thecr4ne wrote: Mon Aug 21, 2023 11:21 am Ok, I finally got a chance to dig into the Pignose G40V yesterday as I weathered the weather here in southern CA. And I have a new issue. It sounds like there's a very faint high gain version of the signal mixed in with the actual signal. It's not a hum or a buzz, it doesn't happen when the guitar's not playing, and it's very quiet compared to the actual signal, but it's definitely there. Any thoughts?

Here's what I did:

I swapped out the input jack and added the 68K resistor there, Removed C9 and C21, swapped out R2 for a 100K pot for adjustable bias added 1 ohm resistors to pin8 on power tubes for bias measurement, and swapped out the olde chinese 6l6GC's for some NOS Jan 5881's I had around. Re-biased to about 34mA on each output tube.

Put it all back in the cab, fired it up and plugged in a guitar. Sounds great! Then...POP. (shit)
Switched it off immediately. Oh crap did I blow a filter Cap?

Opened it back up, turned it on again to inspect, and saw some fireworks under the PSU board. Pulled the board off the standoffs and suspended it to have a look at the underside and tried again. Turns out the power supply was arcing between traces on the PCB. Nice little burn mark (sorry didn't take a pic).

Called my olde man to discuss solutions, and after that consultation scraped off all the carbon from the scorch mark, and applied a coat of readily available brush on lacquer called "nail polish" (thanks wifey). It was even green, though not quite PCB green. Anyway I touched up the scorched spot with about 4 coats in total, and a few other spots that looked like the trace might've been slightly exposed just in case.

Fired it back up and no more fireworks. Cool. Still have the faint sympathetic signal though. Not sure where to start troubleshooting that.

thecr4ne wrote: Mon Aug 21, 2023 11:21 am Ok, I finally got a chance to dig into the Pignose G40V yesterday as I weathered the weather here in southern CA. And I have a new issue. It sounds like there's a very faint high gain version of the signal mixed in with the actual signal. It's not a hum or a buzz, it doesn't happen when the guitar's not playing, and it's very quiet compared to the actual signal, but it's definitely there. Any thoughts?

Here's what I did:

I swapped out the input jack and added the 68K resistor there, Removed C9 and C21, swapped out R2 for a 100K pot for adjustable bias added 1 ohm resistors to pin8 on power tubes for bias measurement, and swapped out the olde chinese 6l6GC's for some NOS Jan 5881's I had around. Re-biased to about 34mA on each output tube.

Put it all back in the cab, fired it up and plugged in a guitar. Sounds great! Then...POP. (shit)
Switched it off immediately. Oh crap did I blow a filter Cap?

Opened it back up, turned it on again to inspect, and saw some fireworks under the PSU board. Pulled the board off the standoffs and suspended it to have a look at the underside and tried again. Turns out the power supply was arcing between traces on the PCB. Nice little burn mark (sorry didn't take a pic).

Called my olde man to discuss solutions, and after that consultation scraped off all the carbon from the scorch mark, and applied a coat of readily available brush on lacquer called "nail polish" (thanks wifey). It was even green, though not quite PCB green. Anyway I touched up the scorched spot with about 4 coats in total, and a few other spots that looked like the trace might've been slightly exposed just in case.

Fired it back up and no more fireworks. Cool. Still have the faint sympathetic signal though. Not sure where to start troubleshooting that.

thecr4ne wrote: Tue Jul 25, 2023 11:35 am I have a pignose G40V (similar in design to marshall 2204 I hear) that sounds pretty shrill to me. Like something's not there in the low-mid range, and the highs are murder. Tube swap didn't change this, Pots all do something, but I don't really know where to start to narrow down the cause. Any advice welcome. Schematic below.

mdc wrote: Wed Aug 23, 2023 5:25 pm It's an enforcer head, which is similar to the jammer, but has an EL34 power section instead of the 6L6 power section. $300CAD for the head and the empty cab, so I feel like I did pretty well - Garnets are getting PRICY in Canada.

It's an odd duck, one of Gar's later design AFAIK. There's an extra preamp/tube gain stage available via footswitch or a second input jack. The amp sounds a bit borked at the moment - the reverb doesn't work and I think there's some weird grounding nonsense happening. I assume it's the typical garnet spaghetti nightmare inside - I'll bring it by my amp-hobbyist-pal's house sooner than later and have him poke around.

It's missing the footswitch and also the front panel John Reis-style (which is just a plywood rectangle with some tolex on it and will take about 15min to replace). I imagine that also brought the $$$ down.

thecr4ne wrote: Thu Aug 24, 2023 10:47 am Update on the Pignose G40V

So the post-mod "ghost signal" may have just been speaker buzz? I really don't know, 'cause it just kinda vanished and didn't really coincide with anything significant. Anywho it's gone, and after the Power supply recap, shorting switchcraft input jack upgrade with 68K resistor removal of C9 and C21 and change to variable bias, it's good to go...except I broke half of the split shaft on the presence pot.

It's definitely not so harsh and ice-picky anymore, much meatier with nice usable crunch. I appreciate all the input from everyone.

TylerDeadPine wrote: Thu Aug 24, 2023 9:58 am Do you have an oscilloscope?

tallchris wrote: Sun Aug 27, 2023 10:48 pm Any recommendations for keeping a Quilter Bass Block from slowly vibrating off the cabinet besides “turn the fuck down” or “no really just turn down”? I guess I could just put it on the ground since it does just sorta look like a dorky little bowler hat on a 1x15.

I’ve also seen the 202 guitar head almost fall of a 4x12 so I know it’s just not me.