ML331 recapping

The caps reside in each corner of the amplifier. The original caps are large and expensive, but a good option is to replace them with a matrix of smaller caps to the original value.
A matrix of smaller caps provides similar capacity, has a higher thermal and voltage rating and their response time is faster , your amp will sound better as well.
If your handy with a screw driver and a soldering iron you could do it yourself.
I owned a 331 years ago , this mod was done before I bought it.

If you need a knowledgeable shop to do it. Ex Madrigal
Harman employee.

http://www.pyramid-audio.com/

Audiojan-

another +1 vote for pyramid-audio. Let us know when/if you get the repairs completed- I would be interested in reading about your experience. Keep me posted & Happy Listening!

I had mine done at a local authorized dealer, that'll save you the shipping if you have one near by.