TW Express combo?

[rfgordon]

Since this parasitic is in-phase with some part of the amp circuit, I wonder what would happen, just as an experiment, if you swapped the speaker leads? This would reverse the phase of the field created by the speaker motor.

[FUCHSAUDIO]

Have you tried grounding the speaker frame ? Sometimes this helps with oscillations and instable amps. I think it adds shielding to voice coil radiation.

Yes, TR style amps as combos can be fun....lol.

[gcenker]

Since this parasitic is in-phase with some part of the amp circuit, I wonder what would happen, just as an experiment, if you swapped the speaker leads? This would reverse the phase of the field created by the speaker motor.

I actually tried that with no change but thanks for the input.

Have you tried grounding the speaker frame ? Sometimes this helps with oscillations and instable amps. I think it adds shielding to voice coil radiation.

Yes, TR style amps as combos can be fun....lol.

Thanks Andy, I'll give that a try and let you know what happens. Should I ground the speaker frame to the TW chassis? By the way, I got to hear a Frost 100 - KILLER TONE!!

This will be my last post for the next 2 weeks, I'm going to Fiji with the wife - she lets me build my toys with no complaints so I take her on vacations I may not want to come back after 2 weeks on a private island!

Thanks for the input everyone!

[FUCHSAUDIO]

Use the audio ground going to the ground (-) speaker terminal.
Much easier than a separate wire. Enjoy.

Thanks for the kind words on the Frost. It's a beast !

[gcenker]

Thanks Andy, I'll give it a try ... The Frost IS a beast! I think I need 2 of them with 2 4 x 12 stacks to play in a 200 seat club It would be like Moses parting the Red Sea on the first power chord....

By the way, Fiji was OUTSTANDING! We spent 10 days in Vatulele (vatulele.com if interested). No phone, TV, clock, radio or shoes - you won't miss them either!

[gcenker]

Andy, just thought I'd chime back and let you know the offensive squealing was due to both magnetic proximity and some microphonic caps. Replaced the caps, installed the monster 90° combo cable and the problem was gone. I did go the extra mile and installed the ground from the speaker to the chassis as you suggested.

Thanks for the input!

-Greg

[FUCHSAUDIO]

Have a blast..... !