MakeMineVinyl
Major Contributor
As the witness is dragged out of the courthouse screaming, kicking and yelling about supposed conspiracy theories about listening to something....It seems like you're leading the witness..
As the witness is dragged out of the courthouse screaming, kicking and yelling about supposed conspiracy theories about listening to something....It seems like you're leading the witness..
They get to "measure" it thoroughly, but not a "listen".No, but I don't believe they just throw up their first design either.
I have to be cheeky with respect and apologies - any UK made gear in that?
Actually, in a previous job in which I was designing a miniature camera for instrumentation, we hired an optical engineer who designed the "correction" lens for the Hubble telescope. He told some pretty horrendous stories of how the original engineers did all sorts of measurements and still screwed the pooch with an essentially useless lens system.They get to "measure" it thoroughly, but not a "listen".
Of course mediocre engineers can't pull it off.Actually, in a previous job in which I was designing a miniature camera for instrumentation, we hired an optical engineer who designed the "correction" lens for the Hubble telescope. He told some pretty horrendous stories of how the original engineers did all sorts of measurements and still screwed the pooch with an essentially useless lens system.
I have no idea how he did the Hubble correction. We hired him to design a lens for us, not so we could interview him.Of course mediocre engineers can't pull it off.
How did they come up with the correction system? Did they get to prototype it and test it? No. Again from theories, data from the messed up images, and prior measurements.
I think you will find Serge had a pretty long career in audio electronics but failed somewhat as a hifi dealer since he told people the truth, which they had not heard before, and things like "you don't need to upgrade your amplifier it is already audibly transparent" to a potential customer, instead of assuring them the latest item would "blow what they had out of the water" and recommending expensive cables to go with their new purchase.Your future as an amplifier designer is guaranteed (to be short lived). But at least you can say you had it your way...while it lasted. Just don't expect me to fly on an airplane you designed.
Although I never designed equipment for consumer HiFi, I designed several pieces of pro equipment for tape duplication, recording and broadcasting studios and some Test & Measurement equipment. In no case did we ever do any subjective listening tests, nor did our customers on acceptance. They simply ran a set of standard measurements and then passed the equipment as fit for use.Your future as an amplifier designer is guaranteed (to be short lived). But at least you can say you had it your way...while it lasted. Just don't expect me to fly on an airplane you designed.
I only have first-hand experience with Halo. I would suggest that there's no sound shaping of any sort.
Depends on what you interpret sound shaping as. Halo amps/pre-amps are based on the Curl design philosophy part of which holds higher harmonics are bad and engineered for it. Typically you will find that these designs have relatively higher second and third harmonics which are more tolerated in that philosophy (how audible they are is a different question) and the higher order harmonics pattern sharply attenuated.
I've designed some pro gear too, and in those cases never did any listening tests beyond making sure it didn't have buzz/hum or noise when connected to other gear in a real world studio situation. Different industry.Although I never designed equipment for consumer HiFi, I designed several pieces of pro equipment for tape duplication, recording and broadcasting studios and some Test & Measurement equipment. In no case did we ever do any subjective listening tests, nor did our customers on acceptance. They simply ran a set of standard measurements and then passed the equipment as fit for use.
I was fortunate in my career that my customers were experienced engineers who knew exactly what they were buying and why. When I tried to be a HiFi dealer I was spectacularly unsuccessful as I applied the same criteria to selling amplifiers as I had previously to broadcast infrastructure, and couldn't understand why my customers were different.
S.
But should it be? What's the difference between a piece of pro-audio equipment and a piece of consumer audio equipment? Why should the criteria for design and manufacturing be different?I've designed some pro gear too, and in those cases never did any listening tests beyond making sure it didn't have buzz/hum or noise when connected to other gear in a real world studio situation. Different industry.
Curl's huckstering claims aside, the distortion spectra look pretty typical, i.e., good. I've yet to measure an amp that didn't have 2nd and 3rd as the predominant harmonics. Mine on the JC5 will be published shortly, but here's Stereophile's measurements of another model. I don't see anything here that would be atypical for old-school AB amps or anything likely to be audible.
It isn't a binary of "good" vs "bad".
Thank you. A very learned and well reasoned treatist.I think you are confused. The ABX test is the easy environment in which to distinguish one amp from another. If this test is failed it defies common sense that there will be actual perceptible differences that will be discovered in everyday use. The latter presents profound obstacles to making any kind of comparison between audio gear that has similar performance specs.
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There are well established reasons for why you perceive that amps sound different. In almost all real world playback environments two amps will never sound exactly the same.
What people don't acknowledge is that the perceptual biases that cause us to hear audio differences when none truly exist is that they actually do make things sound different. The perception of difference is not an 'illusion' or an 'imagined perception' it is a real, actual perceptual difference.
Even playing back the exact same passage on the exact same system will lead to different perceptions of sound. Our minds are constantly adjusting our perception and focus.
Couple this with the many objective reasons why comparing two amps in the real-world will lead to the conclusion that they sound different:
- Unless the amps have some kind of super calibrated gain structure, playbacks levels between amps will be actually different
- the problem of level matching is compounded by the different gain structures and resolution of the volume knobs.
- one amp might not be operating to spec
- tube amps or vintage amps can have a non-flat frequency response
- if tone controls are available on either amp, this can seriously compound efforts to understand how the amp sounds.
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This discussion is the 'vampire debate' of audio and it's about as settled as anything can be that competently designed amps are sonically in-distinguishable under specified conditions. This has been proved over and over with ABX testing.
To decide whether the results of such ABX testing are meaningful to us, potential user of an amplifier, requires interpretation and an analysis of how the conditions for these ABX tests relate to 'real-world' listening concerns.
Richard Clark ran a relatively famous $10k challenge for anyone who can distinguish two amps in a blind ABX test. Nobody ever claimed the prize after 100s of iterations. (If you've never read about this, it is truly a fascinating experiment worth learning about https://www.stevemeadedesigns.com/board/topic/193850-richard-clark-10000-amplifier-challenge/)
He had some strict conditions (strict in the sense that they must be met, not that they imposed unrealistic expectations on the amps or listeners)
- amps must be commercially available from reputable companies
- amps must be working (functioning at spec)
- test is performed on dynamic speakers (as opposed to something like an electrostatic design)
- amps level must be kept under either clipping or 2% THD 20Hz to 10kHz
- must be level matched to .05 db (on both speakers)
- absolute polarity and L/R are consistent between amps
- if the amps have a different frequency response then one must have some EQ applied to make them the same
- amplifiers must be brand name, standard production, linear voltage amplifiers
- program material must be commercially released music
Within these constraints are a wide range of possibilities and parameters under which the test could be conducted!
Contenders could:
- pick any two amps to compare (including car amps, tube amps)
- use any speakers
- use any music
- control the level of the playback
- can take as long as they want and switch between amp A and B as many times as they want
- if EQ is applied to equalize frequency response they can pick which amp gets the EQ
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The question for a potential user of an amp is: do the conditions and results of a test like the Richard Clark $10k Amp Challenge provide meaningful guidance on the selection of an amp suitable for purpose?
I argue that this provides a ton of useful, practical information for a consumer. It eliminates the worry about aspects of amp performance that are very difficult to impossible to evaluate in normal listening environment.
Good point of outside the box things I didn't think of. Checking for things that can happen when the amp isn't inside it's normal operating envelop. Don't seem that bursts of noise or volume changes sound like anything that would require "critical" listening though.. And having some measurement gear hooked up to it would reveal the issues under these circumstances as well as a speaker.Does the amplifier clip off sound when it enters sleep? Does it clip off sound when it wakes up? Does the amplifier make strange noises or pops when it wakes up/goes to sleep? These things can only be determined by critical listening. If I just measured things, and shoved it out the door, I'd be toast.
Measurements of Pass amps have shown that he tweaks them to sound a particular way and doesn't shoot for total transparency.I made three definitive statements about the ICEpower versus the 12X more expensive Pass Labs X150.5 amp:
I’m afraid you’ve been misinformed or you misunderstood. There is no requirement for ABX tests that a highly constrained environment be used. There are some requirements, but you can listen the way you normally do in your home.I don't find much to debate except that audiophiles do not evaluated amplifiers (or other components) in the highly constrained environment of that Blind ABX test.
You'd be surprised at how critically you have to listen for little noises and responses from the amplifier during situations like this. It literally takes hours with all sorts of program material to finally be able to sign off the design. There's no test equipment on Earth that can evaluate the subjective sound of leaves blowing in a soundtrack and how it relates to an amplifier not clipping those sounds as it goes to sleep. Things like the integration time of the circuit which listens to the audio and a lot of other details. And of course failing to catch these things would be extremely critical if a customer calls to complain about it!Good point of outside the box things I didn't think of. Checking for things that can happen when the amp isn't inside it's normal operating envelop. Don't seem that bursts of noise or volume changes sound like anything that would require "critical" listening though.. And having some measurement gear hooked up to it would reveal the issues under these circumstances as well as a speaker.
Pro audio gear is more utilitarian. That's not to say there's some progear like microphone preamps don't have a lot of voodoo mystique in their marketing. They do.But should it be? What's the difference between a piece of pro-audio equipment and a piece of consumer audio equipment? Why should the criteria for design and manufacturing be different?
I accept that some people may prefer a solid aluminium box, hewed from the solid as opposed to a black 19" rack mount case, but apart from the cosmetic, what distinguishes pro from consumer? (other than Bullshit)
S