Hi all, I got my hands on a Yamaha P3200 power amplifier at a garage sale that I've been using to drive a pair of Energy Connoisseur C-6 Floorstanding Speakers. I recently started noticing a strange "crickety" noise from the amplifier whenever I play audio anywhere above 20/30% gain. I played a few tones from the audiocheck. net website at 20hz and 200Hz and I think the noise is coming from the coils on the power amplifier board. The issue exists on both channels. I'm not really sure how to go about diagnosing the issue beyond this. I've uploaded the video/photos to imgur. I also have a audio recording of the sound that I'll try to upload on a audio sharing platform and share the link here.
Any help/suggestions would be great. Thank you so much! I've learnt so much from all the discussions here.
Attachments:
Video playing tones at 20Hz and 200Hz on one channel.
Images of the circuitry
Audio playing tones at 20Hz and 200Hz on one channel (TBU)
Any help/suggestions would be great. Thank you so much! I've learnt so much from all the discussions here.
Attachments:
Video playing tones at 20Hz and 200Hz on one channel.
Images of the circuitry
Audio playing tones at 20Hz and 200Hz on one channel (TBU)
If the coils are making a physical noise, this doesn't matter when it is employed in a PA situation, pour a little resin glue on each one to quieten them down.
Hi Jon, I tried this, but it doesn't seem to have worked. Are there any other components on a power amplifier board capable of making a vibrating/shorting kind of noise? I can't seem to isolate where the noise is coming from.
Thank you!
low frequency tones won't make crickety noises.
I suspect the inductors on the active PSU rails, this amp has some sort of class-H using dynamic buck-conversion for controlling the rails, and the ferrite-cored inductors on the PSU boards at left and right are strong candidates as cores undergo magneto-striction (deform mechanically).
I suspect they are nominally run at ultrasonic frequencies, but being modulated by the load they generate intermodulation products that are audible.
I suspect the inductors on the active PSU rails, this amp has some sort of class-H using dynamic buck-conversion for controlling the rails, and the ferrite-cored inductors on the PSU boards at left and right are strong candidates as cores undergo magneto-striction (deform mechanically).
I suspect they are nominally run at ultrasonic frequencies, but being modulated by the load they generate intermodulation products that are audible.
