Skip to main content

RD one hundred getting it's brains cloned

Aw shit! What have I done here....

Looks like I've gone down the deep rabbit hole of repair and amp modding on my friend's MM...

Full Name
Rob Flindall
Music Man Equipment
112RD-100 with EVM speaker, built 1981

Member for

10 years 8 months

RD112 Sat, 04/18/2020 - 10:31

The image is blurry...but that looks like a nice clean representation of the schematic. Is it downloadable?

Full Name
Karl Schmitz
Music Man Equipment
I'm only the drummer so I don't own anything... Buuuut my guitar player has a 112 RD 100 that I keep fixing.

Member for

6 years 5 months

G60syncro Sat, 04/18/2020 - 12:53

In reply to by RD112

Indeed, it's just a copy of the GD-2 board from my friend's RD100... The original .gif file was a bit hard to read and also I wanted to have it linked to my PCB layout in KiCAD to make sure I had everything wired up properly. Basically, my friend's amp is fried and I'm cloning the PCB to make it run like new again!!

Full Name
Karl Schmitz
Music Man Equipment
I'm only the drummer so I don't own anything... Buuuut my guitar player has a 112 RD 100 that I keep fixing.

Member for

6 years 5 months

G60syncro Sun, 04/19/2020 - 09:42

There, I think this looks alright... You guys let me know what you think! There might be some annotations to clean up here and there, but it's already way more legible that the scan of the original one!!

Attachment
Attachment Size
RD100-112.pdf (271.92 KB) 271.92 KB
Full Name
Karl Schmitz
Music Man Equipment
I'm only the drummer so I don't own anything... Buuuut my guitar player has a 112 RD 100 that I keep fixing.

Member for

6 years 5 months

G60syncro Wed, 07/15/2020 - 21:26

Well... looks good... let's see how it sounds!!

Images
Full Name
Karl Schmitz
Music Man Equipment
I'm only the drummer so I don't own anything... Buuuut my guitar player has a 112 RD 100 that I keep fixing.

Member for

6 years 5 months

G60syncro Sun, 12/06/2020 - 13:09

Okay, I know it's been slow here... After I posted the picture of the assembled board I got into a garage building project and moved all the stuff from my old place into it! Then I ran into the issue of not being able to buy the breakers needed for the workshop which caused further delay... Anyhoo, I'm back and happy to report this thing is back to being sweet sounding!!

With the new workshop setup, I was able to get some shit done and first on the order was getting the Musicman box out of storage and running some unpowered signal tests on the board itself. First off I was having a trouble with this not having any gain when powered... It was traced to an opamp having one side of it's pins wedged between a cap an the socket rather that in the socket proper. Once resolved, I powered up the amp once more and then it was alive!! Virtually no hum and that's with a Tele plugged into it without the chassis properly shielded and the filter cap doghouse off. I can't wait to get it back to my friend this week for a proper test and hopefully a sound clip!!

Also, I need to fix an error on the schematic... where the shielded cable connects to the impedence switch, it's on the wrong pin on my copy of the schematic.