Search results

Hmm so I've been testing the NPN versions the 3BX31C, and the TC1 doesn't detect the Iceo leakage on them, I'm not sure if that means the leakage is just very low, or if because it's NPN it doesn't think they are Germanium? Anyone got experience testing NPN Germs with a TC1?

Question for you. When might I want leakier transistors? Just took receipt of this haul and will test them before buying other Germs, but I guess might look into a small batch of GT402s. I'm mostly interested in preamp designs for both guitar, microphone, and live level. But everyone should...

Update, here's a re-test with the TC1. This actually seems useful? Having said that, they've just been sat at room temperature. Do they need to be used actively to stabilise?

This is the cheapest quality one I could find. https://nz.rs-online.com/web/p/rackmount-cases/8104264 No Tayda level stuff for rack enclosures it seems.

Thanks so much for this and going to all the effort of creating the sims. Will definitely tinker with some of this!

For what it's worth a Bc549C BS170

Yeah, I'll reserve full judgement on the capabilities of the transistor testing until I have more high quality Germaniums on hand.

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.