Bob Carver said what!?

HBombToo

In an Interview with Bob Carver the following question and answer I copied for brevity.

GB: How audible are the differences between solid-state amplifiers?

BC: What I'm going to say will fly in the face of what most people believe. I believe that you can take two solid-state amplifiers, and provided neither one is overloaded in any fashion, they'll sound identical. That's a big if. Amplifiers are overloaded in three basic ways. They're overloaded in amplitude; they've overloaded in current; they're overloaded in speed. It's very easy to do this if you don't have a big juicy amplifier. Obviously a little Radio Shack amplifier is not going to be able to touch a big Jeff Rowland or a Mark Levinson or a Sunfire amplifier. Provided the amplifier has flat frequency response and sufficiently low distortion, both of which are trivial these days, and provided there are no interface problems, the differences will always be the subtle differences associated with overload, either momentarily, like slew-rate limiting or clipping, or just running out of drive current.

Here is the link for reverence.
http://www.audio-ideas.com/interview/carver.html


WOW!

trubluluc

I guess when one reaches a certain point in awareness, hyperbole ceases to exist.


-Luc

HBombToo

or perhaps a very pragmatic approach?

RuSsMaN

I wise man once told me, 'Around a dollar per watt is a good price for an amp'.

I believe this through and through. I love my Carver's - m400a (201 wpc continuous), m200t (100 wpc continuous). Look at the deals other members got, RonP and his Adcoms, Mantis and Phuz with their Rotels. Around a dollar a watt.

I'm not saying there is *ZERO* difference, but these are all GREAT amps, that I feel can hold there own with the best of the best, in a double blind scenario if given the chance (and all other components equal).

For me, the magic in electronics (tonal difference) is in the sources (dacs), and preamps. For example, to me a Yammie amp isn't harsh/bright, it's the input stage in the Yammie pre that puts that 'tonal signature' on it. (Some like it, some don't, no offense to Yammie owners). In my limited experience, I've noticed the most difference in INPUT stages on pres, vs OUTPUT stages on amps. It's all voltage in amps, for the most part - power from the wall, to your speakers.

I'll even say interconns, and speaker wire (to a degree) will make a larger tonal 'shift' moreso than switching amps (solid state) with good, high current and ample headroom.

For me, speakers are where the REAL fun is at. Nail down a good amp, abiding by the $ rule above, and look to the networks, driver / cab designs in loudspeakers for changes in sound. As I said, pre's and sources can be a boatload of fun too.

Cheers,
Rooster

hoosier21

For a guy who sells high end $$ amps that is a pretty bold statement.

HBombToo

Originally posted by RuSsMaN

For me, the magic in electronics (tonal difference) is in the sources (dacs), and preamps.

The more I look into this stuff the more I agree with this statement. Digital Processing,(D---->A), is very important in what we percieve.

I have ta say a very interesting read though!

HBomb

mantis

Intresting read.....I'll give it that.

burdette

I don't think it is that surprising, especially with the state of electronics today. Perhaps not surprising coming from me, given that I don't buy into things like esoteric cables, etc. I doubt anyone reading these forums could tell the difference between a $200 receiver vs. a very expensive set of separates, playing through the same speakers, at reasonable levels, using the same source - as Carver says.. assuming the receiver isn't clipping or in some other way distorting.

It is when the systems are pushed.. high volume, feeding high current speakers, heat production, etc, that the more expensive components may have the advantage. And of course, as has been mentioned, more expensive components may have more expensive parts in other stages of the chain, leading more to any perceived differences than the amplifier stages themselves.

F1nut

Carver is a refreshing voice at times.

mantis

burdette,
I couldn't dissagree with you anymore.

receiver's and seperates don't sound the same at any level....I don't buy the amp sounds the same...........I think Bob Carver has done wonderfull things for our field..........but I don't agree with everything he says.......this being one of them.

RuSsMaN

Ok, just a quick poll, with all the 'experience' floating around here, who has built what amps?

Cheers,
Rooster

Yes F1, very refreshing.

mantis

building????I'd say less then 1%.....I'm one of the 99%or more who has not.....but,
listening is a different story......

So check this out......take a Yamaha,Denon Pioneer Elite,Sony,Kenwood,Carver,Rotel,Krell,MacIntosh,Classe,run them with any pair of speakers you choose,use any wire you want ,listen to all of them playing at a non clipping,distorted level and tell my they all sound the same..........

here's a better one.....take a preamp/cables/speakers/etc.......just swap out the amps 5 or six time with different brands......again same light listening levels,don't drive them hard.........and tell me you can't hear any difference between them........I can't buy that........I've heard differences from all kinds of different amps.......like why would you want to add a amp to a receiver if all solid state amps sound the same.......If you never drive the receiver out of it's ability to perform it's duties,it should sound like any other receiver........same with amps.....do they........????Come on......I can see maybe if there was perfect inviroments.......but this is the realy real world and things sound different then one another......

Like I said Bob has done great things.......alot of his products are awesome........I wouldn't say the be all end all, but very nice non the less....

RuSsMaN

Let me know when you've participated in a double-blind test on amps, all other components equal. Then we can talk.

I think this is what BC was getting at, I have done it, but not to any degree I would hold as 'truth'. Subjectiveness comes into play (as always in this fine hobby we have, our ears are far from alike), what you hear, what I hear, what Joe 6 pack hears.

But, to end the discussion for now, do you have any hard data that will show Bob's theory does not hold true? I don't. I simply do not have enough experience, or exposure to disprove, or prove otherwise. What was said makes perfect sense to me, in a (vague) nutshell.

Cheers,
Rooster

mantis

double blind test???

dude I have done hundreds of shootouts with amps/receivers with the same song/speakers/wire/room/surge/etc......I hear a difference between them all.There are some that sound close but not exact....there is always something different about the 2 3 4 5 6 7 8 9 amps you listen 2.same pre amp.....I can't even follow this post.......I don't get it

Thats just me.......I'm sure you have heard something that was different.....I also know you wouldn't own what you own if they all sounded the same......different built qulaity,different outputs,different binding posts and wire on the inside of the amp.........I just don't get this post or the point your trying to make dude.........I all for listening..........tell me some of your past shootout's like the one with the texas/polk thing you did....can you tell me everyones amps sound exactly the same on any one pair of speakers that where in that room????think about it.....I really want to know your thoughts on this topic....

shack

Very interesting but still only one man's theory. Granted a very innovative man but still it is just his reasoned opinion. He is obviously not without his supporters and detractors as this opening excerpt from the article we are discussing.

Few figures have engendered more controversy among audiophiles than Bob Carver. Virtually every product he developed at Carver Corporation, which he founded in 1978, contained an unusual feature with an impressive-sounding name. Supporters hailed these features as important innovations. Detractors dismissed them as gimmicks.

It would be intersting to see what other highly respected people in the industry think along these lines. (John Curl of Mark Levenson and Parasound, Paul Mcgowan of PS Audio or Dan D'Agostino of Krell come to mind).

I certainly don't have the expertise to prove or disprove what he says but I tend to be a little skeptical. Maybe this theory could be correct in it's purest form with everything being infiitely equal but that is not real world. Experts can have differing opinions on very complex and technical issues. I bet Matt Polk and Amar Bose have a few different views about speakers (and may agree on some stuff).

As I stated, a very intersting article but my limited real world observations find that SS amps are different and I would expect them to be so.

joe6pak

Hey Russ.

You misspelled my name in your last post.

To all.

In reference to the $200 receiver vs seperates sounding the same I will have to disagree. I just did a receiver vs seperates in home comparison recently. Denon 3802 vs Krell Showcase processor & amp. Used the same speakers, wires & source. I did this at low, moderate, & high volume levels. There is a difference. The big difference with the Krell is in the detail. You hear things that were not there or did not stand out with the Denon. Of course there were other differences such as soundstage, image etc. Even the causual listener, Mrs 6pak, commented that everything sounded so much more clear. She is not really interested in all this stuff and in fact she thinks I am a semi-moron for buying these things. For her to notice the difference, now that is something.

I am not knocking the Denon. It is a very nice receiver and this was not really a fair test. The Krell stuff is msrp $ a lot more the Denon. It should sound better. If it is worth the extra money, now that is up to the individual consumer. I will say that every time I turn on this system I am very pleased.

BTW. This was not a double blind test. I am planning a double blind drunk test this weekend. The double blind drunk test is not as scientific, but it is lot more fun.

joe

RuSsMaN

Sorry about that Joe, where ya been anyway?

I simply feel that all other things equal, changing out amps (of any quality) will be subtle at best (make the LEAST change). No receivers in this debate Joe.

Dan, have you participated in a double blind test or not? I've done 'shootouts', not hundreds, but more than a couple. Seeing and hearing, and hearing only are 2 different beasts all together. If you haven't done it, read up on it, and try it for fun, that's all I'm suggesting. Do it with amps, wires, whatever. I find it interesting what we humans actually perceive, and what we *think* we perceive.

Cheers,
Russ

burdette

Mantis and everyone... I had no doubt some people would disagree with me... otherwise the market wouldn't be supporting very expensive audio/video. I just happen to believe with audio, (as with cars, by the way) once you reach a certain level, *the average listener* at reasonable volume levels isn't going to hear or care about any possible - most likely inaudible - differences. I stand by my statements, as I know you stand by your disagreement.

As for home building amps... when I was working as a EE at a universtiy space physics program, one of the design engineers (I went through engineering school with him) designed and built ALL of his system except the source components. I know he paid $1500 *per tweeter* for the speakers he made, each channel had at least four 15" woofers in a cabinet that was about 6' tall, and his crossovers were fully active. He also designed and built the power/pre-amps because he was not satisfied with anything available for sale. This guy didn't have ANY system in his car because the environment didn't allow for an accurate enough sound... nothing was better than "perfect." While I worked with him, he built this system in his basement. He had to move not too long after... too many complaints from neighbors.

Those sorts of standards are beyond my ability to reasonably comprehend.. but then again, if I had his skill and money (as well as access to a university space physics lab full of top-notch testing and fabrication equipment), I'd probably be building, at the least, my speaker systems. I didn't have the dough to take advantage of my situation at the time. The only thing I have to show for the experience are the banana plugs at the end of my main-speaker wire.

joe6pak

Russ.

I was just ragging you about the spelling.

Where have I been? I have not had time to post much, just reading all these posts seems to take more time than I need to spend here.

I commented on receivers here because burdette said he doubted anyone reading this could tell the difference between a $200 receiver and high end seperates.

joe

burdette

"I commented on receivers here because burdette said he doubted anyone reading this could tell the difference between a $200 receiver and high end seperates."

Take it in context.. I made that statement with the assumptions of the same speakers, and the receiver not driven to distortion, i.e. playing at a reasonble home listening level.

HBombToo

If we are not talking about DAC in the receivers and only the amplifiers I will agree fully withya Burdette. With that being said, if we are not overdriveing the amps then they should sound the same applying all of Carvers assumptions.

IMO of course.

HBomb

madmax

Originally posted by RuSsMaN
I simply feel that all other things equal, changing out amps (of any quality) will be subtle at best (make the LEAST change). No receivers in this debate Joe.

Cheers,
Russ

No way Russ. How many amps have you had laying around at the same time and swapped out? There are very large differences between my Carver PT's, Silver Nine T's, Soundcraftsmens, Jolida and Manley amps. They all have their own personalities. As a matter of fact sometimes I miss the sound of a particular one and end up swapping it in for awhile.
madmax

RuSsMaN

Solid state Chuck, solid state (and just power-amps, not integrateds). And once again, to a *degree*.

Cheers,
Russ

rlw

Preamps. A preamp is actually a simple version of a power amp, isn't it? It takes a signal, and may "pass" it through without amplification [below unity gain] or amplify it [above unity gain].

A power amp takes a signal, amplifies it, as well as converts it to AC - so it seems like the power amp does even more. In fact, the power amp might have [typically about] 30dB of gain.

So, preamps do less to the signal. They don't make AC, they don't add as much gain.

It seems to me that if power amps sound the same, then it should follow that preamps should all sound the same.

Who thinks that all SS preamps sound the same?

HBombToo

Originally posted by rlw

A power amp takes a signal, amplifies it, as well as converts it to AC - so it seems like the power amp does even more. In fact, the power amp might have [typically about] 30dB of gain.

help me out here... what does convert it to AC mean?

also if I may add another comment Carver made was regarding output impedance. Carver tries to make a SS amp sound like a Tube amp by reducing the impedance. Perhaps if we do hear differences could that be the impedance of the different amp output stages by manufacturer?

Just a quick clarification and observation to a very interesting topic.

HBomb

joe6pak

burdette.

I understand what you are saying about normal listening levels. I just do not agree. As I stated, my comparison was made at low, moderate, and high levels. Even at low levels I can hear detail that simply was not present with the Denon. When I demo equipment, I always try to listen to low level sound first. I want to hear what it sounds like at normal listening levels. I feel that this should be done when testing any equipment at any price range. Sometimes this is confusing to the sales people and sometimes this is not possible because of competitive noise, especially in places like circuit city, best buy. I have not driven anything to distortion levels for years. I have turned this system up pretty loud, but was no where near distortion. With this system there is no way a person could stay in the room at distortion db level without suffering severe ear damage. This Krell stuff has much clean power.

joe

rlw

Originally posted by HBombToo


help me out here... what does convert it to AC mean?

also if I may add another comment Carver made was regarding output impedance. Carver tries to make a SS amp sound like a Tube amp by reducing the impedance. Perhaps if we do hear differences could that be the impedance of the different amp output stages by manufacturer?

Just a quick clarification and observation to a very interesting topic.

HBomb

Well, you can't feed a speaker DC for too long...the signal going to the speaker is AC.

The signal coming from your source/pre-amp is DC.

So, a power amp has an input stage that handles DC.

The outputs are AC.

What happens in between, without getting into any details, is what I am calling "conversion".

burdette

joe6pack and all... concerning actual *listening* experience, I think every single post on these forums has an implicit "in my opinion" even if it isn't written. I think MOST of us agree that speakers sound different and that we all don't agree on what is good or better. ****, everyone can't even agree which Polk is "best." If this weren't so, there wouldn't be hundreds of speaker manufacturers, most with loyal patrons. I find it harder to take that approach concerning some factors of electronics.

So, I don't think many of these discussions have an "end"... we each simply state our opinions and realize we don't agree. For me, I'm comfy in the realization that I'll never have to drop many thousands of dollars on separates to get performance that I believe is not a compromise from the perspective of real-life listening conditions. I'll only have to make sure that the components I buy are electrically compatible with whatever speakers I find myself buying (current supply vs. need, etc).

madmax

Originally posted by RuSsMaN
Solid state Chuck, solid state (and just power-amps, not integrateds). And once again, to a *degree*.

Cheers,
Russ

We can leave the Jolida and Manleys out of it. Well, even the Soundcraftsmens for that matter. Let's just compare the Carver PT-1250's, Silver Nine T's and the Sunfire. (Forgot about the Sunfire earlier) All three Carver amps. Two of them try to sound like tube amps. All three sound amazingly different. "Amazing"... get it? Heh heh. Sorry, a little Bob humour there. The PT's are very clinical, the Silver's are much more mellow and the Sunfire is in your face with glory but not nearly as clean of a backround. Even these three amps from Bob himself sound so different I could pick them out of a blind test (assuming I knew the 3 options). Maybe he is going deaf?
madmax

TroyD

Wow, what a great thread. Man, the things you miss while you are away.....

First of all, I am going to agree to a certain extent with what Brother Bob says. If you take two SS amps of equal power ratings and run them well within thier stated capacities, I think the differences are going to be subtle. I agree that the big differences in amps are how they handle overload as Bob talked about. I also think it takes more than a couple 30 min demos before you can speak intelligently on the characteristics of amps. Again, I agree, that to most folks, the differences are subtle.

As far as the double blind test, I feel that many audiophiles are afraid of it. Bob Carver proved that the folks at Stereophile couldn't reliably distinguish between the m1.0t and the Conrad-Johnson Premier 5 tube monoblocks. I'll be honest enough to admit that in a TRUE double blind test while I could probably tell that the amp was different I doubt that I or many others could say 'Ok, that's a Mac or that's a Krell' or what have you. If you can good for you but I'm going to say that the vast majority of us can't. It's been shown that professional gear reviewers can't.

I agree with a lot of what Bob says, I think it's a good read.

BDT

mantis

Russ,
Yes I have taken blind test many times.......this is what Liv4fam and I do in order to pick what sounds better when we are in HARDCORE DEMO MODE........
One of us sits in a chair facing away from the speakers and have no idea what is what.......(all shootouts are done this way for fairness and whatever we are into at the time)The other will swapout the peice under demo........we both hear things alittle different and most of the time pick different fvorites out of the shootout due to what one wants and likes.........This is very fun to do....I love doing blind test..........just turn your head and look the other way.......just like that.........have someone else do the switching for you,so you have no idea what your listening 2......You'll be suprised what you hear........all you use is your hearing.........not your eyes.......

When you conduct a seeing test....lack of a better term....It's more possible to favor one thing over another due to what your juiced up on that moment.