Musicman RD-50 112 mod

[Enzo]

Hi joe, welcome

This thread has been dead for 13 years, may I suggest you start a new thread for your amp.

A start might be to open R19.

Converting the reverb to an FX loop would not be for a novice.

[joedonchev]

Thank you! I will start a new thread

[czech-one-2]

All,
I'd like to share some of the mods I did to smooth the harsh top end of the Limiter channel typical for Musicman amps. In general, changed the V1a and b stages per the *umble OD stages.
In Particular:
1. disconnected the cathode grounds and ground leads from C10,R12 at V1-8.
2. Added a 5uf and a 1.8k at V1-8 and connected the grounds to the C10,R12,ground node.
3. replaced plate resistors R9 (470k) with a 180k, and R11 (4.7M) with a 150k.
4. replaced R10 with a wire jumper.
5. removed grin wire at V1-7 and added a 150k series grid resistor.

Initially also added a 470pF across the Clean Vol pot, and a 1000pF across the Limiter Vol Pot to smmoth the harshness at all vol levels in either Clean or Limiter mode.
The amp is much more useable and it definitely earned it's keep at last weekends gig. BobW

BobW, if your still around THANK YOU!
I finally got around to these mods on the RD-50's 12ax7 and the limiter channel sounds great! The flabby mud is gone and I'm getting a great blues to crunch tone with much more articulation and clarity.
In your post above there is no mention of removing the .047 C6 cap to ground, but in the 'mod' schematic it is removed?
I left it in and have zero complaints, the limiter channel sounds outstanding. Just wondering if you advise removing it and what the effect of this cap to ground has?
Cheers !!!

[g1]

In your post above there is no mention of removing the .047 C6 cap to ground, but in the 'mod' schematic it is removed?

The 'mod' schematic from the previous page is no longer available. Could you re-post it here? Thanks

[czech-one-2]

The 'mod' schematic from the previous page is no longer available. Could you re-post it here? Thanks

Thanks for the reply! Really, this mod is Golden! Day and night difference on the 'limiter' channel. (Who named that anyway? Leo? ;-)
By the way, I didn't put a cap on the limiter volume pot or convert the bright switch to a boost/mid shift. I rather like the bright switch. And also, I have two of these amps [yes I like them ALOT] so did the mod to both. Pulled C6 on one and didn't really hear any difference.