PC Challenge Test Results

As a result of the "PC challenge" thread, I've now had a chance to put a high-end aftermarket PC to the test in my system. First, sincere thanks go to Albert Porter for helping to set up the test, and especially to Jim of Purist Audio for his hospitality in loaning me a PC. Jim also was quite gracious about how long the testing took.

Jim sent me one of his Dominus power cords. This PC clearly uses very, very high quality components and the level of construction appears outstanding; this is certainly a PC at the highest level. I'd guess that you could jump-start a car with this wire! I don't know if this cord costs $50 or $5000 (bet it's closer to the latter), nor did I want to, to avoid possibly influencing the test.

My initial listening took two approaches. After having powering-up the cable for 72 hours as was recommended, I listening in a very relaxed manner, without trying to identify any specific differences. Did my system seem more or less enjoyable than I remember? The answer is yes, it did seem more enjoyable; there seemed to be less "stuff" getting in the way of the music perhaps, a clear although not huge difference, and there also seemed more of a foundation to the music. The question then became whether or not I could pick out specific differences? Again, compared to my recollection of the system sound the answer is yes. While the changes were relatively subtle there appeared to be more and better bass (slightly deeper and more defined, more of a visceral impact) and the vocals somewhat more natural - less "in your face", perhaps. The lack of bass depth is an inherent shortcoming of my system, but the vocals had never stood out as a problem area before. Overall, the sound seemed more transparent, quite a feat given I think that's one of the primary strengths of my system. Bottom line for this part of the evaluation: the Purist PC definitely added to the system, although subtly.

Now, that being said there I had some very strong concerns on the above given that this was a sighted evaluation. It could very well have been that I expected and was listening for exactly those effects (not the vocals, though - that surprised me), or that my audio memory of the previous setup was flawed. I wanted to try some blind evaluations as a test. I have no ABX-type of setup, so was unable to conduct any tests that I'd consider truly scientific, but tried something that was informative nonetheless. With the help of my brother, we did some rapid-switch testing: he flipped a coin and either switched between the Purist PC and stock, or not. I typically listened for 2-3 minutes to the Purist before the switch/not-switch and an equivalent time after before deciding, and got 7 right out of 12 trials; we then tried it with the stock cable first and I got 5 out of 8. I've not yet hauled out my old statistics textbooks, but am pretty sure that this would fail most reasonable hypothesis (say, "there are sufficient differences (95% confidence level) between these PCs that I can identify them correctly 80% of the time).

So what does this mean? Nothing beyond that it appears, in my system, that I probably cannot discern any purely audible differences between my stock cord and the Purist. Any broader conclusion is unsupportable from my testing alone, although I do suspect that equivalent results would hold for the population at large. But - and this is a big but (no jokes, please!) - before the blind testing I did perceive an improvement in my system; for many, this is sufficient and they may gain a real benefit from aftermarket PCs. In my case, though, I'm better off adding a sub than investing in aftermarket PCs.

Nice system JHunter and also thanks for taking the Pepsi challenge. I also like HWY's test suggestion. The cords and inputs could later be switched on the players and the tests ran through again to see if the same results come up. I am certain that you must be tired of it all by now though, as there's nothing like getting back to listening to the music, instead of the gear.
Thanks, Jhunter, for taking the time to share your experiences with us. You were honest in describing what you heard, and that is a great service to this community. I share Albert's thoughts about the possible unintended consequences of the attempt to do some blind testing by swapping the cables in and out. I also experience the phenomenon that moving my cables requires a re-settling period before the sound gets back to where it was.
JHunter, I think the above posts express it well. Thanks for taking the time to run the test and providing your unbiased results.
Thank-you Jhunter for the time and willingness to test the cable. As expected we solved nothing, only raised more questions. I agree with Albert that the second part of the test has potential for error, but I'm happy you made the effort.

I think the true test will be in time. Will you decide your missing "something" when you send back the cords, or will you remain content with the system as it was.

I wish we could have resolved this issue, in that it becomes very old and tiring, but so far we have not. Thanks again for the open mind. (that's really all I'm looking for) J.D.
Like all the others have stated, thanks for posting your HONEST results. All of our "debates" here have NOT been in vain if we help open minds and explore new avenues that some folks otherwise might have left alone. Once again, thanks for sharing your experience with us. Sean