DC-2 vs. DC-1 v3.1

Posted by Philip Brandes [IP: 171.214.79.26] on August 25, 1999 at 01:10:00
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In Reply to: DC-2 vs. DC-1 v3.1 posted by Jim Staszak on August 24, 1999 at 14:37:33:

Jim:

My apologies for snapping. I took exception to the word "insidious" with regards to subjective evaluation, which struck me as more derogatory than you perhaps intended. I also read your post as an assertion that without the results of blind testing there is no basis to claim sonic differences.

I think the better specifications of the DC-2 with respect to DACs, S/N, and dynamic range are meaningful. You may or may not agree, but your post did not inquire if I had ANY supporting data to suggest improvements in the DC-2 over the DC-1, it seemed to take for granted that ONLY blind test data was valid.

In my opinion, this stance does not widen the marketplace of ideas, as you put it. Rather, it limits the field of discussion to a set of assumptions which, like most a priori arguments about audio matters, resonate with seemingly self-evident truth which becomes problematic when we try to apply it to the real world.

It is certainly the case that perceived differences will quite often disappear in blind test environments. But even these results are far from conclusive because there are serious problems and limitations with even the most conscientiously applied A/B testing. The devil is in the details.

For example, even die-hard ABXers assert the importance of level matching to within .1 dB, because even minute differences in volume have been shown to account for perceived qualitative sonic differences. Yet both the DC-1 and DC-2 volume controls are stepped in .5 dB increments. Unless we are lucky enough to find two sample units that match up within this tolerance, there is no way to level match them to the .1 dB requirement.

Even determining output levels to this level of accuracy involves, at a minimum, verification with a voltmeter at the speaker terminals. How many dealers will go to this effort in a showroom demo? For that matter, how many professionally published reviews supply data like this? Is it realistic to require data that isn't readily available in the real world?

Setting the (in this case insurmountable) issue of level matching aside, we then face the problem of a suitable methodology to conduct a blind comparison. In practical terms, this requires some kind of A/B switchbox since no one can reliably retain an accurate sonic imprint for the length of time it would take to power down amp, swap cables, and power on again (ignoring the potential variance introduced powering the amp on and off).

The problem with an A/B box, no matter how high quality, is the unknown variable it introduces. There is simply no way to determine if the box and additional signal split impose a ceiling on the signal that negates qualitative differences that would be audible without the additional equipment.

In my own system, I have a custom-modified Reference Line Audio passive preamp with their top-of-the line attenuator, silver cabling, and a unity gain pass-through for the Lex front channels. I originally had it built because the DC-1's A/D was not adequate for my turntable; the MC-1's A/D is so much cleaner that I no longer use the passive. I would stack this unit against any A/B box in the world for quality of components, minimal signal path, etc., yet I can still hear a difference when its in my system. I do not believe there is such a thing as a transparent A/B comparison mechanism.

And even if there was, there is still the problem, as others have pointed out elsewhere in this thread, that all else being equal it still comes down to a subjective call by the evaluator. While it is always helpful to get results showing a statistically significant ability to differentiate the products, the absence of same does not prove the null hypothesis that no differences exist. All it proves is that the listener was not able to differentiate the two sources. That is not enough to establish the scientific certainty implied by those who insist on blind testing results as a prerequisite to any claim of sonic differences.

One point I will concede is that I was sloppy in my wording. I would amend my statement to: "From the specifications and subjective reports, I would say the DC-2 will sound better than the DC-1." I would further qualify that (as I have stated many, many times in the past), to say that a V3 upgrade to the DC-1 gets you pretty darn close, and whether or not the difference is worth it depends on your budget and on whether the rest of your system (esp. speakers) is revealing enough. As I said in this thread, a used V3 DC-1 is one of the best deals in audio today.

So I guess a more civil response to your question is there is no blind test data available that I am aware of. Again, I am sorry for the curt response, but I am weary of this argument that "no comparisons are meaningful without blind testing" that gets reflexively trotted out without regard for the difficulties and limitations involved in such testing. Positive blind test results are indeed compelling, but they are not the only basis for selecting components. When such results are unavailable or unobtainable, we do the best we can.

I do not expect anyone to take my word for it, and here and elsewhere I've always encouraged personal evaluation. I too would prefer, but do not require, a level of scientific certainty that may not be realistic in every purchasing decision. My own guidelines are more pragmatic--don't spend more than you can comfortably afford. It's a hobby, not Los Alamos.

Cheers,
Philip Brandes

Follow Ups:

• DC-2 vs. DC-1 v3.1 - Jim Staszak 09:09:01 08/25/99 (0)

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