73 SF Champ and 66 Vibro champ raspy, ugly high end.

[six el six]

I had a tweed champ once and it sounded wonderful. The only thing it had changed in it were the filters. My current champs sound terrible. Both have an unpleasant high end no matter what speaker I try. Coupling, bypass, and filters are fine as are the ceramics. I test caps under voltage, esr, and with a digital meter. I've heard output transformers failing that could still put out sound but sounded bad i.e. using GEOFEX method primary readings were off. Is there a good way to check a single ended OT? Could it be coming from a bad resistor? All of them read pretty close to the schemo i.e. some drift but nothing crazy.  Thanks.


Bypass caps are new. Coupling caps have been swapped out resulting in slightly different tone but same raspy, annoying high end still there.

Voltages are fine, though a little high. With the wall ac adjusted down with a variac they're normal. Tubes are fine. They've been swapped out with others (many).

[LooseChange]

You have two amps... Both sound bad?
Did they ever sound good? If yes, what changed that both amps would sound bad?
I usually just clip in a good OT into an amp to see if things improve.

[HotBluePlates]

Both of those Champs have a tone circuit which gives a different sound (scooped-mid) than the tweed Champ.

If you don't like the sound of them, is it possible that you simply prefer the sound of the tweed circuit? If so, you might try a tone-stack lift.

But then again, I *really* love blackface VibroChamps. I'd try to talk you into selling the amps and getting the tweed you really want.

[catnine]

I had a tweed champ once and it sounded wonderful. The only thing it had changed in it were the filters. My current champs sound terrible. Both have an unpleasant high end no matter what speaker I try. Coupling, bypass, and filters are fine as are the ceramics. I test caps under voltage, esr, and with a digital meter. I've heard output transformers failing that could still put out sound but sounded bad i.e. using GEOFEX method primary readings were off. Is there a good way to check a single ended OT? Could it be coming from a bad resistor? All of them read pretty close to the schemo i.e. some drift but nothing crazy.  Thanks.


Bypass caps are new. Coupling caps have been swapped out resulting in slightly different tone but same raspy, annoying high end still there.

Voltages are fine, though a little high. With the wall ac adjusted down with a variac they're normal. Tubes are fine. They've been swapped out with others (many).

 Tell me about it . I have posts all over this forum with the high end . I know I didn't like the tone stack lift . I dial the treb down on the amp a bit and bring the vol up on the amp and down on the guitar. that helps . Yet mine is a home brew . I agree with HBP . The SF and BF champs are great but different .