The Amp Garage

I'd like a better way to organize and store my components: resistors, caps, switches, diodes, etc. I started by re-using a kit organizer, but I don't care for how most plastic organizers have non-ideal dimensions, and seem to require that you bend leads to make components fit. I have a decent amoun...

martin manning wrote: ↑Sat Nov 07, 2020 2:43 pm Put the divider on the screen node. That additional 1 mA will never be missed.

+1, have done exactly this on a couple builds, albeit with a 500K/100K divider. No problems whatsoever.

Very cool!
Is this the first project with the socket PCBs? What do you think of them?

Yeah pretty sure that recovery stage after the effects loop is wrong on the schematic.
Anyway the build is working now, here's a pic!


EDIT: Audio sample for the interested!

Hold up, is the DCCF coming out of the effects loop wrong on the schematic? Soldano_super_lead_60.pdf Is it possible to input to the cathode like this? I'm looking at other schematics, surely the 1K should be the cathode resistor on the first stage, 1M grid leak, and the 100K plate resistor on the f...

Thanks Aaron!

bal704 wrote: ↑Tue Nov 03, 2020 5:37 pm What is the value for the pot in the phase inverter?

Wondering that myself, and the taper?

+1 for seeing the schematic, I wanna see what the hype is all about.
Going out on a limb and guessing it probably some resistors and capacitors. Maybe a potentiometer or two.

the yba-1 i had called for way cooler bias than i would've liked on the factory schematic so that's very likely. i added 1 ohm resistors between pins 1 and 8 (one per pair would work in your case) obviously have to rewire what goes to ground but that and the tube bias calc on robinette's site make ...

I had one briefly, pretty Fender-ish.
Gain stage - fender TMB - gain stage.
DCCF driven effects loop, returns straight into long tail PI.
~460V on the plates.

If there was an actual PT fault such as shorted turns, the PT would be drawing very high current, and blow the fuse. That's what I was thinking too. I did fully fire it up, drawing about 1.4A at 118V, with ~5V on the screen dropper resistor. Side note, how does the biasing procedure work? It states...

I commonly see 7-15 watts drawn by unloaded PTs of various sizes. So your 0.8A draw is not outside the norm. Gotcha, it's a bit less, 0.66mA, but I hear you. Just to be 100% sure, I disconnected all the secondary taps, thinking maybe something wrong with the standby switch, or filament winding. No ...

Build looks great! Very clean

The tube filaments is a considerable current draw. Just the 4 EL34s present a 37 watt load on the PT. That would be .3A @120V in the primary even if the PT was perfect and had no losses. I'm not even gonna add in the other six tubes. So, the filaments of just the EL34s account for almost half of th...

Just picked up a ~74 Traynor YGL-3A. Album. Schematic. I've completed the work I wanted, mostly just replacing e.caps. I also modded the bias supply to be a bit safer (adjustment pot is now a variable resistor, rather than the bias being supplied from the wiper) I was forming up the new caps, and no...

sluckey wrote: ↑Wed Oct 14, 2020 9:12 pm A 10 turn pot would be more precise but I've never had any difficulty setting bias accurately with a 50K pot. I've used this pot on several builds...

http://sluckeyamps.com/6v6plexi/P-6V6_05_big.jpg

Alright cool, I'll give the 1 turn pot a try.