Hi-rez digital, is the analog amp the bottleneck?

Interesting interview with John Siau of Benchmark Media. About 1/2 way down, is this quote:
The 32-bit systems will offer no advantage until converters reach a SNR of about 138 dB, but many other things would have to change as well. The best line-level analog circuits barely exceed 130 dB, many power amplifiers barely exceed 16-bit (96 dB) performance, and today’s best 24-bit recordings barely exceed the SNR of a 16-bit system. Most audiophile systems are limited by the SNR of the volume control circuits.
JA (Stereophile) has made similar comments in his measurements section of recent amp reviews. So what amps are people using with their hi-rez digital audio sourced systems?
There is a lot more to Hi-rez than SNR!
McIntosh MC501s. Read the Stereophile review and see what the comments were regarding it's signal to noise and the high Rez formats. Most rooms in the typical home have background noise that make it impossible to realize high signal to noise ratios.
Hi Bob,

I agree with the preceding responses, and I think that the increased sample rates of hi rez are much more significant than the increased number of bits per sample.

It is probably tempting to think of a 96kHz sample rate as little more than a doubling of the 44.1kHz redbook standard, while an 8-bit increase in the resolution of each sample represents a 256-fold improvement.

But I think that the sample rate increase is best viewed in relation to the Nyquist frequency (the 40kHz minimum sampling frequency which is theoretically required to digitally represent a 20kHz bandwidth). Redbook's 44.1kHz exceeds the Nyquist rate by only about 10% (which is such a small margin that it has always seemed wondrous to me that it works as well as it does). But 96kHz exceeds the Nyquist rate by 140%, and 192kHz exceeds it by 380%. Assuming good implementation, those higher margins should make possible vastly reduced side effects from anti-aliasing and reconstruction filters, those effects having been generally recognized to have limited cd sound quality right from the start.

So my answer to your original question is no, I don't think the analog amp is a bottleneck.

Best regards,
-- Al
Hi-rez is all about the higher sampling rate, not about the improved sample resolution. IOW, 16 bits @ 96kHz is a whole lot better than 32 bits @ 44.1kHz. I'm afraid Mr Siau hasn't got a clue. And besides, who really gives a damn about SNR when so many modern recordings are all compressed any way.
Gotta love Al.

Another great answer my man. I have learned alot from you!

Al is the man!. always read his post and walk away knowing more.

i've been heavily into hi-res dvd's for almost a year now.when done right, the sound is phenomenal imho. night and day compared to most standard redbook recordings. when not done right....there's no point to it.

psa pwt/pwd too pass x1 too levinson 432 works fine for me. i think it's more about the recording itself then the gear (70/30 would be my personal estimate)

4est put it well....."there's more to hi-res the snr"

"I'm afraid Mr Siau hasn't got a clue"

I see no inconsistency between what he said and what you said.

@Bob_reynolds: Check out the Stereophile review of the NAD M2 Direct Digital amp.
I don't think analog amps are a problem in playing back hi-rez digital. However, in my experience digitizing vinyl I would rather have more bits than higher Hz. In other words greater bit depth is more important than higher sampling rates. To qualify my statement, I'm limited to only 96k A/D conversion and my conclusions my not apply to any other equipment other than what I have.
Thanks to everyone. I agree completely about the relative importance of sampling rate versus sample size, but the reality is that we have digital sources with 24 bit samples.

The fact that many recordings are compressed and do not utilize the dynamic range of the media is irrelevant to the discussion.

If the goal is to playback a source signal as well as possible, then the SNR of the analog chain seems obviously important. If our analog electronics can't pass a hi-rez signal cleanly, shouldn't we consider alternatives?

I understand that truncated hi-rez is better sounding than standard CD, but why accept this?

The MC501 is one of the few amplifiers that can match the theoretical dynamic range of such hi-rez digital media as SACD and DVD-Audio.
Yes, that's the sort of comments from JA that I recall reading.
There's a thread up now about the ESS Sabre32 Ultra DAC. People are going to make buying decisions based on sample size with little to no consideration to what happens to that signal once it becomes analog.
Ben & Lev, I appreciate the nice words!

Putting aside sample rate considerations, my feeling is that IN ITSELF the difference between 24 bit resolution and 32 bit resolution will be utterly inaudible. The music doesn't require it, even if the music is minimally compressed and has extremely wide dynamic range, such as some well-recorded classical symphonic performances; the ambient noise levels in our listening environments won't support it; and our ears could at best only marginally hear it anyway, even under the most ideal of circumstances.

However, any practical a/d or d/a converter chip, and its surrounding circuitry, will have a host of error mechanisms that will degrade performance from the theoretical ideal that corresponds to the number of bits being converted. Things like differential non-linearity, harmonic distortion, internally generated timing jitter, passband ripple, inter-channel crosstalk, internally generated noise, etc. Presumably and hopefully the main advantage of having 32 bits of resolution instead of 24 bits, as I see it, will be that those other sources of error will be correspondingly improved.

And concerning amplifiers, my feeling is that I definitely would not place ultra-good signal-to-noise performance among my leading criteria in amplifier selection. The difference in noise performance between a hypothetical amplifier that could approach supporting 32 bit performance and one that supports 16 to 24 bit noise performance is simply not going to be audible, and would most likely be far outweighed by many other sonic differences.

Best regards,
-- Al
Bob - There is a lot of marketing with DACs. ESS Sabre32 with 135dB dynamic range could be as well 24bit (144dB) but "32 bit" is something brand new. On the top of it has THD+N=120dB (20 bit).

In reality converters work up to 20 bits. Sigma Delta goes higher but has timing problems limiting resolution plus similar THD+N limitations.

THD+N is update rate dependent. John Siau's baby Benchmark DAC1 uses 24/192 converter but updates only at 110kHz to keep THD lower.