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Tremolo Depth

1/17/2006 10:19 PM
A.J Tremolo Depth
Is it possible to get more tremolo depth out of a AB763?
1/17/2006 10:33 PM
Rick Erickson

Sure - you can change the "roach" or roll your own. I used to get the LDR's (and neon bulbs) from Mouser but they quit carrying them. Most all of the "roach replacements" from the usual suppliers failed to meet my requirements. You can even convert the trem to a bias modulation type that affects the power tube bias. I think there's some fender circuits that could be addapted to your amp to do that. Would require some homework/research though.  
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1/18/2006 2:16 PM
Checkout the tremolo ckt in the Vibroverb schematic, it may be just what you are looking for. One of the coolest tremolo, in IMO is the Kustom ckt. Everytime I hear it it reminds me of John Fogarty. BobW :-)
1/18/2006 6:25 AM
I have a Quad Reverb I reverted to BF AB763 specs:  
The tremolo seemed weak to me when I finished the mods so I ordered and replaced the trem bug, dunno where I got it, maybe Hoffman? Anyway it made a huge difference, it now has a huge amount of depth.  
BTW, modding the trem circuit to make it switchable in and out is a cool easy mod for these Fenders. I did it on the Quad and my Bandmaster too.
1/18/2006 7:33 PM
Thanks guys but the culprit was a bad LDR. Had some old ones from past repairs. Kept them for spare parts.Finally came in handy. It's got depth now, think CCR!
1/18/2006 7:41 PM
Greg Simon
With the roach type trem, another way to increase depth is to move it's injection point into the amp to an earlier circuit point in the amp. So after the first stage for example instead of after the reverb recovery/mixer stage.  
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