good point.
I had had similar experience with the old sovtek made 7199. I bought about 6 of them and every single one of them hummed like mad. I ended up deciding to spend a bundle on NOS 7199s and some 6GH8A tubes that will work if you use an adaptor or rewire the socket.
The 7199 is such a great tube though, its a shame that nobody makes it. they were used all over in hi-fi amps, and ampeg used them in a lot of amps
I had had similar experience with the old sovtek made 7199. I bought about 6 of them and every single one of them hummed like mad. I ended up deciding to spend a bundle on NOS 7199s and some 6GH8A tubes that will work if you use an adaptor or rewire the socket.
The 7199 is such a great tube though, its a shame that nobody makes it. they were used all over in hi-fi amps, and ampeg used them in a lot of amps
(11-27-2014, 08:29 AM)bax Wrote: Good that you sorted it out.
Changing the tubes is always the easiest first thing to try. The problem is, sometimes the new tube can have an issue and hum just as bad as the first one. I once bought several tubes, all the same make and model, the first two that I swapped into V1 hummed just as bad. The third one resolved the issue. Two of the new tubes were bad.
I like to keep what I call a gold set of known good tubes that are only used for testing. It's kind of an extravagance but at least I know that I can count on them.