The Digital/Analog Dialectic

[garylkoh]

If you switch sources in the middle of a track, will the participants know?

Yes. My preamp does a 1/4 sec mute in between input sources and you can hear the relays click. If it doesn't mute, you might hear a click in the speakers as well.

[garylkoh]

Gary, are you planning on comparing the vinyl to needledrop digital at different sampling rates?

Tim

I hadn't planned on, but if we have time it could be very interesting. I was going to do just 96kHz, but we could just as easily pick one piece and do 3 sampling rates. However, that would be digital to digital comparison and not analog to digital.... If no one can hear the difference between the sampling rates, then it means 24bit 44.1kHz is "enough".

[Ron Party]

Yes. My preamp does a 1/4 sec mute in between input sources and you can hear the relays click. If it doesn't mute, you might hear a click in the speakers as well.

Is it possible to remove the sources to a different room such that the participants won't hear the relay clicks?

[c1ferrari]

I do agree with you that an even more interesting demo would be a controlled playback of recordings where both an analog master and a digital master were recorded at the same time.

Hi Gary,

Perhaps, Bruce B. can assist or knows of someone who knows of someone who can assist, etc., etc - think Yule

[garylkoh]

Is it possible to remove the sources to a different room such that the participants won't hear the relay clicks?

Good point - the less the participants see of the system, the better. I have long balanced interconnects - may be I can move it behind a screen, but another room might not be possible. That could also be beneficial as the record player then won't be subject to the vibrations of the loudspeaker.

[andy_c]

Burmester Top Line Ph100 phono stage with built-in 24bit/192hz ADC

Does the A/D converter of this piece of equipment have an analog input? Having such an input could be important for setting up the test, due to the need for level matching of analog and digital signal paths. From my POV, there's several conditions that need to be satisfied here:

1) The gain from A/D->D/A should be as close to 1 (0 dB) as possible (preferably within 0.1 dB or so).
2) The A/D converter should not clip ever.
3) The A/D->D/A conversion process should be operated at signal levels within its optimum dynamic range.

As to whether digital is ready for prime time, that's kind of like asking if vulcanized rubber is ready for prime time. Even asking such an absurd question smacks of political posturing to the max.

[rbbert]

Just a little pet peeve of mine, but to be more accurate you are comparing analog LP's with digital; you should consider adding analog tape as an additional source or even reference (as hinted at above in the suggestion to use LP and digital versions of the same source, presumably analog tape). I somehow persist in the illusion that LP's have as many as or more imperfections than digital when compared to an excellent analog tape.

[Bruce B]

Just a little pet peeve of mine, but to be more accurate you are comparing analog LP's with digital; you should consider adding analog tape as an additional source or even reference (as hinted at above in the suggestion to use LP and digital versions of the same source, presumably analog tape). I somehow persist in the illusion that LP's have as many as or more imperfections than digital when compared to an excellent analog tape.

If you want to do that, just record the LP's

[garylkoh]

Does the A/D converter of this piece of equipment have an analog input? Having such an input could be important for setting up the test, due to the need for level matching of analog and digital signal paths.

Yes - the analog input will be an LP. Using a 1kHz test tone from the Analogue Productions Ultimate Test LP, I level match the analog and digital signal paths using a true RMS voltmeter at the speaker-level inputs. The analog output of the DAC is higher, so digital volume control is employed to reduce the gain.

To further level the playing field, the analog volume of the phono stage is also reduced by one click. Both the DAC and the phono stage can be used as a preamp directly into a power amp because they both have variable gain - on the DAC it is a decent implementation of digital volume (24bit with dither), on the phono stage it is an analog volume control.

From my POV, there's several conditions that need to be satisfied here:

I am doing my best to assemble a system that will be equally optimized for analog and digital. I thank you for your suggestions.

1) The gain from A/D->D/A should be as close to 1 (0 dB) as possible (preferably within 0.1 dB or so).

Within the limits of the difference between the output gain of the phono stage and the DAC, yes.

2) The A/D converter should not clip ever.

Yes. The phono stage has adequate headroom in its input circuit for the lowish output of the cartridge I am using. Ahead of the RIAA and before the output stage and before the ADC, the phono stage allows gain setting. The phono stage has a clip LED before the ADC, and the gain is reduced until the clip LED never flashes, and then another 3dB lower.

3) The A/D->D/A conversion process should be operated at signal levels within its optimum dynamic range.

Within the constraints of level matching and leveling the playing field, yes.

As to whether digital is ready for prime time, that's kind of like asking if vulcanized rubber is ready for prime time. Even asking such an absurd question smacks of political posturing to the max.

By saying that this is political posturing you assume that I am trying to find a winner and favoring one other the other. You many have entered this thread through "What's New?" and missed the raison d'etre for this forum. It bears repeating here:

A dialectic is a dialogue between two parties (who may have conflicting viewpoints) and yet wish to seek the truth of the matter through discussion and refinement of those ideas and view points. It is unlike a debate - in which both sides wish to win the debate either by persuading the other side that they are right, or proving the other side to be wrong. It is also not a rhetoric, which is designed to persuade an audience to side with their viewpoint. An important characteristic of a dialectic is the ability to put up with contradictions - that there can be opposite viewpoints which are equally valid - whereas much of Anglo-American intellectual culture trends towards positivism. Hence, it is sometimes referred to as a "Continental" philosophy, but the culture of dialectical thought first flourished during the period of the "Hundred Schools of Thought" in China from 770BC to 220BC (which ended with the burning of books and burying of scholars by the Qin). Let's hope this dialectic does not end that way - but the thoughts and ideas discussed and refined in those days still profoundly influence lifestyles and society up till today.This being the Whats Best Forum, I hope that some of the ideas developed will advance the development of our music reproduction/audiophile hobby.

The beauty of a dialectic is that we are not looking for a winner, or to prove a point, or to convince anyone to our point of view. It may not even have a conclusion - it is a dialog and a discussion, and the participation in the dialog and discussion is an end in itself. As with scientific experiments, not every experiment ends with a successful conclusion. But the lessons learned in that failure is useful. A dialectic may not end in a conclusion - but the journey through the discussion is enlightening.

We may not find or determine anything, and we may never meet in the middle, but civil discourse will go a long way towards understanding one another.

[garylkoh]

Just a little pet peeve of mine, but to be more accurate you are comparing analog LP's with digital; you should consider adding analog tape as an additional source or even reference (as hinted at above in the suggestion to use LP and digital versions of the same source, presumably analog tape). I somehow persist in the illusion that LP's have as many as or more imperfections than digital when compared to an excellent analog tape.

Having heard analog tapes in MikeL's room, I would love to do that. However, I have zero experience with tapes (unless you call standing on a bar stool helping my Dad thread the tape on his Akai as experience). May be that can be the subject of another listening session, but I'll probably have to get help from BruceB, MikeL or Ki Choi. I wouldn't know the first thing about optimizing tape playback.