Randall mod

[Phil]

Hello does anyone have any experience with old randalls ?

[Phil]

I have a randall rg80 that someone has modded. It has 4 1/4 inch jacks installed on the bottom. The wires from these jacks run to the master volume pots on each channel and to the board. I've tried to post a pic but it won't let me for some reason

[Tortuga]

Best way to post pics is to use an image host, like imgur, tinypic, etc. One you upload your pic, get the image link (preferably the one for posting on a forum), and paste into your posting here. The link should be surrounded by "img" & "/img" (in square brackets) - if not, add them.

[ajaxlepinski]

Welcome to the fold brother! This is the best guitar/amp forum on the interwebznet!!!

What do you want to do? Restore the amp to the original condition?

What does the mod do? My guess is that the jacks can connect to an expression pedal so the volume can be controlled out front?

Been playing my 1980's RG80 for over 25 years... fantastic amp.
I like it soooo much, I bought a second 1980's RG80 to use as a backup, in case I fucked up making my own repairs on the first amp.

... and thank you for the opportunity to post some pics!!!
Mid 80's gut shots. The first run of RG80's had witch hat knobs.


The late 80's intenstines:


Front and Back. The one labled "Old RG80" was my first purchase and was a late 80's version. The one labeled "new RG80" was the second RG80 I bought about 2 years ago - it was made in the early part of the 80's.

[JSutter]

Here's my guitarist's RG 80 ES. I flipped the head shell, added the lights and made a foot switch.

[ajaxlepinski]

^^^ That's a good one! Higher values on the components than other RG80's ^^^

[JSutter]

^^^ That's a good one! Higher values on the components than other RG80's ^^^

I always wondered the tone difference. Good? Bad?

Are you familiar with older Randall's? I have an RG 140 112 that might need pots. I'm looking for pot values to fix it and some direction on what pots fit. They are pcb mount.

[ajaxlepinski]

^^^ That's a good one! Higher values on the components than other RG80's ^^^

I always wondered the tone difference. Good? Bad?

Are you familiar with older Randall's? I have an RG 140 112 that might need pots. I'm looking for pot values to fix it and some direction on what pots fit. They are pcb mount.

I suppose it's all subjective but, I like the "late 80's non-witch-hat-knob RG80's" better. They sound a bit beefier and a little less shrill, than other RG80's. Possibly, because the higher value caps allow more low end through? The difference is noticeable for me because, I've been playing mine for over 25 years - most people won't notice or care.

Not sure what replacement pots to use on your RG140. Identifying pot values is another thing I need to learn if I am going to earn spare money doing repairs.
I'll see if I can find a schematic with the values.

One suggestion: if you can, clip the metal pot leads off, as close to the pot as possible. This will leave tabs (on the PC board) to solder connecting wires to the new pots. It's easier to take the PC board in and out if the pots have wire leads instead of being soldered directly to the board. You can also desolder the pots and simply solder wires into the board.

You can see my pot wires, soldered to the board, in this pic. The wires really make pulling and reinstalling the board easier.

[JSutter]

Thanks for some insight. I looked for a schematic but only found the manual.

I pulled the board and measured the pots with my meter. One side reads around 3.xx k; the other side is 9.xx k. I figure it must be a 10k pot. I know something is wrong because it is rather loud with the volume on 0.

I think I came across the amp in the original post on Ebay. It's a strange mod. They cut out a bit of PCB to make room for the jacks. Could be some sort of bastardized loop for each channel. Seller is hardvalve1, same dude on here? https://www.ebay.com/itm/Randall-RG-80- ... true&rt=nc