Allo Volt +D PSU noise

[johnk]

Hi,
I have been running an Allo Volt +D for a few years and I have recently noticed a lot more background noise. I have tried 4 different PSUs to see if that was the cause and I noticed that the different PSUs caused different levels of noise and at different frequencies (150Hz for my usual one and around 4500Hz for a spare laptop PSU I tried).
My uneducated guess is that some aspect of the PSU filtering is starting to fail. I had a look on the board and noticed that the colour a few of the capacitors near to where the PSU is connected are starting to fade (see photo).
I am wondering replacing these capacitors would be likely to solve my noise issue. Any thoughts? Also any suggestions of suitable replacement capacitors would be welcome.
Thanks,
John

 

[wwenze]

The colors fading are generally not a concern by itself. Why some capacitors fade faster than others however, this is not a topic I feel comfortable discussing (or rather alleging) in this thread.

Isn't the Volt +D two separate amplifiers each with it's own power supply section? Is your noise on one channel only? If it's on both channels I would check cable/AC connections and your source equipment instead.