Power cable dilemma


I have to ask the community for an explanation to account for an issue I encountered this past week. 
 

I received a Mark Levinson ML-23.5 amp this past week. I plugged it in with a high end power cord I purchased years ago (because it looked better than the cheap cord that came with the unit. Lol). I switched from an ML-9 so I had certain expectation of the sound. After listening for about 30 minutes, I noticed that the amp did not sound very dynamic. I got up to go feel how hot it was and the heat sinks were barely warm. I turned up the volume and listened for another 15-20 minutes. I got up to check the temperature and the heat sinks were still barely warm. Also, I was playing the amp at volume level 28 on my Cambridge 851N. That is pretty high. The sound was still lifeless. I shut everything down and just sat there, dejected. Was the amp defective? Was it just a bad match? Were my expectations too high? I don’t know what made me try it, but I swapped out the power cord with a plain black cord and powered up the system. Unreal. I was now listening at volume level 22 to the same song, with staggering dynamic impact, at what seemed to be a similar volume. Furthermore, after about 20 minutes, I went up to feel the amp and the heat sinks were very toasty! So the question is: what could have possibly been wrong with the original cord that would result in lower volumes and no heat buildup? It is like it was throttling the current. To me, a cord either connects or it doesn’t. It works or it doesn’t. There should not be an in between. Does anyone have an explanation for this?

jrimer

@jrimer 

I asked for a source other than the manufacturer or a reviewer.

If we're looking for lab tests, after searching, I can't really find any. I thought for sure there would be at least one or two out there, but as of yet, I haven't found one. It looks the only tests out there (beside manufacturer's descriptions) are mainly from audiophiles who have bought these cables, and have provided there own personal listening evaluations.

If we’re looking for lab tests, after searching, I can’t really find any. I thought for sure there would be at least one or two out there, but as of yet, I haven’t found one. It looks the only tests out there (beside manufacturer’s descriptions) are mainly from audiophiles who have bought these cables, and have provided there own personal listening evaluations.

It’s true that the vast majority of evidence supporting the claim that power cords can indeed impact sound quality is anecdotal. However, I would argue that the combined weight of such evidence is far too great to dismiss with the wave of a hand. I simply don’t find it credible that such a meaningful percentage of audiophiles are all slaves to propaganda and various, related biases.

Furthermore, there are individual examples that carry much greater weight than the average testimonial. Take, for example, Paul McGowan of PS Audio. He is a well-known figure, who has produced many, many videos in which he attempts to answer questions from audiophiles, and his company is well respected, from what I can gather.

So this relatively public figure, who certainly knows a fair bit about audio engineering, was for years selling power cords produced by his own company, but found that the high-end offerings of another brand (Audioquest) were superior, and not only decided to use them in his company’s extremely expensive reference system, but also to sell them through their website.

In the video (linked below), Paul says:

"we put every ounce of engineering knowledge that we had into [the PS Audio AC12] cables"

"Holy crap! It was so obvious...the Dragon cable blew away our AC12 – just blew it away. I wish that wasn’t true"

He also claims to have done A/B blind testing, and that "everyone" hears the differences. He challenges anyone who is skeptical of different power cables making a difference to come and listen.

The video is only ~six minutes:

Paul McGowan on cables

 

To be clear, I have never used Audioquest cables, but even though Paul himself is unable to explain why there are such differences, it strains credulity to believe that he, and the others who were exposed to such tests on the reference system, somehow suffered from mass delusions.

This also touches on what I have argued for years, based on my personal experiences, and those of more than a few other audiophiles. If confirmation/expectation biases are the explanation for why people hear differences in cables, then how is it possible that some have, at least at times, had precisely the opposite experience? In other words, like Paul in the above example, I have had several experiences over decades of developing systems in which I was disappointed in a newly acquired component, despite having had great incentive to prefer it.

That doesn’t mean that I have "golden ears", nor that I never suffer from such biases. But it certainly does illustrate that hearing differences in cables can be the result of relatively objective listening.

As a final note, Paul does stress that his impressions of the cables were confined to their synergy with very specific PS Audio components, and within that system. And I agree that context and synergy are crucial.

I think this conversation is about a claim that there have been quantum leaps in power cord technology in the last 5 years, not if there is a difference in power cords in general. 

Just get a UPS ADC from Amazon or Staples. You’ll see a huge difference. Then… you’re running DC from a battery. Clarity like never before. Any IC.  

@jrimer 

Getting back to your initial post, did you ever try this?

It would be interesting to see what the results would be if you switched the sequence of cables around next time in another study of your perception of amp temperature and performance, ie, starting out next time (with a cold amp) with the "plain black cord" for the exact same duration of time you used the Pangea cable last time (as the first power cable used). If the same results take place, maybe it’s just the amp venting some of it’s heat to the heat sinks after being powered up for a certain total length of time (using a combination of both AC cables), no matter what AC power cables were used, and in what sequence.