Recent content by jubal81

These are pretty interesting. I've been looking at options for driving a reverb tank and I haven't been able to setting on one yet. I don't like the headroom for most of these as most new stuff is designed for 5V-ish supply. I like the TI series of bridge tied amps like the LM4876. They're AB...

Leave off the LEDs. Connecting them correctly is too advanced for you at this step. All you need to figure this out is the continuity tester on your DMM. 1. Verify locations on PCB for connections, there are 4. 2. Rotate the switch and test to verify that.

The LED clippers are not in the original circuit. Their clipping threshold is very high so they are in the "no clipping" position and act more like protection diodes. If you want to be sure to get the connections correct, you can buy the 2P4T switch and get out your digital multimeter. Use the...

The dual LED is just that. It's two LEDs in one package. They're arranged in anti-parallel like typical clippers.

Bit of an old thread, but I've been thinking about designing a tester/matcher. I liked how Surfybear used LEDs for quick indications. One mode could simply be inserting 4 or more FETs at once, press a button and LEDs light on any FETs within matching tolerance. A more sophisticated approach for...

It's an input buffer. Most JFETs will swap in fine. Only common JFET I'd recommend avoiding for that position is J201/ mmbf201

I switched over to EasyEDA a couple years ago and I really like it. There wasn't too much of a learning curve coming from Eagle and it's got some features that make layout much easier, like when your cursor is over a pad it automatically highlights all the pads on the same net. Very handy! The...

Spotted something else on the 1176 schematic that could help a lot. To make the compressor JFET happy, we buffer and feedback half the drain signal to the source and the gate. There's another trick in the 1176 that helps tamp down distortion a lot. It's another feedback path (negative this...

That JFET buffering the source of the first one is still bugging me, especially how the buffer signal goes straight into that big cap to ground. I looked at the 1176 schematic and it feeds back half the drain signal to both the gate and the source, but there's a 10K resistor on the compressor...

I was looking at the Median schematic and I see a few changes that would make it perform a lot better and be easier to bias. Bonus: It would only take a couple more resistors and caps. There's no reason you'd need matched JFETs or have to select ones with the VP and IDSS Wampler used. The 5457...

Limit the current from the opamp through the diodes. Start with 1K - 10K and see how you like it. Also, the feedback resistor in the opamp loop should be at least 10X higher, considering the value of the gain pot.

Goodgoogamooga this is outrageous! I'm glad you pointed this out to me. Pure art. I mean, even polystyrene? Damnation.

Beautiful!! Really nice work and a great result for a first go at it! I'm working on a Mojotone Princeton and waiting for the custom cabinet. Hopefully not much longer. There were some mistakes in the Mojotone documentation and I wasn't thrilled with the quality of the small parts. Next time...

It's a long shot, but the cathode wire and output wire are touching, which could mean a bit of capacitive coupling.

A compact function generator would be pretty handy.