https://www.youtube.com/watch?v=W-qqdYBsgZY
With Bob Carver. Enjoy.
Horrible sound quality, horrible golden ear propaganda.
But he's the 'anti-audiophile' guru all the objectivists love. What happened?
But he's the 'anti-audiophile' guru all the objectivists love. What happened?
Who? Carver?
He went rogue, long ago.
The host is out to lunch, as well.
I'll give Carver this - his description of the audible aspects of the technical causes of the sonic imperfections common to tube amps is OK as far as it goes. However, as far as I got into this tedious and poorly-made video, he did not point out that for amps reproducing music, the nonlinear distortion can't be euphonic except to those who like listening to sonic garbage.
His 'Silver Seven 700' would look good in your living room Arnold. And you could heat the house this winter too.
@Roy h.b. Timbre:
https://hydrogenaud.io/index.php/topic,3974.html#post_tos12
didn't get far with this video as i'm absolutely not interested in tube amps. but im curious, is the distortion that they introduce predictable and model-able? if yes, then one could practically outCarver the Carver by coming up with a DSP that distorts the signal in a similar fashion to his ridiculously priced amps, like the aformentioned one for example. kinda like he did himself a while ago: https://en.wikipedia.org/wiki/Bob_Carver . now that would be a fun ABX test to do!
Could never understand what Peter Aczel saw in him or Mondial Designs for that matter.
didn't get far with this video as i'm absolutely not interested in tube amps. but im curious, is the distortion that they introduce predictable and model-able?
Absolutely.
if yes, then one could practically outCarver the Carver by coming up with a DSP that distorts the signal in a similar fashion to his ridiculously priced amps, like the aformentioned one for example. kinda like he did himself a while ago: https://en.wikipedia.org/wiki/Bob_Carver . now that would be a fun ABX test to do!
There are a number of ways to do ABX tests related to adding various amounts of nonlinear distortion to clean audio files.
Math model tools like Matlab ($$$) and Octave (free/shareware) can be used to add nonlinear distortion of your choice to audio files you want to test with.
Audio editing programs like CoolEdit Pro and Audition have built in functions for doing some ar things.
Their is a VST plug in (potentially usable with the Audacity freeware editor called Distorder that has potentially useful capabilities along these lines: http://www.ohl.to/about-audio/audio-softwares/distorder
The AddDistoration program that you can download from here http://www.audiosignal.co.uk/freeware.html is a stand alone program with similar gaosl. You can read more about it here: https://www.stereophile.com/content/euphonic-distortion-naughty-nice-page-2 .
i see that adding the distortion isn't difficult at all, but how would one go about replicating the same "model" of distortion from one of his tube amps for example, how do you reverse engineer it? i guess harmonic distortion can be quite predictable, but from what i understand IMD may only enter audibility with some particular signals, and thus very individual to every amp.
i see that adding the distortion isn't difficult at all, but how would one go about replicating the same "model" of distortion from one of his tube amps for example, how do you reverse engineer it? i guess harmonic distortion can be quite predictable, but from what i understand IMD may only enter audibility with some particular signals, and thus very individual to every amp.
You should perhaps stay aware that the loudspeakers drivers have their own audible THD and IMD, the medley of the non-linearities of the amplifier and the loudspeakers is impossible to predict without the complete system IMHO.
I really don't see the point, TBH.
I really don't see the point, TBH.
It seems to me pretty dificult to comment the amplifier flaws when the loudspeakers are unable to reaveal them.
i see that adding the distortion isn't difficult at all, but how would one go about replicating the same "model" of distortion from one of his tube amps for example, how do you reverse engineer it? i guess harmonic distortion can be quite predictable, but from what i understand IMD may only enter audibility with some particular signals, and thus very individual to every amp.
You can fairly easily measure the output of a power amp while it is amplifying a certain test signal, and find out the size of each harmonic that it generates with that signal. You can then use software to add the same harmonics in the same quantities to music, and obtain a pretty good approximation of what that amplifier would do in real life under the similar circumstances.
I really don't see the point, TBH.
It seems to me pretty dificult to comment the amplifier flaws when the loudspeakers are unable to reaveal them.
Doesn't the same problem apply to actual usage of the amp and speakers?
I really don't see the point, TBH.
it's more of a theoretical exercise i guess. if the whole point of tube amps is their particular distortion profile, then wouldn't it be much cheaper and easier to simply emulate those distortions with some DSP and a proper solid state amp? it's pretty much what Carver did himself as that wiki i linked to shows...
I really don't see the point, TBH.
it's more of a theoretical exercise i guess. if the whole point of tube amps is their particular distortion profile, then wouldn't it be much cheaper and easier to simply emulate those distortions with some DSP and a proper solid state amp? it's pretty much what Carver did himself as that wiki i linked to shows...
It might be easier to emulate those and cheaper to run them, but the problem is: they wouldn't sell. It'd be like emulating the sound of a different engine in your car through the speaker system. I know some cars actually do that, but with tube amps, that's kinda their main selling point. Having an "emulated amp" is just not gonna sell.
It's like selling homeopathy: homeopathic "medicine" isn't sold because it works, but because people want it.
Here's the deal:
The idiots who would want such a thing are the same people who reject anything digital in the signal chain.
If the idea is to see whether you can fool someone in a blind test, the same thing applies: idiot believers won't take the test and will contort logic beyond all recognition fabricating all sorts of reasons why any properly administered test of a competent algorithm doesn't show any true positives.
it's more of a theoretical exercise i guess. if the whole point of tube amps is their particular distortion profile, then wouldn't it be much cheaper and easier to simply emulate those distortions with some DSP and a proper solid state amp? it's pretty much what Carver did himself as that wiki i linked to shows...
It might be easier to emulate those and cheaper to run them, but the problem is: they wouldn't sell. [...] Having an "emulated amp" is just not gonna sell.
In the ProMusician world a lot of profiling (guitar)amps exist, e.g. https://www.kemper-amps.com/ (https://www.kemper-amps.com/). And they sell good.
I really don't see the point, TBH.
It seems to me pretty dificult to comment the amplifier flaws when the loudspeakers are unable to reaveal them.
Doesn't the same problem apply to actual usage of the amp and speakers?
Whatever stuff you use, in our highly reflective domestic environment, randomly placed uncalibrated loudspeakers sounds bad.
I will not comment the "strange men choices" because they have pushed the oddity button too far for me, i look at it like a kind of resarch through the human beliefs... a little bit like alchemy.
BC have opened a door in my brain (he clearly know how to do it with its customers... as all very good merchants) with its 1ohm "purely resistive" loudspeaker coil.
How can you qualify as a "purely resistive very low back EMF" loudspeakers driver coupling when its coil is linked to a large highly inductive amplifier output transformer... relativity, the back EMF is generated by the moving coil, not the static one and the static coil is dominated by its resistance.
He is doing his job, he blur your mind and put his seeds inside.
it's more of a theoretical exercise i guess. if the whole point of tube amps is their particular distortion profile, then wouldn't it be much cheaper and easier to simply emulate those distortions with some DSP and a proper solid state amp? it's pretty much what Carver did himself as that wiki i linked to shows...
It might be easier to emulate those and cheaper to run them, but the problem is: they wouldn't sell. [...] Having an "emulated amp" is just not gonna sell.
In the ProMusician world a lot of profiling (guitar)amps exist, e.g. https://www.kemper-amps.com/ (https://www.kemper-amps.com/). And they sell good.
Sure, in that sort of niche market, they might sustain a bit, but it'll never be the main target consumer base. Some producers might want to emulate tube amp sounds for period correct film sounds tracks, etc. but they'd used software for it.
What we're talking about here is "creating the tube sound, without actual tubes" for the general consumer. Most consumers wanting tube sound, don't want just tube sound, they want tubes, and the sound kinda comes with it. Selling tube amps is about selling nostalgia and elitism, not about perfection. You could sell function correct emulated tubes, but you wouldn't sell the nostalgia and elitism, etc.
The tube aficionado sort of audiophile market is already kinda small, people being OK with "faked tubes" would be an order of magnitude or several of those smaller.
And just to be clear, it is not the tubes per se that result in the distortion, but the transformer that matches the high impedance of the tubes to the low impedance of the speakers.
And just to be clear, it is not the tubes per se that result in the distortion, but the transformer that matches the high impedance of the tubes to the low impedance of the speakers.
Kinda-sorta.
I've studied this issue extensively over the years, and I agree with several of the points that Carver raised in the video. If you cut though the pseudo science, the most audible aspect of vintage amps is their generally higher source impedance.
Carver alluded to, and measurements and tests confirm that while tubed amps tend to be much more nonlinear at full output, at typical listening levels, the tube distortion is relatively low.
In some relatively well-engineered tube amps like McIntoshes, the nonlinear distortion is below audibility at any reasonable in-spec operating level. Even in the boutique freak-show SETs, at the power levels that most people listen to these things to at, the nonlinear distortion is still probably inaudible.
PDQ comments about output transformers is true, but their limitations come in two ways. Transformers can be free of audible distortion if they are well-designed and used at relatively low levels. But if they are undersized or otherwise poorly-designed, they can have audible distortion, particularly at low frequencies. They limit ultimate performance via another route - their phase shift at high and low frequencies. This makes applying enough inverse feedback tricky or impossible.
However, tubed amps and even some legacy SS amps might have source impedance issues. Even nominally good SS amps often have stability-enhancing RL networks at their outputs and outside the feedback loop that cause potentially audibly rising source impedance at high frequencies near the top of the normal audible band. Any legacy SS amp that has a single power supply for its output stage generally has a large DC blocking capacitor that will interact with some woofers to create relatively large amounts of bass boost (YES, BOOST!) - often several DB in the lowest normal octave.
Often, the high source impedance of a tube amp is well-simulated by means of a simple wirewound series resistor on the order of several ohms and several watts. Or. use suitably long very thin speaker cables.
"Any legacy SS amp that has a single power supply for its output stage generally has a large DC blocking capacitor that will interact with some woofers to create relatively large amounts of bass boost (YES, BOOST!) - often several DB in the lowest normal octave."
What is a "legacy SS amp"? How far back are you going in time? 10 years? 20 years? More?
What is a "legacy SS amp"? How far back are you going in time? 10 years? 20 years? More?
Modern class D amplifiers are also "damped" by their output filters, some of them can be peaky in the highs if the there is an impedance mismatch.
http://sound.whsites.net/articles/amp-classes.htm
"Any legacy SS amp that has a single power supply for its output stage generally has a large DC blocking capacitor that will interact with some woofers to create relatively large amounts of bass boost (YES, BOOST!) - often several DB in the lowest normal octave."
What is a "legacy SS amp"? How far back are you going in time? 10 years? 20 years? More?
I'm talking second generation SS amps - late 60s, early 70s.
Notable because they use silicon output devices (not germanium types like the first generation), typically no coupling transformers, single-ended power supplies, output coupling caps. Lots of Japanese receivers and amps, as well as the Dyna 80 and 120, the Heath AR 15, AR amplifier, etc. The AR amp was a bit of a throwback as it had a driver transformer. Mostly topped out at 50-60 wpc. The next generation included the early Phase Linears, Crown DC 75 and 300, Dyna 400, etc - notable because they had split power supplies, no output coupling caps, more power 150-200 wpc, but still had SOA problems.
Thank you Arnold. Very interesting.
Are there any modern power amps that you are fond of?
Bob Carver's Phase Linear amps and TFM series amps are still very highly regarded and sought after on ebay. Good value (power) per dollar. I always respected his 'outside the box' approach in his engineering.
Thank you Arnold. Very interesting.
Are there any modern power amps that you are fond of?
Lots of them. You later on mention value. Generally the two best ways to get watts for good prices, and the two best ways to do that are would be AVRs and amplifiers for professionsl audio. AVRs give you a lot of watts per dollar, but their maximum power output for channel might be on the low side. Amps for pro audio like Crowns, QSCs, and the like come in various power ranges that vary from a lot to totally humungeous. Used within their ratings, they can both sound great.
Bob Carver's Phase Linear amps and TFM series amps are still very highly regarded and sought after on ebay. Good value (power) per dollar. I always respected his 'outside the box' approach in his engineering.
Carver does a lot of things these days that make me suspect of his sales efforts. For example, for years he went around suing speaker companies based on a patent that he had for a subwoofer. The patent was eventually found to be invalid for a number of reasons including the fact that there was prior art, some of which Carver had previously used in his own commercial products. That automatically invalidates the patent, but Carver picked mostly on small companies that would settle rather than go through an expensive court fight. Eventually, he picked on somebody with deep pockets who cleaned his clock in court. It was fraudulent bullying all along.
Thank you.
I like what I see in the Crown's and QSC's. I especially like the smaller size and the price. Good power per dollar.
Thank you.
I like what I see in the Crown's and QSC's. I especially like the smaller size and the price. Good power per dollar.
The biggest problem with applying pro audio amps to home audio is their cooling fans.
Yes, I noticed the fans. I suppose that you could replace the OEM fan with a quieter one after doing some research.
On a side note, I would to participate in a (volume matched) blind listening test between an regular Pro class D amp and a so-called NCore or ICEpower class D amp just to see if sonic differences exist. My guess is probably not.
Yes, I noticed the fans. I suppose that you could replace the OEM fan with a quieter one after doing some research.
On a side note, I would to participate in a (volume matched) blind listening test between an regular Pro class D amp and a so-called NCore or ICEpower class D amp just to see if sonic differences exist. My guess is probably not.
These days power amp fans are often set up to track the needs of the amp, so if you don't turn things up, they may even be stopped.