Recent content by JohnnyCreepy

I’ve done some tweaking already. Instrument CH gain stages are 220K/2.4K, V2 220K/2.2K+bypass cap and 220K/1.5K+bypass cap. PI is concertina 62K/1.5K+62K. From my understanding this one was mainly marketed as a bass amp. It’s Dynacord Bass-King. I can relate modding is hard with this too as...

Well that might explain why the latter 2xEL34 PP output stage isn’t loud enough when using instrument/bass channel vol pots dimed. With enough drive from dirt pedals I need to turn back amps vol pots. So far coupling or bypass cap changes hasn’t helped with the lack of ”clean” output power...

One ch for stringed instruments and two for mics, keyboards etc.

I’m not fluent with SPICE and didn’t solve this earlier today, so could someone give some insight what’s going on this circled section? Treble bleed between 100+150K, lower freqs see 250K, but 50nf via 5.1K to gnd. 150K+50nF create lowpass, but how 5.1K affects here?

On Dynacord Bass-King I’ve been working on I made this sin you’re talking about, but the my bypass was done for a fuse on heater tap. 😌

Recently replaced vintage two dual e-cans with singles and trying my best still missed one GND plane connection. Had -VDC on places where it shouldn’t be, bias pots were non-responding, PI voltages totally wrong and terrible hum going on. One small jumper fixed it. Luckily nothing blew up...

I’d suggest dissolving egos and writing some uncanny vibed pedal building stories. Monk looked me winking his eye and using his tongue to moisten up his dry lips. He had not been able to admit his allergy to rosincore getting worse, affecting his health and being a great burden for his...

Same observations here with UL output induced superlead/bassman circuit. NFB is necessary when using dört pedals and playing loud.

Potential AI scam detected, as regular human spirits cannot keep their workspace drawers as neatly organized.

This might be related to your issue. I’d say you really need practice how to make your solder really flow. Most of the component connections on the PCB look like cold solder joints, but it’s fun to notice MORE pot has best joints. :unsure:

Nice catch!

Any update? :unsure:

For avoiding that solder transistors with long legs until circuit operation is verified. On that kind of long transistor legs there’s plenty to trim shorter. If you’re not using more expensive machined ones then YES and leg diameter/shape varies on transistors which causes contact looseness...

I suspect ”schematic error” by solder bridge or missing/intermediate gnd connection somewhere. Watch out for potential solder bridges between copper strips. Marked some of ’em. To exclude it being a problem run either an exacto knife couple times along area in between strips or do it with...

Nice to finally see a schematic showing how to use PNPs without a charge pump. I have some salvage AC12X/equivalent pnp transistors from old organ which will now find use.