Why is my amp vibrating?

[wwenze]

I'm trying out one of those Chinese amp one can get off ebay and taobao. It's an LA4625-based chip amp.

It is vibrating a little when turned on. If I up the volume and the bass it will vibrate more and to the beat.

Could it be the transformer? But there is no coil whine, transformer buzz.

Other than the transformer, is there anything else that can move inside an amp? Dun tell me transistors can vibrate if you push it too hard.

 

[analog_sa]

Dun tell me transistors can vibrate if you push it too hard.

That's exactly what is going on. Some heatsinks make this a lot worse and sing. And people are surprised that solid state gear requires good support for optimal sound.

 

[Stuey]

If it is the heatsink, you can place small rubber pads in between the fins to minimise it.

 

[tinitus]

Use a wooden stick placed against your ear, and touching various parts you may be able to locate the problem
A bit scary to hear how much mechanical noise there is in a simple amp
Mostly a lot comes from transformer
Even if its apparently not audible, it will be with the stick

 

[star882]

Check the inductors and the capacitors.