Search results

I think the issue is actually oxidation, which is caused by moisture, but can't be reversed by removing the moisture.

What's the TlDr, did dehydrating actually improve the specs at all? Seriously though, has anyone ever tried coupling Ge transistors to a heatsink similar to a MOSFET?

TLDR: AVOID. Hey folks, so given that I'm sure these FNIRSI devices have popped up on people's radars I thought I would share my experience with the DSO-TC4, a combination signal generator, oscilloscope, transistor tester. I purchased this device primarily for the SigGen and Oscope abilities...

I think there is a certain application where this is a desirable outcome, not in the "amp simulator" aspect perhaps, but I'm thinking as part of a boost circuit you may want a bit of extra compression without too much harmonic content.

Definitely interested in the home brewed stuff. I'm more interested in the "compression" effect of the cathode follower. With or without bootstrapping. I've been playing my Victory Cooper preamp over the weekend, and IMO the vox circuit does that compression thing really nicely, even when clean.

Almost any BAT diode will do the job. The BAT56 is a bit lower than the other common ones.

Going back to the original cathode follower concept, do you have any starting point schematics I could look at? Either at 18 or 24v? Would going LND150 into a JFET be a good idea if it's all about current flowing into the "grid"? Or maybe the other way round?

I would bet it's more likely they are polishing old germs in order to facilitate the relabeling process.

This specifically. https://www.ebay.com.au/itm/197094365139 As long as many of them fall within the range specified I'll be happy. Might even sell some left overs if they test well enough. We'll see.

I do need to try the RG keen method too. I don't know how much I trust the TC4. Really useful as a sig gen / oscope but probably not as reliable for transistors.

I wonder if the Chinese germanium bubble has already burst? Seems no one recently has tested any of worth. I might try them as diodes. I'm not really a big fuzz guy. More preamp type circuits. Maybe some Darlington pairs could work? But even then I think the leakage is too high? I bought a box...

Might as well share my experience here. I've never built anything Germanium, and I'm not sure I fully trust the DSO-TC4, but I ordered 10 each of 3AX31C and 3BX31C, just to see what sort of parameter spread you might get. Not sure if any of them will be useful for a circuit?

I like building my own too, the desk mounted stuff is especially nice.

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.