Ed: every heard of rebranding?
BTW last time I checked THATcorp didn't sell a single opamp...
No never heard of rebranding, what is that? Pretty sure if it drives 600 ohms but not 500, it was a ground up audio design.
THAT makes opamps and labels them for specific purposes.
THAT Corporation 1510-1512 Audio Preamplifier ICs
Unfortunately in the HPA-1 case, the design could not go all out cost no object. Sometimes I wonder what an audio artist like Jam will turn up designing for companies with similar to Silbatone's way of doing audio.
IMD may be caused by nonlinearity in the output stage, including nonlinearity due to power supply issues.
Filters have various effects, they attenuate aliasing but don't fully eliminate it. They have a sound too, which is why some dacs offer multiple filter choices. Much more could be said on that, maybe later.
Most dacs are plagued with multiple issues that muddle together, affecting the sound. The effects of that can leave listeners with the false impression they are hearing all there is to hear.
What are the problems? Power supplies, decoupling, layout, clocks, output stages, passive component nonlinearity, etc. Doing all those things well is expensive and complicated.
Given that consumer devices like dacs typically retail for about 5 times the cost of the parts, a $400 dac may have a parts budget of $80 including the case and retail packaging, not to mention the requisite multi-layer PCB (which is not cheap).
The designer has to make compromises, lots of them. Say you want a super regulator for the clock, a few AD797 opamps to make an output stage. The parts budget will be blown before the dac is done. You can't do those kind of things, and the other things that would help sound quality, and do it all for $80. The designer's challenge is to balance out the design choices to make the best overall compromise, do the least harm. It means a $400 dac would need most of the parts replaced to produce the best sound the dac chip is capable of (IME certainly true for dac chips like ES9038Q2M).
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As most of the time the impedance of the feedback resistance is between 2 and 10k in audio, this is not rocket science either: If the circuit is correctly designed (power pins well decoupled) there is only to ensure that each opa is optimally compensated. One or two little caps to change, add or remove.
False positive vs false negatives, still haven't settled on which one?
Let him/us know how to set up the listening test so that he/we can try it.
Compared to solo voices, choral or group vocals tend to combine into one composite sound texture, details of individual voices are less distinct or missing. Probably easiest to hear on recordings that haven't been Autotuned (pitch synced) and or Vocaligned (time synced). The old Steely Dan 'Black Cow' CD rip works for hearing that effect. There are lots of other ones that will work too. The idea is to listen for differences of the effect between dacs, between amps, etc.
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How do you set up such listening test? Give us the details so that we can try it.
Thanks Mark, I'm thinking the voice being an acoustic system should be very linear and could therefore be a good subject for this kind of test?
No, in many cases. Simply an easy spec to add 600 Ohm load drive to catch outlying applications. The real key is to forgo input current compensation on bipolar op-amps.
Low noise and distortion are universally useful.
I'm retired now and have no comment on the situation at anyplace, though I'll bet a couple JRC op-amps get virtually all the consumer level sockets where price is almost all that matters.
Those are not op-amps and I repeat you are wrong on the 600 Ohms, we never did a single audio "ground up" op-amp design (whatever that means). You would be hard pressed to find an op-amp that works to full spec at 600 Ohms but craps out at 500.
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It seems likely that perceptually speaking we are naturally inclined to be pretty good at noticing subtleties of human voices. They can communicate hints as to intentions that can be very useful to notice, say, for example.
You conveniently ignore some of the "sound of" issues PMA has found to be nonsense. Should we go back and list them?
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True. As time goes by and if he keeps learning how to hear more and more things well enough to pass his ABX criteria, then maybe it will get more and more interesting to see what happens here. He is about the only one who cares to try going down that path (maybe ScottJ/Matt too). Don't know how far either will go at this point, maybe it will get interesting enough to shake up some old beliefs.
On the other hand, its about like Audio1/Demian said. Some things may be audible, but multiple small and or not well defined causal factors are likely going on at once making it hard work to separate them out. IMHO that is the main reason we don't see more clear evidence published about some of what is/can-be audible. It is hard work to sort out, and if someone does learn something useful, that understanding may be of more value as trade secret material verses for the value of publishing in the hopes of career enhancement.
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Such a marketing talk.
Because not enough money (number still unknown to you) was spent on studies of what people hear and therefore we cannot rule out the audibility claims of DACs, amps, etc. 2.0. 🙄
My issue here is that the stylus is only used contacting vinyl, there are no SS LP's. The folks at B&K are great at analysis, I wish they had attempted to explain the lowering of the resonant frequency but at the same Q.
In Pavel's test it was the difference in the sibilance I noticed most. I'm just interested in more descriptive terms and possible correlations than better, that's all 🙂
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