Powerplant12 buzz?

Just received my Axpona No Show P12. I’m noticing a low buzz thru the speakers not tied to volume settings. The buzz is there as soon as I turn my preamp on – before the tubes warm up enough to actuate output relays.

I’ve turned off/disconnected everything, leaving just the preamp and amps, and still buzz. I’ll live with it if I have to since the P12 SQ is significantly better than the P5 it’s replacing, but I’m wondering if anyone else experienced this, and if so, if there’s a solution.

My preamp was dead silent on the P5.

Do not hesitate call PS Audio support immediately.

Expalin to them what is happening they will certainly hep you.
Particularly on brand new unit.

Yes P12 way better than P5 read my thread My Axpons no show P12 arrived.

I just notice that somehow other commentary got included in my reply, ignore scroll back to top of page and read my findings…P12 well worth having over P5

It should not be humming. I also have both P5 and P12. Might want to swap some cables around. I had to remove expensive Cardas ICs from an office system since they were acting like antennas. Cheaper mid-line Morrow Audio ICs immediately corrected the problem.

Yeah, shouldn’t be any different from the P5. Have you tried fiddling with the auto tune and possibly the different MW settings?

Something changed in the preamp upon equipment change/movement. The noise persists even when plugged straight into the wall. So, the P12 is not the culprit here — thank goodness (I really hate sending equipment back)!

Thanks for the responses and thoughts

Glad it’s not the P12 but sorry something weird is happening with the pre now. :disappointed_relieved:

Would a loose rectifier tube possibly cause something like this?

Not sure if this is relevant to your situation, but I found a buzz in my system caused by an HDMI cable. I used to use my Oppo BDP-105 for dual duty (transport feeding DSD and then onto 2ch pre, while utilizing the HDMI to my theater processor), but after removing it from the chain the buzz cleared up, and now I run a CD player and am dead quiet. Thinking that the video feed was causing the buzz. Again not sure how you’re setup, but maybe a help.


For what it’s worth, pulling the lid off is easy. If you want to do that and check the wires for integrity, it may save you a trip to mother.

After much screwing around with all sorts of things, it turns out, the buzz is a result of switching to single ended connection (preamp to power amp) from balanced. The balanced connection is silent; the single ended is not. But single ended sounds sooo much better — confirmed by switching back.

I’m going to live with the buzz.

Try lifting the ground on the preamp.

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Great suggestion! Couldn’t do that on the preamp, but my power amps have a ground-lift switch — that did the trick

Buzz is gone😊