this is intended only for 230V/50Hz owners of P15/P20 units.
When there is silence in your room (it means without music), please focus your hearing on P15/P20 chassis in your system, and answer (2 choices available):
My P15/P20 is on the rack
My P15/P20 is out the rack in an open space
I can hear a subtle hum from the chassis at my listening position
I can hear a subtle hum within 3 ft
I can hear a subtle hum within 1 ft or closer
I cannot hear any noise even with my ears close to the chassis
0voters
My aim is to understand if P15/P20 owners - only about the 230V/50Hz model - are experiencing a hum/buzz, more a low pitch, coming from the unit, a mechanical noise probably due to toroidal vibration.
A few threads on this forum seem to give evidence that this noise is particular annoying or simply present mainly with 230V power.
I love the P15/P20 so much and I firmly recommend to feed amps and sources to the regenerator because of wonderful improvements in SQ but Iām curious to investigate if this noise issue is quite common among users.
Depending on results we can discuss deeper about solutions or suggestions, hoping this can help also PS Staff to have a better idea on a larger scale about this problem (if really exists).
Thatās exactly what I was thinking about one of mine and why I put this option. In effect itās as noisy as the other one I have out my rack but I couldnāt hear the hum because of its acoustically dampened location.
The percentage of āin the rackā answers might coincide with āno noise or lesser noise audibleā options checked.
Where are you living, EU?
Thanks, yes I sent a video to PS Staff and they are monitoring the unit during last days. They suggested to plug the P15 to the P20 and the noise is still the same, even with THD IN at 0.3%.
Time will tell.
Sorry ignore my vote I didnāt read voltage close. I would recommend yo try tightening the center screw of toroidal transformer if no joy loosen enough to put two half moons of 1//8 Sorbothane sheet between the bottom of transformer and floor and retorque. Or might stack Sorbothane under unit where center screw passes through enough to give the case floor an upward load to dampen vibrations and not sing in the middle
Thanks Max, clever idea. Iām not qualified to open and work internally the P15 but Iāll try to put some dampening stuff on the external bottom to find out if it can attenuate the vibration (and the noise consequently).
If I understand well under the chassis there is a screw, thatās the right point where the toroidal transformer is internally screwed and where I have to put my dampening stuff, is it right?
Anyhow I have to thank @jamesh and Steve from PS Audio in particular, he is taking care of my issue since a few days. Finger crossed.
The cover is easy to pop off. To tighten you might just try the bottom Phillips. But if the nutplate doesnāt have a star washer under it it might turn. I ād give it a go.
Another very odd thing: I took some measurements with the Line EMI meter between wall socket (dedicated line) and P15 sockets. From wall is 50/70 range, from regen 180-220, Iām pretty confused. Same bad values from the P20 sockets.
It seems that the P15/P20 generate a bad EMI signal while it comes clean from the wall. How can it be possible?
I tried plugging the amps directly to the wall and immediately came back, the SQ is far better having the M1200s plugged in to the P15. I can live without measurements, just curious.
I like the SQ better with M1200 plugged in P15 too, but I have other sources plugging in it too. I wonder if a P20 will work better? It is on my upgrade list after streamer. So, may be next year (but I am not sure if there is a SQ advantage from P15 to P20).
I tried the metal doorstep, but I could not find a location that I like it better. I seem to remember it made the SQ warm and a bit murky.
Since it is under warranty, should you just send it back to have it check out? The buzzing sound would drive me crazy too.
I was using the doorsteps on each M1200s, frankly without significant impact on sound, hoping just a less vibration. Since Iām in trouble with the P15 noise, I give them a try. Putting them in different positions, or putting only one on the lid, gave me no results at all, I was giving out when suddenly in that exact position (both together), dang! something happened.
Answering your question: honestly I cannot help you! As you know my previous system (all fed by the P20) cannot be compared to my actual, with separation between amplification (P15) and pre/sources (P20) and most of all after the Room refurbishment, totally a different scenario. Sorry.
For sure when I replaced 2 P12s with a P20, oh wellā¦ thatās was transformative!
Within the end of December I guess youāll purchase the beast!
yup, I may go with the upgrade when I am getting bored with my system. It seems as the SQ of the system going up, I am doing quicker upgrades. How does that make any sense? But I know (not sure about that either) a streamer may be more beneficial. So, it is probably the next move.
There is a metal EMI plate attaches to Wood sounds Gloss Black painted top cover with qty 4 press fit inserts it relies on pressure and friction to stay snug. If you have to remove the 4 corner cover allen stews the wood easily pulls loose from the metal EMI plate. To fix the metal singing to wood. I would take off lid separate metal from wood shot some sealant between them then snap back together. On my p-20 I can pry wood off internal plate with 4 allen head fasteners installed and fasten it back down to press inserts with a good fist smack. So your P-15 likely same.So I would alternately use a long thin metal scraper to pop off wood cover. Do it at back of unit. Apply sealant glue between metal an wood so it doesnāt have excessive squeeze out. Then reseat it to press fit inserts by hand. That should cure the bad vibes. Be sure to use masking tape for cover orientation registration to the inserts.
Thank you, Reading from you it seems an easy process, Iām not that kind of guy, though. Changing a bulb lamp is a challenge for me. I have to fight against my lazy nature sooner or laterā¦
Is there a video or a step by step illustration with pics available on the web, showing how to open and remove the lid prom P15/P20? If I understand well, I can keep it in its actual position, it means that is possible to open the lid from the upper side simply unscrewing the screws on the lateral panels, isnāt it? Not something complex as the DS DAC which needs acting also on the bottom and flipping it.
My suspect is that the noise is coming from some internal stuff, being generated from something more on the right side, where noise is louder even if the door steps weight on the top can mitigate the annoying buzz ringing.
I think I put pictures in the Power component P20/p15 tweaking thread for someone that wanted to do the absorber under lid tweak. I found suction cup to be not necessary i just grab lid from back and pull up these days since back isnāt recessed like front and sides.
I found your pics in that thread, helpful as usual, thanks. Iāll try to uncover the P15 lid first because the P20 is on the rack and itās a harder job.
Once uncovered and powered on I hope a visual inspection could help me to locate where exactly the noise is coming from, without touching anything. Or is not recommended powering the P15 without the lid mounted on top? Iām scared about a wrong step, typical newbie error.
Anyhow Iām having daily mail exchange with Steve Majors who is kindly helping me to find out possible solutions, great customer support from PS and thanks also to @jamesh who in copy.
But I know (not sure about that either) a streamer may be more beneficial. So, it is probably the next move.