72 Marshall Aritste'

[Baxtercat]

Man, that thing looks good. That pseudo Bluesbreaker w/ checker cloth look is their sexiest design, imo.

[Reeltarded]

channel 2 has a weird distortion when playing low root and 5th's at all volumes. I don't have the reverb hooked up but that shouldn't make a difference.

only mods I can see are bypass caps added to ch 1 cathodes and one on ch 2 1st gain stage.

Awesome it lives!!!

I suspect DC on the 2nd channel at the PI. It's a wag, but I like to gamble.

[randalp3000]

channel 2 has a weird distortion when playing low root and 5th's at all volumes. I don't have the reverb hooked up but that shouldn't make a difference.

only mods I can see are bypass caps added to ch 1 cathodes and one on ch 2 1st gain stage.

Awesome it lives!!!

I suspect DC on the 2nd channel at the PI. It's a wag, but I like to gamble.

Leaky coupling cap? hope it's not one of those mustard's. I hope to go through and check the voltages tonight.

Good lord I hope I don't get on a Marshall kick....... I have 2 old Mojo jtm45 kits that might need rebuilds as a jtm50 or super lead..

[randalp3000]

Man, that thing looks good. That pseudo Bluesbreaker w/ checker cloth look is their sexiest design, imo.

I concur, thanks. almost get a chubby when I look at it.

[old tube]

Well, this is a bit spooky! Check out the QC label on mine below ... made on the same day in Nov. 1972.

I got it very cheap about 4 years ago. It had been pretty heavily modded when I got it, someone had tried to make it into a JTM45 and failed! Most of it was still there and put it back to stock using an old Selmer PA amp as donor for mustards etc.

I am never sure about this amp, love the look, and sometimes it hits the spot for the sound I want. But it's a bit of an enigma as a Marshall. I find the reverb pretty lame and that channel is low volume as well due to the large resistor in the reverb circuit. The dry channel on mine I find very dark, unless it is close to dimed ... however, at that point the amp comes alive and is full of Marshall crunchy goodness.

The only mod I've gone with is to put the Reverb on a Push/pull pot which simply takes the reverb circuit out. With the Channels linked with the reverb out .. it is definitely much more like the thing. My '68 JMP 50 it is not, but it's still a good Marshall.

Suppose I've kept it because of how it looks and keep thinking one day I'm going to build a Trem 50 and use the cab and speakers to host it.

[randalp3000]

Wow twins.....
channel 1 on mine is not dark at all, it will tear your head off. Someone added a .68 bypass cap on V1A and I think a 25uF on V2B.


Still have the distortion on reverb/ch2, it distorts on lower notes at low volume. I checked all the voltages and they are all within 5-8 volts to the chart. I also looked for leaking DC on the coupling caps.

If anyone has any ideas please let me know, I don't want to start tearing it apart yet.

thanks
rp