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Most relays are DPDT, so you need 1.5 relays where you could use a single CD4053. I don't think dual gang pots will work because I've never seen a dual gang W20K. Also, honestly, I want to learn how to do this for future more complicated projects, and this is a fairly low stakes way to learn...

I was planning on using a CD4013 to actuate the logic, but what is the best way to use the same CD4013 to switch between the LED states? Ideally I want it to switch between to LEDS, a Green and a Yellow.

Hey folks, I have a question about using CMOS switching for potentiometers. (CD4053 in this case) I want to build a pedal that is a Tube Screamer and a SD-1. Both circuits will be on the same PCB, but I want each to be a "mode" with a push button (in this case because I like to build "studio"...

Any idea why the MOSFETS have such high source resistors in this design? Is it to do with the Vr biasing and clipping point?

Also, I found this design interesting... Mixing JFETs and MOSFETs. On the thread different circuits actually place the FETs and MOS in different locations in the circuit, though always a MOSFET into a JFET in a coupled "cathode" / source follower arrangement. Why might you choose MOSFETs in...

Do you have to measure the FETs IDSS and Vgs Off manually at the target voltage? I see the data sheets rarely specify much data after about 15v?

Is the bias resistor 1.5k at 9v specifically? I'm still trying to get my head around biasing FETs. I'm keen to design some circuits around the J113 as well as it seems much easier to bias and it cheap as dirt buy like 100 at a time.

Ha ha guess I'll have to do that on mine too.

I guess expensive is a relative / personal judgement. For me I'm always disappointed that the enclosure dwarves the cost of the rest of the circuit.

Damn, that is one expensive enclosure.

Have you ever done a whole preamp at high voltage, like a JCM800 or Rectifier type thing? I'm curious if there's benefits in running at higher voltage? It seems to me the initial work on these FET circuits was done at 9v just because that's the "pedal voltage", not necessarily because it was...

When using a JFET/MOSFET you mean?

*Renamed the thread as it is primarily about FET designs. Hey folks, so I've been reading Merlin Blencowe's Designing Guitar Preamp book. One thing that has interested me is the effect of essentially a poor design leading to some current leaking into the grid of the follower and therefore...

What is the context for this? What is the circuit? Both things you're referencing here are transistors, not voltage regulators as I understand the term. Something like an LM78x for instance.

Did you ever see this @Chuck D. Bones? An interesting way to lower the Vf whilst maintaining the softness. https://www.freestompboxes.org/viewtopic.php?t=32532&sid=9f44ed4305fd2974e985312204732e2c

Apparently STM32 can be programmed via Arduino IDE too. https://community.st.com/t5/stm32-mcus/how-to-program-and-debug-the-stm32-using-the-arduino-ide/ta-p/608514

Has anyone here used an STM32 as a microcontroller for switching? The reason I ask is that JLC has a few as a basic part for assembly. Just wondering how easy it is to program. I'm guessing you would need pins on the pcb in order to flash the firmware onto it. ESP32 boards are cheap on...

This topology is super interesting. http://milas.spb.ru/~kmg/jcm800fetLnd150_en.html

They're disappointingly simple from what I've seen.

Would be curious to see the schem too. I recently went down the LND150 rabbit hole. I'm quite keen to experiment with them some times soon.