6g2 blocking distortion at high volume

[sluckey]

I am beginning to think that I am expecting too much from this circuit. I am testing this out with an attenuator at full on volume with a full shred pickup. With no attenuator, I get very loud and clean tones past the halfway point. I know it's an old fender design and I'm looking for smooth marshall grind out of it. I'd like to try the zener trick to equal out the Cathodyne balance

I agree. This amp was never designed for what you expect. The 6G2 was a small modest parlor size amp with a student/beginner in mind at a time when Marshall grind was unheard of. Clean with a bit of tremolo, but not loud.

You may get close to the sound you want but don't try to make a silk purse out of a sow's ear.

[audiosalvage]

One last question though, I built an Express last year and it had a very high and strong B+ which made it stay clean until excruciating volume. My PT has a dual tap, now if I would use the higher one, could this cure the issue?

[audiosalvage]

Yeah I don't want to make it what it's not, I want to make it perform like it should.

[didit]

Hello --

Suggest a close review of the cathodyne PI modifications that Dumble used on the Tweedle Dee. Well documented across a few threads here.

Maybe start at this and work backwards :: https://ampgarage.com/forum/viewtopic.p ... &start=315.

..

[maxkracht]

One last question though, I built an Express last year and it had a very high and strong B+ which made it stay clean until excruciating volume. My PT has a dual tap, now if I would use the higher one, could this cure the issue?

You would get more volume, but probably not a whole lot more. More overall voltage isn't going to stop the PI from distorting so tending to that is probably a better move. If you do change the B+, make sure your output tube's plate, screen, and corresponding filter caps can handle the extra voltage. You might need to check the datasheet on your specific output tubes.

[LOUDthud]

I built an Express on a Traynor YBA-1 chassis. It was unruly and harsh until I lowered the B+ down to 400V. That was the sweet spot.

[audiosalvage]

Ok I tried the higher PT tap and it may be a smidge louder but same tone over all. I'll stick with the lower. I will experiment with the grid stopper values and be done. I think a little fuzz at the end of the volume travel can be kind of useful, so long as it doesn't cut out. Thank you all

[audiosalvage]

NOW were talkin'! I put some 47k grid stoppers in and I'm happy with the results. full vol has a little saturation and backing it off a bit gives a rich, warm edge. With the tremolo on, it can do "Born on the Bayou" perfectly. Time to put her in a cabinet. Thank you all again.

[audiosalvage]

Here is a clip of the range of this thing. Strat with SD mini in the bridge and no pedals

[audiosalvage]

Here is a photo of the final product