I just finished wiring up a 5E3-based head build late last night. I had shared a couple of photos in one of the recent work in progress threads, and wanted to share the results.
I had bought a Classictone 40-18066 upright PT (330-0-330 secondary) and 40-18022 OT (8k:8ohm) when it was announced that Classictone was stopping production. I chose to mainly use metal film resistors as an experiment. I used three 22uF filter caps, since that seems to be the recommended modern setup. All installed in an oversized Hammond 1444-22 chassis, so I could also add a Hammond vented cage for that lunchbox amp look.
I mainly used the Rob Robinette’s 5E3 page and old posts from this forum as reference to wire it all up. I split the power grounds from the preamp grounds based on Rob’s modern 5E3 layout.
I only checked the voltages at the filter caps: 382V, 329V, and 241V from a wall voltage of 121V. I used JJ 5Y3 and 6V6 tubes in the power section. I didn’t measure the tube pins because of the excitement of having an operational amp at power up. I may investigate lowering the B+ in the future. Any suggestions or links to old threads would be appreciated.
I finished my build at around midnight, so I had to test the build out through a Suhr Reactive Load through impulse responses. In the clip below, I played a few open chords on a guitar equipped with a GFS Mean 90 bridge pickup. I used IRs of my speakers: Weber Ceramic Blue Dog in a 1x12, Eminence GA10-SC64 in a 1x10, and finally a Jensen C10Q in a 1x10 cab. Tone was maxed, and the bright volume was at 12:00.
The main mod I added was switchable NFB: a pot in series with a resistor to go from 27k to ~47k. I haven’t tried this out yet, and experiment with getting that NFB resistor value up to 56k in the future.
I had bought a Classictone 40-18066 upright PT (330-0-330 secondary) and 40-18022 OT (8k:8ohm) when it was announced that Classictone was stopping production. I chose to mainly use metal film resistors as an experiment. I used three 22uF filter caps, since that seems to be the recommended modern setup. All installed in an oversized Hammond 1444-22 chassis, so I could also add a Hammond vented cage for that lunchbox amp look.
I mainly used the Rob Robinette’s 5E3 page and old posts from this forum as reference to wire it all up. I split the power grounds from the preamp grounds based on Rob’s modern 5E3 layout.
I only checked the voltages at the filter caps: 382V, 329V, and 241V from a wall voltage of 121V. I used JJ 5Y3 and 6V6 tubes in the power section. I didn’t measure the tube pins because of the excitement of having an operational amp at power up. I may investigate lowering the B+ in the future. Any suggestions or links to old threads would be appreciated.
I finished my build at around midnight, so I had to test the build out through a Suhr Reactive Load through impulse responses. In the clip below, I played a few open chords on a guitar equipped with a GFS Mean 90 bridge pickup. I used IRs of my speakers: Weber Ceramic Blue Dog in a 1x12, Eminence GA10-SC64 in a 1x10, and finally a Jensen C10Q in a 1x10 cab. Tone was maxed, and the bright volume was at 12:00.
The main mod I added was switchable NFB: a pot in series with a resistor to go from 27k to ~47k. I haven’t tried this out yet, and experiment with getting that NFB resistor value up to 56k in the future.