New P5 enters service

I’ve been a PS Audio powerplant user continuously since 2003. I ran a p300 from 2003-05, graduated to a p600 that I used from then until today, and just installed its replacement, a brand-new P5. Here are my first impressions. I had used the SS1 multiwave on the P600, which fed my preamp (EAR 864) and power amp (VAC phi 170 iq). Both use tubes. I was very happy with the sound, but wanted something with more output capacity that didn’t put quite so much heat into my living room. Anyway, tonight I put the P5 in the system, using multiwave 4. While the general character of the music (a jazz LP and a female vocal one) was the same, there was a a noticeable decrease in what I can only call stridence; high frequencies were more naturally rendered, detail previously unheard emerged, Bass was tighter and midrange tone was more realistic. It’s as if the P5 removed something noxious that I wasn’t consciously aware of hearing. Night and day difference? No, but it was very easy to hear, and once heard, very difficult to do without. I don’t plan on trying to do so. The P600 will shift to my vintage system (based on a Fisher 500-C) or find a new home.

A excellent description of the improvements made by a PowerPlant.

Ok, I’m a few days into my new life with the P5 and…I’m confused. Throughout my previous P600 life, I used multiwave exclusively, either the ps2 or ss1 waveforms. Sine didn’t do it for me. So tonight, on a whim after reading posts here extolling sine by other P5 users I switched to sine from multiwave 4. Bass became better focused and for lack of a better word, tighter. Soundstage depth increased, as did atmospherics in live recordings. It sounded like a smoother version of ss1, but with even more dynamics. To say this experience is counterintuitive is an understatement. Am I hearing things or is there a reason my equipment (EAR 864 tube preamp and VAC phi 170iq tube amp) would prefer straight sine?

It is common for tube equipment to prefer sine and not to sound as good with manipulated waveforms. I do not know why.

I recall with earlier PowerPlants it was unwise to change the frequency to above 60Hz as tube heaters were not designed to work at higher frequencies, resulting in distortion - but this is a different issue.

As always, it is best to trust your ears. But it sure would be satisfying to have an explanation.

Manipulating the power waveforms can add power (and/or lower the peaks) which some power supplies are more sensitive to than others. On one end a switching power supply is fairly immune to power waveforms (but obviously has other problems.) On the other some power supplies don’t expect more than a little THD and may not filter out the higher harmonics as effectively or may not be expecting faster ramps than a sine wave, etc. There are also some digital filters that have a special filter to reject 50-60Hz (or more probably 100-120Hz) and this filter will be less effective with manipulated power waveforms.