Lars Verholt (lmv)
I recently rescued an RD-50 110. The poor thing came to me without the speaker, shot reverb tank and some bad cross-over distortion. During the repair process I discovered that the amp is a version not documented by the schematics found on this website. It has 27 ohm cathode resistors and the base bias voltage is derived by a 43k resistor from the 30V grid supply (one for each transistor). Does anybody have a schematic of this type? Would be cool to have it properly documented.
|Bill Traylor (bozzy369)|
Lars,I may be wrong but it sounds like you got one of those in between proto-type models.There was a period where musicman hired new designers and tinkered with the layout of the circuits.You seem to be a pro at working on this kind of stuff.So, If I had to work on this thing I would use the schematics from this site and replace all the different inprovements they tried to make.Then if you want to make that head better Ed Goforth has tons of great mods and ideas for it ,best of luck,Bill
|Lars Verholt (lmv)|
thank you for the quick response and thanks for confirming my thought that this is an 'odd-ball' version. For general info I should mention that the new speaker I put in the amp is an Eminence Copperhead. Although I am not much of a 'mod' guy, I am considering making a change in the circuit to have the bright control on the footswitch instead of the reverb (which I always leave on anyway).
All the best,
Tue, 03/25/2014 - 09:32#1