank..

I'll leave the details to you. I just know I like 'em really big to provide better dynamics and slam. The two best sounding amps in my experience, the VTL Wotan and the ASR Emitter II Exclusive have such. The power supply of each mono Wotan stores 780 joules. While I'm not sure of the joule rating for the ASR, it possesses 1.2 farads of capacitance (400,000 uF of which is used in the battery supply for the input stage).

rw

[jneutron]

That reminds me of the classic line delivered by actor Fred Gwynne (Herman Munster) as judge in the movie "My Cousin Vinnie". After Joe Pesci as defense lawyer talks about "youths", Fred asks "What's a yute?"
rw

That was a good line..I really enjoyed Fred in that one..

A joule is a unit of energy or work named after nineteenth century physicist Jimmy Joule.
rw

I thought it was named after his brother "Crown"..or his father "Family".

We just shipped out a magnet for use in a facility on site, we had to test it and make it use less liquid, it stored 1.5 megajoules. But it was inductive storage, so didn't have the "slam" my 6 kiloamp diode pulser had..

You know those crazy audiophiles and their shared mass hysteria.
rw

Yah, we should take em out the back and shoot em..or at least make em listen to inna gadda da vita on headphones..

I'll leave the details to you. I just know I like 'em really big to provide better dynamics and slam. The two best sounding amps in my experience, the VTL Wotan and the ASR Emitter II Exclusive have such. The power supply of each mono Wotan stores 780 joules. While I'm not sure of the joule rating for the ASR, it possesses 1.2 farads of capacitance (400,000 uF of which is used in the battery supply for the input stage).

rw

Crazy audiophiles one and all..it'd be so much more elegant to pull the v feedback off the speaker terminals using a quadaxial setup of the type I had sent to Ted. Too bad he never returned them to me..

Oh well, live and learn..It'll be interesting to find my design on someone's product in the near future..with no credit for da tinkin part of it..

Man, I love this jpeg capability..nothin like a pic..here's that cap bank. uses copper buss cause it's 6 kiloamps. 32 capacitors, 2000 uf apiece, 400 volts give or take..5,120 joules..I'm glad I only deal with the small stuff, the big stuff scares me..

Cheers, John