Dual Recto - Rev. G to Rev. F Conversation Help.

[Luke Gibson]

I’m looking for schematics or a list of the differences to mod my early Rev. G Dual Recto. I’ve looked through a bunch of threads on here and the internet but haven’t found anything. Can anyone point me to any information that would help? Not concerned about converting the loop to Serial. Thanks in advance!

 

[meesa_jarjar]

hope I'm not necro-ing.
you want to start with the gain control circuit between the V1a and V2a as shown on the Rev F schem. I do not know of a specific schem that shows the differences, but working from memory, there's adding 2.2meg resistor to ground coming right off the coupling cap from the plate of V1a, and then changing out the 250k gain pots for 1 meg.
I would also verify the presence values by comparing them with your amp vs the Rev F schem. on the red channel, the presence circuit consists of a resistor, cap, and pot, all inline with each other, in parallel with the channel MV.

 

[Luke Gibson]

hope I'm not necro-ing.
you want to start with the gain control circuit between the V1a and V2a as shown on the Rev F schem. I do not know of a specific schem that shows the differences, but working from memory, there's adding 2.2meg resistor to ground coming right off the coupling cap from the plate of V1a, and then changing out the 250k gain pots for 1 meg.
I would also verify the presence values by comparing them with your amp vs the Rev F schem. on the red channel, the presence circuit consists of a resistor, cap, and pot, all inline with each other, in parallel with the channel MV.

Thank you for the reply, I appreciate the information!