Page 59 - Triwatt Custom Lead Amp Builder's Guide

 Is the Chassis vibrating around backboard? Remove the backboard and listen. Use a
Vibration damping strip or rubber gasket between chassis and backboard.
 Is the Chassis vibrating around the tranny? Hold tranny & listen; Are there washers
between tranny & chassis. Flush mounting (i.e. no washers) could cause rattle. Use rubber
gasket between transformer or use washers
 Is the Circuit board mounted tightly against chassis? Tighten mounting screws - check
standoffs.

 Are there components touching the turret board? Use a chopstick to prod some of the
larger ones first, then space them off the board; You can even silicone the rattling parts to
board if necessary (especially larger caps).
 Are there Components touching each other? Use a chopstick to prod some of the larger
ones first, then separate them; Silicone the rattling parts to separate them (especially larger
caps)

Other Tests
 Try different tubes - if it is coming from both channels, try output tubes first. Tap them
when removed from the amp to see if you can hear any rattles.
 Input/Output jacks - try plugging a spare 1/4’ jack into the other jack(s) when playing or
the end of a chopstick. Replace the noisy jack.

 Speaker - vibration between alnico magnet & bell cover; or voice coil rub. Try a different
speaker; Replace speaker if necessary

 If you have a signal generator you can sweep from a low frequency noting where any rattles
occur. Then leave the frequency generator at that position while you prod around looking
for the source of the problem. Fix it and move on to the next one. If you don't have a
signal generator, then you'll need to pluck certain strings of your guitar in sequence and see
what excites the rattles.

At three separate and different frequencies you might find:
 Components vibrating against the board;
 Chassis rattling against the cabinet; and
 Mechanically noisy tubes (V1 for example).

Make sure all the components are away from the board and not touching, and put neoprene 3/8’
X 1/8’ window sealer with one adhesive side, between chassis and wherever it touches the cabinet.

TrinityAmps TRIWATT Builders Guide Ver. 2.31.docx
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