D'Lite completed, but not working right - Please help!!!

[fharwath]

Well, I just finished my D'Lite build (followed Normster's layout and schematic exactly), but I'm running into a pretty serious problem. The clean channel works just fine, but the OD just won't behave. When on OD, if I turn the preamp volume up past about 9:00, the sound becomes very fizzy before just dying off. I'll play a note, and it will die immediately - after a few more seconds, no sound will come out of the amp at all (interestingly enough, that includes hum - I can have the master up, and no noise whatsoever will come through the speaker). What really gets me, though, is that if I turn the volume back down to 9:00 or lower, the problem doesn't go away - I have to actually switch back over to the clean channel and then switch back to OD for any sound to come out again. As long as I keep the volume below 9:00, the OD drive and level controls work perfectly, so I'm pretty sure the problem is solely on V2a; I'm thinking there might be a build-up of charge on the grid that's causing the tube to shut down. Anyway, I've attached some pics of the build. Any advice at all would be great!

[resophonic1]

Fharwath,

Do you have your 100k trim pot connected to ground and the 220k resistor under the circuit board? If not your missing those connections.

[fharwath]

resophonic1,

I did connect the 220k underneath the board, but I completely forgot to connect the ground I'll fix it and let you guys know how it works.

Thanks!

[novosibir]

... but I completely forgot to connect the ground

That's the cause of your problem! The OD1 tube had no chance, to bias itself through a grid resistance to ground, the previous coupling cap had no chance, to drain & recharge itself --> blocking distortion with following cut-off!

Larry

[fharwath]

Alright, I grounded the trim pot and fired it up and it was SMOKIN!!!

However, after about an hour of playing, I heard a "pop" (I was playing pretty loud, around 1:30 on the master) and suddenly there was this weird "gargle" whenever I would play a note - I'm thinking a cap blew...

Update: Yeah, it was the cap on the rectifier board (different value than called for, I had to change the bias circuit because the PT I used did not have a 45v tap) - I had it in backwards (see pictures). Whoops! Weird things happen when you're working at 2:00 AM

[Bob-I]

Congrats on the build. Looks nice and clean. Yes I've made the mistake of not grounding a trimmer before and had the same issue, glad you got it fixed.