 Show Posts
|
|
Pages: [1]
|
|
1
|
British Style / JTM 45, 50 / Re: Strange noises from my JTM45
|
on: June 30, 2008, 04:15:42 AM
|
|
I replaced the noisy Presence pot, did some additional shielding, moved some internal wiring and the problem is all but gone. The squeal is only there at way higher levels of presence than I ever use. Thanks for everyones help.
|
|
|
|
|
2
|
British Style / JTM 45, 50 / Re: Strange noises from my JTM45
|
on: June 17, 2008, 12:27:22 AM
|
|
I got it made and mounted in a cab by Ceriatone. The only option they fitted was an external bias pot. It is very touchy too.
(The power valves are biased to 38mA and 40mA.)
I can take some photos, what are we looking for?
|
|
|
|
|
3
|
British Style / JTM 45, 50 / Strange noises from my JTM45
|
on: June 16, 2008, 05:39:43 AM
|
|
My new JTM 45 is, what I consider, fairly noisy. That is, a lot of hiss over 1/3 to 1/2 volume.
I have experimented with several preamp valves with little sucess. (My other amps are not noisy with the same guitars, plugged into the same outlets etc.). I can make the amp generate a high pitched whistle if I turn the Presence knob up full. Not just hiss and not feed back type squeal, I mean a whistle. The Presence pot is a little scratchy too. Any thoughts?
|
|
|
|
|
|
to keep the forums alive.