Converting JCM 800 PCB to SuperLead PTP

Dax-The-Ax · Post by **Dax-The-Ax** » Mon Oct 04, 2004 8:10 pm

Hello Everyone,
I am thinking about converting my 1986 JCM 800 100-watt to a PTP Superlead. This JCM 800 has the PCB mounted pots and three filter caps. Does anyone have any comments or suggestions? I am just wondering if the wiring is going to be different with only three filter caps, etc.
Any advice is welcome.

Post by **VelvetGeorge** » Mon Oct 04, 2004 8:22 pm

Dax, what are the values of the filter caps? This swap will be a little more involved, but still very doable.

George

Dax-The-Ax · Post by **Dax-The-Ax** » Tue Oct 05, 2004 2:16 am

There are three 50uf x 50uf 500 Volt Filter Caps. Goerge, would you rip the effects loop out and leave it bone stock Superlead? the amp has serious power, it probably will sound Huge!! I can't decide.

Dax-The-Ax · Post by **Dax-The-Ax** » Wed Oct 06, 2004 1:40 am

Hello, George?

Post by **VelvetGeorge** » Wed Oct 06, 2004 3:58 am

Hey Dax, I was out of town all day. I just got home about 3:30 AM. I'll try to reply to this tomorrow.

George

Dax · Post by **Dax** » Thu Oct 14, 2004 2:55 pm

Hello, George!! It's not like you're Busy!! Ha Ha!! Just kidding. Did the JCM 800 1959 Version have only 3 Filter Caps, i think they did.

Post by **VelvetGeorge** » Thu Oct 14, 2004 5:01 pm

Dax, I don't know for sure. These may be the non-voltage doubler type. That would account for a couple filter caps.

Can you take a pic of that amp?

George

Dax-The-Ax · Post by **Dax-The-Ax** » Thu Oct 14, 2004 7:05 pm

OK kids, here are some pics of my raped Red JCM 800 2203. It has been modded and flogged, added gain, effects loop. So i think i'm going to go to Metro PTP 1959 Specs and i'll probably leave the FX Loop, since it's already there. If theres any other pics you want George, let me know.

Dax · Post by **Dax** » Thu Oct 14, 2004 7:29 pm

Maybe i'll just send the amp to you, George. The wiring nightmare worries me a bit. You could install the PTP Superlead board and add a pretty FX Loop Board. Might be a fun experiment for you. I don't know if you've converted a JCM 800 yet.

Necrovore · Post by **Necrovore** » Thu Oct 14, 2004 7:55 pm

Dax wrote:Hello, George!! It's not like you're Busy!! Ha Ha!! Just kidding. Did the JCM 800 1959 Version have only 3 Filter Caps, i think they did.

I have the 800 series 1959 model and yes it only has three filter caps.

Flames1950 · Post by **Flames1950** » Thu Oct 14, 2004 10:35 pm

OMG, that should scare you. What a clusterfuck. Definitely needs a wave of the MetroAmp magic wand.

Country Boy Shane · Post by **Country Boy Shane** » Thu Oct 14, 2004 11:14 pm

Right you are. Definitely looks like a gang-band compared to the MetroAMP's we are used to seeing. Have fun with this project man!

Dax · Post by **Dax** » Fri Oct 15, 2004 12:11 am

You should have seen it before, it was caked with white and black "Goo" covering up the modders great secret creation!!! It looked like someone took a shnoods on it. George cleaned it up for me. The printed boards just suck. I think Marshall just used cheap components when they couldn't get the "Mustards" anymore. I swapped the board in my 76' and it was night and day!!

Flames1950 · Post by **Flames1950** » Fri Oct 15, 2004 8:40 am

What great secret was the goo covering, the fact that he forgot to wire up an entire preamp tube socket?!?

Reminds me of that old thread showing early VooDoo Amp mods.

Dax · Post by **Dax** » Fri Oct 15, 2004 11:58 am

The Pre-amp socket was a gain mod that i took out. Even the components were covered in black ink to hide the values, how ignorant!!

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Converting JCM 800 PCB to SuperLead PTP

Converting JCM 800 PCB to SuperLead PTP

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