JCM800 split channel mod Ottovalvole

[otto]

For one Are the letters, such as "A" were the lines just stop will I make a connection to a solder pad or trace there and the then trace goes to where the other "A" is?

"A" connects to the other "A", B to B and so on. I've used letters only because there was no enough space on the original schem to draw the adds.
It's a representation only, it's not important how you make it, you can use a wire soldered point to point. For a portion of the circuit I've used an additional little board with components connected point to point and then point to point to the master board.

I am also not sure where you have cut the board. It looks like the reverb is cut out of the signal switching. Will I still be able to turn the reverb on and off with the foot switch?

The reverb circuit varies in different versions of the jcm800. I've drawn it only to represent mine. Don't touch it if you havn't problems with it. It's not important in the resulting sound. You are still in time to mod it later, in case.
I've cut the circuit of the board in the zone of the double pot of crunch channels's gain. This means that if you want to go back with the mod you must reconnect the 2 parts with a wire.

Also I to am having trouble reading a lot of the values are you sure you can't just make a parts list? Also is there additional information on the hand drawn schematic? It looks incomplete to me and I don?t know what the "TS" with a circle around it means.

You can check values with the hand drawn schem. If you have doubts with a particular value ask me.
The hand drawn schem is a semplification of the important part of the mod, the one that gives the crunch channel. TS is for "tone stack", it is the tone section, you can find it on the other schem. As first job you can leave it as it is and change it in a second moment if you don't like it.

Also what wattage of resistors will I need and do you suggest metal film caps and resistors like with effects pedals?
Thanks Alex.

Resistors are half-watt (1/2 watt), metal films are ok. Capacitors 400V. For "sound" of different types is the same as for pedals, I think the mod is far more impostant than their material.

Go with the hand drawn mod first and try it.
Let me know ...

[otto]

I suggest other 3 little mods to prevent possible noise.

1) 47 pF capacitor between cathode and anode of V1a, soldered directly on the tube socket.

2) 470 pF capacitor in parallel with 150k anode resistor at V1b

3) 22 nF capacitor in series with the 220k resistor in the clean channel tone stack. If you don't change your tone stack values leave the resistor you have but add a 22 nF cap in series with it if it is not present, if it is present leave the one you have as first attempt

[Sandfobs]

Hey Otto hoping your reading this quickly I have my tech guy doing the mod right now, Im hoping if there is any problems your here to help me walk through. Thx in advance.

[The Dude]

FWIW: otto hasn't logged in since 2011.

[Sandfobs]

Well let’s see if we can awaken the dead, by the way this amp was sounding live it could have. Lol