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!



:confused:

[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,Cl asse,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?:confused:

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?:confused:

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.

[Zero]

These points bring up something I have always found to be quite interesting. How often times our opinions of gear is ironically influenced by sight and not by sound. We look at the size of the speaker, its driver placement, and of course, the name. - the same applies for other components.

[HBombToo]

Originally posted by rlw

The signal coming from your source/pre-amp is DC.
So, a power amp has an input stage that handles DC.


I feel like a friggen idiot over here! This is stuck in my short term memory and i can't shake it. What am I misunderstanding?

I thought an amp provided gain to the analog signal provided from the preamp out which is also analog.

analog being something like ~ SIN(W)...

DC being W=0 so SIN = 1 i guess?

Been a long time for the HBomb... so what does it mean a preamp is a DC source?

with respect
:confused:

[caseymou]

got me thinkin a little here. I thought the incoming analog signal from either the tuner or other source was neither ac or dc but a distorted signal with peaks which vary with amplitude and frequency depending on the source. I think I have actually examined the fm signal on an o scope in class after building a fm receiver and this is what I saw.

Btw, does anyone have a link so I can read the "blind" test where the professionals were embarassed? I think this would be an interesting read.

[TroyD]

I don't have the link but here is what El Roma had to say about it and I'll bet he can recite it word for word:


The Carver M1.0t, rated at 200wpc @ 8 ohms, 350wpc @ 4 ohms, is an okay amp. Like BDT said, it was "transfer modified" by Bob Carver to sound like a pair of $5K C-J Premier 5 TUBE amps. This was NOT his choice. His challenge was to the hemaphrodites at Stereophile magazine. Specifically, "I can make my new 200wpc, $699 retail power amp sound INDISTINGUISHABLE from any other 200wpc you choose." The clever fellows at Stereophile decided to throw him a curveball. They chose tube monoblocs.

He performed this magic in a friggin' motel room in Santa Fe. He had 48 hours to accomplish it. After 24 hours, and serious listening, they agreed he was not quite there yet. HIS amp had better low end than the C-J's. So he sent them back home, muddied up the low end on his M1.0t, and when they came back 24 hours later, they had to agree, his amp was virtually IDENTICAL to the C-J's. But when they printed the results in the next issue of Stereophile, the scumbags HAD to dilute the mans success by saying "Well he may be able to do it in a motel room, but we doubt he can assure every one coming off the assembly line will be the same."

The article was in a 1985 issue of stereophile but it's one of the back issues that they won't sell you. Gee, I wonder why.

BDT

[burdette]

Stereo Review used to consistently test speaker wire using double-blind testing. They didn't attempt (nor therefore succeed) in embarrassing anyone, but they consistently found that people can't hear the difference between zip cord and esoteric wire.

The signal coming from a source component is voltage-varying AC. However, an amplifier can pass electrons in only one direction, i.e. DC, so the AC audio signal is placed on a DC offset. The amplifer output is current-varying DC. As this current varies through the voice coil, the magnetic flux varies and the magnet therefore moves the coil.. moving the cone.. moving the air.. producing sound.

Tubes tend to be slower reacting than transistors.. i.e. tubes have a lower damping factor, making them less able to handle transients, usually described by listeners as a mellow sound. What some tube-enthusiests describe as harsh sound from transistors is simply the transister amplifier reacting fast enough that it doesn't miss any of the signal, as the tubes do. On old source material without many fast transients, transistors can show the limitations of the source material. So, indeed, tubes might sound "better" due to their limitations.

As we've discussed previously, the different "sound" of different amplifiers, especially tube amplifiers, does not come from them being "better", it in fact comes from some limitation they possess that causes them to introduce distortion to the output signal. Given that this sort of distortion is pleasing to many people, they claim tubes are "better" amplifiers. The Carver example shows this... he actually had to *diminish* the performance of his amp in order to match the sound of the tube monoblocks. He had to introduce distortion that otherwise was not present in his design.

This is also why two decent transistor amplifiers operating within limits are indistinguishable. It is only when one produces distortion that they can be discerned. More expensive transistor amplifiers are less likely to distort, meaning they can produce a clean signal at higher volumes when a lesser amplifier would begin to clip, for example.

... if you care...

[rlw]

Originally posted by burdette


The signal coming from a source component is voltage-varying AC. However, an amplifier can pass electrons in only one direction, i.e. DC, so the AC audio signal is placed on a DC offset. The amplifer output is current-varying DC. As this current varies through the voice coil, the magnetic flux varies and the magnet therefore moves the coil.. moving the cone.. moving the air.. producing sound.


Are you *sure* about that?

I'm fairly certain that an amp's output is AC - not DC. In fact, I'm pretty sure that, at DC, the x-over's inductors are a dead short, and the x-over capacitors are an open circuit. Isn't that how caps and coils behave?

In fact, some tube amps include output transformers to prevent DC from going to the speakers. Sand amps typically include capacitors somewhere in the signal path to prevent DC from hitting the speakers - most power amps are NOT DC coupled.

You are, however correct in your correction of my brain-fart that line level is DC. Line level is AC too.

So...I think my original question needs rephrased: A power amp takes an AC signal, applies 30dB of gain, and outputs an AC signal. A preamp takes an AC signal, and typically applies no gain .

If all SS power amps sound the same, shouldn't all SS preamps sound the same? I mean, you can't really overdrive your preamp.

Do we think that all SS preamps sound the same?

[HBombToo]

Interesting is your position...

Liike I've said, I are an engineer.

Hmmmmmmm...........
is that too many?

[faster100]

For goodness sakes just listen and love what you can afford, everyone on here has his price point and it doesnt matter what 500.00 or 5000.00 dollar item sounds like until you can afford it and take it home. thats what is so fun about this hobby... no one person has listened to everything out there and even if they did, whats it matter unless they can actually purchase it and tell us all how it sounds, you like it keep it, you don't return it then.. testing is fun but at the end of the day i will never own a 20,000 system and someone else on here might. so why should i concern myself with that the 20 grand system sounds like compared to my couple grand system, its all apples to oranges, Its like if you can afford the best polk speakers all the sudden they are the best, then joe smoe can only afford the cheapest and he thinks they are the best ever....... I know we all like a good conversation but lets leave it up to the people like BOB carver who have made a life long job of audio gear to decide what they think about the amps they build, after all they should know right??

[rlw]

Originally posted by HBombToo
Interesting is your position...

Liike I've said, I are an engineer.

Hmmmmmmm...........
is that too many?

I'm just asking, honest. I'm only interested in learning/understand as much as I can about this stuff. Feel free to tell me my questions make no sense, just explain why to me, and let me ask more.

I figure the more I understand, the better. A friend of mine says that "It's a great day when we can learn something new", and I tend to agree.

[RuSsMaN]

Originally posted by rlw

Do we think that all SS preamps sound the same?

Well, just for ****s and giggles, after another run through tonight, with limited gear to 'test', I still feel the preamp colors / changes the sound much more than the amp (hopefully will at least blind, if not double blind different amps tomorrow).

Sticking with my ADC16/2 cd, Signal Cable Interconns, MIT Term 5 speaker cable, and SDA CRS+ AND Kef Cresta 2's, I ran through some swaps with the m400a. I chose to stay away from the internal phono stages, and keep it as basic as I could - Line input stage, line output stage.

The pre's interchanged were a Luxman R-113, Yamaha C40, and NAD 1130. This was not a blind test, just me, and the gear. 2 runs were done, one at 85 db avg, one at 90 db avg. Music was South Hampton Dock, and The Final Cut from Pink Floyd.

Lux- Smooth low end, strong (but not forward) mids, laid back, but pleasing highs.

Yam- Smooth low end, but almost punchy, listenable midrange, highs a bit bright.

Nad- Smooth, but not as much authority as the Lux on the lows, strong (once again not forward) mids, detailed, but not overly bright highs.

The Nad and Lux were very very close, all adjectives above are used very lightly.

Even though the Kef's and SDA's are obviously different speakers, the pre's all seemed to stay consistent on either speaker, as far as the effect on the overall sound.

I'm keeping the cave setup with this gear for the weekend, and calling in some Yamaha, Nad, Nakamichi, and Marantz amps to test the original question.

How about passive preamps, or 'direct' switches (not only by-passing user adjustable tone controls, but actually re-routing the signal inside the pre). All tone controls add some sort of distortion, and the signal MUST pass through these (unless said 'bypass / direct switch is available). Is this why sand preamps sound different from each other?

What differs between a preamp's input stage, and an amp's input stage? Obviously the output stages are different, with the amp having to push much higher current on the speaker cables, than the pre on interconns.

Thanks for all your input guys, great read, keep it coming.

Cheers,
Russ (yes, I did this sober)

[caseymou]

Russ,
I think your "drunk" posts are much more entertaining.

[rlw]

Originally posted by RuSsMaN



How about passive preamps, or 'direct' switches (not only by-passing user adjustable tone controls, but actually re-routing the signal inside the pre). All tone controls add some sort of distortion, and the signal MUST pass through these (unless said 'bypass / direct switch is available). Is this why sand preamps sound different from each other?

What differs between a preamp's input stage, and an amp's input stage? Obviously the output stages are different, with the amp having to push much higher current on the speaker cables, than the pre on interconns.

Thanks for all your input guys, great read, keep it coming.

Cheers,
Russ (yes, I did this sober)


Interesting.

What about sand preamps that have no tone controls?

I think there's a lot of factors at play. In another thread, I posted an article by Nelson Pass about speaker cable. In there, Pass talks about his real-world experience of the nasty effects of oxidation on the amp/speaker connection.

Could it be that things like connector quality, parts quality, build quality, and parts layout all contribute to the sound of a preamp? What about things like background noise - in our world, there seems to be more and more RF, and crappier AC mains. Wouldn't a preamp that takes these things into consideration, making sure to shield the signal path from RF and internally generated noise have the potential for sounding better?

At the extreme, what about some of those silly-expensive preamps that actually have a power supply which take the mains AC, convert it to DC, then back to AC to get "clean" power have some sonic advantages with "dirty" AC power? Wouldn't any improvement of the power supply yield good results?

Wouldn't these same considerations apply to power amps? If I introduce RF into my signal path at the input stage of the power amp, that sucks just as bad as having it at the preamp. Likewise, if I have noise on my AC mains, and the amp power supply doesn't do much to filter it, isnt' that bad? What if I have a substandard connector or PCB?

The other thing I'm confused about by Carver's claims. He does claim that unless overloaded, SS power amps sound the same. Yet, in the same interview, in the previous statement, he says that he took one of his SS amps, and changed the way it sounds prior to production so that it sounded like his tube amp.

So do all other SS amps sound like the pre-production version, or the version after making sonic changes to [hopefully] improve it?

[TroyD]

This is just MHO, and in no way am I claiming to be an expert, but, I think that we have to look at the whole statement. I think what he is getting at is let's say you take a flat test tone at a reasonable volume then two SS amps will sound similar. It's when make the amp really work (and I don't think that you neccesarily have to push the amp that hard) that the differences come out in the details. It's how the amp reacts. Again, that's just the way I read it.

BDT

[burdette]

Originally posted by rlw


Are you *sure* about that?



Of course not. It made perfect sense when I wrote it.. I'll rethink it based on your comments and see what my brain tells me. Perhaps I was insane for a moment. Thanks.

[rlw]

Originally posted by burdette


Of course not. It made perfect sense when I wrote it.. I'll rethink it based on your comments and see what my brain tells me. Perhaps I was insane for a moment. Thanks.


LMAO!

[rlw]

Originally posted by TroyD
This is just MHO, and in no way am I claiming to be an expert, but, I think that we have to look at the whole statement. I think what he is getting at is let's say you take a flat test tone at a reasonable volume then two SS amps will sound similar. It's when make the amp really work (and I don't think that you neccesarily have to push the amp that hard) that the differences come out in the details. It's how the amp reacts. Again, that's just the way I read it.

BDT

Troy, this is somewhat of a smart-ass comment, but: I don't listen to test tones, do you?

So, if we're saying that real-world demands end up making amps sound different, well, I agree.

For the record: I'm making no claims on being an expert either. I'm just trying to understand this little hobby thing.

[TroyD]

Sure, don't we all listen to test tones? heh, heh.....

No worries, for the record, I do think amps are inherently different but my point is, and I think Bob's is, like you say, how the amps react that really differentiates.

BDT

[mantis]

I think thats why It's so hard to believe that SS amps sound alike.They certianly sound differnt to me.It's hard to find 2 brands to sound alike.Under real world listening,I would go as far as saying that maybe 50% of people can hear differences.It takes a sharp listener to hear it.Tones are tones,if people knew what they where listening for ,I bet the numbers would increase.Just my opnion.Alot of people don't have such cridical ears.Actually I think thats a good thing.Happiness can be found alot quicker.

This subject was interesting to read.I have found amps of all kinds to have there own personal way of expressing themselves(damn, that sounded sorta twisted).

As far as being an expert on amps.......I'm far from it,I just know what I can hear.........or not hear..
Dan

[jcaut]

Saying that Bob Carver is sharper than me concerning the workings of an amplifier would be something of an understatement. (Ha-ha) But reading it carefully, I'm not surprised about what he said.


provided neither one is overloaded in any fashion, they'll sound identical. That's a big if.


It's very easy to do this (overload, in some form) if you don't have a big juicy amplifier.

Point is (and I think it was already made above, but I'll just re-state) that it's not difficult to run up against the limitations of your amplifier. You might not even be aware that the amp is being overloaded but for the subtle sound differences-- that some people can hear. In other words, it's the way that the amp reacts to real-world (not gross, clipping-type) overload, that accounts for the differences we hear.

Assuming fairly capable amps (and unfortunately I think that excludes *most* receivers), driven completely in their "comfort-zone", being fed equal inputs, I think it would be difficult to hear the difference. I haven't had the opportunity to test this out, so I may be completely wrong. I'm inclined to believe Bob though.

[joe logston]

there is not that much difference in amp unless you run out of power, its mostly up to the speaker load and how lould you pay them its all in the power supply of the amp and how the amp handles the ohms of the drivers, a clean pre amp makes some differants in a clean gain and good valume control. clean power is the word.
im on bob carvers side