Sound Quality of Today's PrePros

[Bruce]

Following is a list of some current prepros.

Do you think their S/N ratios, especially in stereo which indicates a great analog stage and power supply implementation, accurately represents their
"sound quality ranking" particularly for 2-channel music?

B&K Ref-30 . . . . . . . . . S/N of 98dB

Rotel RSX-1066 . . . . . . S/N of 95dB*

Lexicon DC-1 . . . . . . . . S/N of 90dB

Lexicon MC-1 . . . . . . . . S/N of 105dB

Lexicon MC-12 . . . . . . . S/N of 111dB

Integra RDC-7 . . . . . . . . S/N of 100dB (stereo)

Bryston SP-1 . . . . . . . . . S/N of 110dB analog, 100dB DSP

Anthem AVM-20 . . . . . . . . S/N of 110dB analog, 102dB digital
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*Legairre's response directly from Rotel




Bruce
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[Steve Goff]

No.




Steve Goff

[Andrew Pratt]

Sony TA-E9000ES with the old firmware is rated at

94 dB analog and 100 dB for digital in.

Most reports indicated that the noise floor was lowered a lot with the more modern firmware so I'm not sure what it would read if benched today.

[Lex]

Well, what is the "sound quality ranking" and by whom? In general, I would say the MC-12 is likely ranked first in this group, regardless of by whom, but rightly so, given the price.

I can personally vouch for the MC-1 sounding better in 2 channel than the DC-1, so the 15 difference there is definitely notable.

Lex

[Bruce]

No absolutes here, I'm not stating there is a ranking list out there by anybody, just a general sense I get from reading lots of reviews and comparisons of these units.

I'm kinda thinking of SNR as a barometer or indicator of the sound quality "potential" of a prepro.

I have no specific biases, as I don't own any of these or other prepros.




Bruce
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[Steve Goff]

I don't think there is any correlation. None of these processors sound as good in two channel mode as some preamps with worse signal to noise ratio.




Steve Goff

[Bruce]

Steve,

Well, I happen to disagree.

I think SNR helps define the design's dynamic range capability while the design of the analog output stages and power supplies defines how well that capability is implemented to provide quality sound.

It is a synergistic equation, so I don't really accept your denuciation, but you are welcome to your opinion.




Bruce
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[Steve Goff]

You asked whether people think that signal to noise ratio accurately represents the sound quality ranking of these particular processors. From my 30 years of experience, in and out of the high-end audio business, signal to noise ratio is simply one of many factors influencing sound quality. Good-sounding circuit topology and parts choice sometimes favor the design with more noise, so long as the noise doesn't dominate the sonics.

The differences between some of these ratings are pretty unlikely to matter much in the real world, even if you believe that manufacturers specs follow a uniform testing procedure and accurately reflect how quiet these processors are. The best DACs today have a resolving capability of about 19 bits. Recordings (halls, microphones, analog to digital converters, mixing consoles, etc.) seldom come close to that in terms of noise, and our playback systems, including the rooms we listen in, won't permit us to hear the full dynamic range of these electronics.

I'm not just talking off the top of my head. I've spent hundreds of hours doing blind and nonblind testing on two-channel preamplifier designs for a friend who is a high-end manufacturer. (He eschews home theater, sticking to phono and linestage preamps.) These listening sessions involved, among other things, comparing different circuits, different power supply topologies, different circuit components, and the like. I've also sold audio gear, designed speakers that we used for several years at CES, and was one of the early circuit modifiers in the late 70s.

Anyway, you too are free to beleive what you like, but I have no basis in my experience for agreeing with your beliefs.




Steve Goff

[Bruce]

Steve,

Thanks, that certainly is a more complete answer. Is there a threshold for SNR that is important to stay above in your experience?

When listing SNR for a product, how would you like to see it specified (specific parameters)?




Bruce
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