Mods

[tshodges]

I've created an updated post. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[OnTheFritz]

Maybe post a pic of the innards, and people can help you from there. From my understanding, there's ribbon cables etc, like a PC, so a picture is worth a thousand words.

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[neikeel]

Sorry cannot find a schematic or parts layout for one of these.

Need to locate the phase inverter caps and the grid resistors for them (and the resistor values) , once you do that need to decide where the pot can go.

What features does the amp have now - no MV?

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[neikeel]

I am pretty familiar with the 1959 schematics over the years

It is difficult to see what part is located where on those pcbs.

I can make out the preamp section with the board mounted B9 sockets. The one nearest the switches will probably be the phase inverter. You are looking for the PI out grid resistors (usually 220k on an NMV Marshall with EL34s) these can be 82k to 220k depending on the output valves being used. A close up photograph of that part of the preamp pcb might help so that I can see the components, their values and where the traces go, not easy from the pics we have so far.

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[toner]

It's impossible to tell how to add the MV from those pictures. You really need a schematic or take it to a local tech.

I'm pretty sure the PI socket is the one on the right labeled "V5" so the connections of interest should be around there. There's a good chance that the PI output caps and the bias feed resistors are not directly next to each other on the PCB. You'd likely have to do some continuity and voltage tests to locate them without a schematic.

[robert]

Simply find a serious & good tech, get the layout & the schematic from Bugera or their distributor, and voila!

Because it's a very simple amp with absolutely no secrets inside, and since Bugera claims to be a professional manufacturer, there should be no problem to get the layout and the schematic.

Regards

Robert

[tshodges]

I've created an updated topic. Please check out: "Connecting the Lar/Mar in a Bugera 1960"

[neikeel]

It would be easy to talk you through it with a schematic