The Amp Garage

Some time back a joostin posted some mods and a schematic that also included some mods by BOBW on a Music Man RD50. One of joostin's mods was to insert a PAB switch between the bass and treble pots. I have been told it's possible to replace R8 with a 25k pot to create variable PAB. My question is ca...

Current issue JJ 6L6, EL34 or 6CA7 no problem, Sovtek 5881 not a problem as well. TM[/quote] Thanks ToneMerc, for the suggestions on the caps. Regarding the tubes you listed, would rebiasing be needed on these? I currently have the original Sylvania 6l6's in it. By the way I sent you a pm. Please le...

Thanks Stevem! I remember that this amp runs a high voltage to the plates. JM, I don't have the specs for the transformer but a little background. I bought the amp new in the early 80's and it has never been out of my site. It has the original Sylvania 6l6's and likely has never been abused. As amat...

Thanks much JM! I'm no cork sniffer so I thought I would ask! Do you think there was any other purpose? Would it reduce hum at all? While I'm asking, in order to calculate the plate voltage I need to know the PT specs correct? Anyone know where I can find those? I would like to make sure I know what...

I would appreciate some inputs on a cap question please. Few years back Jooshtin posted a schematic with BobW's mods as well as some he came up with for the MM RD50. Specifically some changes were made to the ,I believe supply caps, C33,34,35. These are intended to tighten up the bass, correct? Will...

Thanks Silverfox! I already have the schematics, and the post from Justin. I'm hoping to have BW contact me so I can discuss his mods.

I'm actually trying to get BobW to contact me regarding his very old music Man RD50 mods. I tried pm but I know he recently had a "spam" attack and may be reluctant respond. So, If your out there please pm me I have some questions. Thanks!

My mistake, I will try to make my posts more clear in the future. Actually MFowler, I was not being lazy as I had already bookmarked the TweedleD-Mod (Thank you Charlie Wilson) schematic prior to posting my question. That you are correct would have been unbelievable in it self. It did appear that se...

I know there are several threads regarding the KWS (Dumble) style tweed deluxe, but is there an actual schematic that is generally accepted or used as an accurate blueprint? Or is everyone using their own "take" on what has been published?

I know Dumble used a Ratio Control on some amps. I imagine that this is understood by most here but I would appreciate being pointed towards previous discussions about this concept and related schematics. The only thing I can find is that it's purpose is to feed a portion of the overdrive signal int...

Thanks for the link! After looking at the schematic and reading BobW's description of the mods I have some questions that I hope someone can answer. I have pmed BobW and emailed Jooshin with no response, (guess they may have moved on). BobW's description of the mods from another post on another foru...

Morning, I have a MMRD50 that I would like to mod the limiter channel on. I have seen some old threads that discuss this type of mod and indicate schematics are attached but have not been able to view any of these. BobW and Jooshtin to drop a couple of names. Could some one please direct me to the s...

Thanks M, I thought I had gone through all of them but I guess not. Thanks again!!

Very late to the party but I would much like a schematic and layout for the Airbrake! I intend to use with a MM112RD50. Please P.M. and I will send email.
Thanks much!