May be noisy on/off sw.
Put a toggle switch in its place & see if it helps.
Sams does not cover this so if its something in the
amp all you can do is test everything & hope. I do
not believe its normal, a slow clean fade would be.
At Sony we had something called "crystaline growth".
On the ship the salt air would react with anything with contacts.
Switches, pots, etc. Big problem with Jap stuff in the early
days. A plastic bag & silica gel all but ended it.
73 Zeno
