I have a Traynor bassmaster, which had been upgraded with some pots and electrolytics. The main filter caps have not been changed. Under very small load, the tubes are sparking on the inside. Blueish color I believe. It worked fine for awhile and granted, I don't use it at all. Pull it out every now and then. Would filter caps be the culprit? The tubes are Mullards and I really don't want to ruin them.