5E3 too clean, no distortion

[loudthud]

The schematic that Chuck H posted is the one I used that gave me lots more breakup. To reduce the signal, it looks like I could increase the 2M2 or decrease the 1M? What would be the difference between those two approaches?

The parallel combination of the resistors acts as a load on the previous stage. As long as you don't go too low, (below 500K) the attenuation will be less than 1dB (10%).

[6v6Pin1]

It would help to know where the extra clipping is happening. Is the PI bias skewed such that it's being clipped more or is the new PI configuration putting out more swing so that you are getting more power tube clipping.?.

This is currently above my pay grade. Would I need a scope for this?

This description is similar to what I have read from multiple sources:
What the "Paul C" mod does for the player. - Lil Dawg Amps
"The 5E3 is known for very it’s early volume increase & break-up, so at about 3 you are at full on overdrive with about max volume and everything after that is just more drive and saturation." This quote describes my amp after the mod. Before the mod, my amp behaved as described in this thread. But, I don't know for sure what a correct 5e3 sounds like.

[Dave H]

...It would help to know where the extra clipping is happening. Is the PI bias skewed such that it's being clipped more or is the new PI configuration putting out more swing so that you are getting more power tube clipping.?.

I measured it a while back (see below). With 2M2 the output of the PI at the onset of PI clipping was about 44V p-p (22V peak). With 4M it was 110V p-p (55V peak). My amp needs 27V peak at the 6V6 grids to drive it to full power so you can see that with 2M2 it would not be driving to full power. If 6V6Pin1 prefers it like that I wouldn't want to change it. To check he could try changing the 2M2 to 3M9 but I expect it would then sound exactly like the stock circuit.

[Dave H]

"The 5E3 is known for it’s very early volume increase & break-up, so at about 3 you are at full on overdrive with about max volume and everything after that is just more drive and saturation."

The "early breakup" of the 5E3 is because the volume controls are wired 'back to front' which destroys the log taper of the pot making it effectively full volume at 3. It's only "early breakup" in the sense that it starts early on the vol pot scale but it still doesn't breakup below full power output. It won't do "early breakup" in the sense of breakup at low speaker volume. If the vol pots were wired in the coventional way without changing anything else in the circuit they would function as normal log pots and breakup would start at 7 or 8 on the dial not 2 or 3.

[pdf64]

The Lil Dawg page What the "Paul C" mod does for the player. - Lil Dawg Amps describes very extensive changes in the amp's response, eg

The Paul C mod will give you more headroom so the overdrive wouldn’t come into play until you are at about 6-7 (tweeds go to 12), but after that it’s overdrive as normal. It also gives you more of a traditional volume increase instead of that very early ramp up, the tone control acts more like a traditional tone control, and the bottom end gets tightened up as well as getting a giving you a bump in volume

I suspect they are doing rather more than just putting the cathodyne into fixed bias, eg also implementing 6G3 style vol / tone arrangement, reducing coupling cap values.

[fdesalvo]

I had more hair on my head the last time I saw this thread.

[Enzo]

Hair? What was that like? I've forgotten...

The above poster just spammed another thread for a CHinese guitar and amp maker.

[Chuck H]

T took care of it I think he sits at the computer cleaning and polishing his gun