Hey everyone, new to the forum, hoping somebody can help me out with some ideas.
The aforementioned pre-amplified that I have starts to emit a very high pitched squeeling noise after playing for about 15min. The frequency of the noise is fairly high, some people can hear it others can't. but I am able to record it on my iphone and amplify it for other to hear.
I sent it in to a local Tube gear builder/repair guy, for an unrelated issue,to be gone over and have any necessary repairs performed. He replaced the coupling capacitors in both channels with comparable Mundorfs.
Also replaced the 2 6DJ8/6922 tube with NOS Amperex Holland tubes. touched up some solders here and there cleaned contacts and selector switches.
This high frequency noise is still there. I've tried switching out the tubes with multiple different kinds. No luck.
Sidenotes:
-the frequency isn't constant, I can hear it changing pitch at idle with no signal going in.
-changing the input selector makes no difference
-noise gets louder as the volume knob is turned up.
Thanks,
Lee.
The aforementioned pre-amplified that I have starts to emit a very high pitched squeeling noise after playing for about 15min. The frequency of the noise is fairly high, some people can hear it others can't. but I am able to record it on my iphone and amplify it for other to hear.
I sent it in to a local Tube gear builder/repair guy, for an unrelated issue,to be gone over and have any necessary repairs performed. He replaced the coupling capacitors in both channels with comparable Mundorfs.
Also replaced the 2 6DJ8/6922 tube with NOS Amperex Holland tubes. touched up some solders here and there cleaned contacts and selector switches.
This high frequency noise is still there. I've tried switching out the tubes with multiple different kinds. No luck.
Sidenotes:
-the frequency isn't constant, I can hear it changing pitch at idle with no signal going in.
-changing the input selector makes no difference
-noise gets louder as the volume knob is turned up.
Thanks,
Lee.