RE: PT that goes "boing" on cold starts

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Posted by Chip647 (A) on November 25, 2014 at 05:17:31

In Reply to: PT that goes "boing" on cold starts posted by FenderLover on November 24, 2014 at 22:05:38:

The boing is obviously a vibration. When it is a problem with a transformer it usually comes about from too great of a load on the transformer. It will boing and heat up rapidly. If you don't have the heat rise, it is just annoying, but it might be possible to fix. Most solid state amps in sheet metal cases boing.

The vibration could be inside the transformer like the bobbin vibrating, the lams vibrating, this could be the source of the sound. The only way to tell if the transformer itself is boinging is to unbolt it and hold onto it when turing the amp on. Likely you will just feel quiet vibration instead of hearing a boing. If it does boing in your hand, send it back.

The metal amp chassis is accentuating and amplifying the noise. There could be a cap (or some other part) in the amp that picks up the mechanical vibration from the transformer and beats against the chassis. Rubber washers may help. Stiffening and damping the chassis will help too.

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Follow Ups Full Thread

Topic - PT that goes "boing" on cold starts - FenderLover 22:05:38 11/24/14 (16)

Thanks! - FenderLover 08:08:41 11/25/14 (11)

RE: Thanks! - drlowmu 15:53:01 11/25/14 (0)

RE: Thanks! - Sherwood Forest 08:38:12 11/25/14 (9)

Fixed! Yay! - FenderLover 18:27:45 11/25/14 (6)

RE: Fixed! Yay! - Jim McShane 19:37:20 11/25/14 (0)

RE: Fixed! Yay! - Sherwood Forest 18:46:17 11/25/14 (4)

Sprague Atom 20mfd/600VDC rated caps - FenderLover 02:56:50 11/26/14 (3)

RE: Sprague Atom 20mfd/600VDC rated caps - Kyle K 12:33:20 11/26/14 (1)

Thanks, for that update! - FenderLover 09:56:05 11/27/14 (0)

RE: Sprague Atom 20mfd/600VDC rated caps - Chip647 05:12:36 11/26/14 (0)

RE: Thanks! - Eli Duttman 08:47:37 11/25/14 (1)

RE: Thanks! - Ray Moth 13:13:29 11/25/14 (0)

RE: PT that goes "boing" on cold starts - Sherwood Forest 07:36:07 11/25/14 (0)

RE: PT that goes "boing" on cold starts - Eli Duttman 07:30:28 11/25/14 (0)

RE: PT that goes "boing" on cold starts - Triode_Kingdom 06:05:33 11/25/14 (0)

RE: PT that goes "boing" on cold starts - Chip647 05:17:31 11/25/14 (0)

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RE: PT that goes "boing" on cold starts - Chip647 05:17:31 11/25/14 (0)

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