Russian transistors in a Tonebender MK I

[MarkALeuchter]

My experience with Russian devices is limited; the ones I've used are incredibly consistent in terms of gain and very low in terms of leakage.  But can anybody suggest devices that are higher leakage in the 60-70Hfe or 85-100 Hfe ranges?

[JustinFun]

All the PNP Russian Germs I've tried have had zero or near zero leakage. You might have more luck with an NPN build though - MP37 or MP38. These tend to be leakier from my memory.

[patricks]

I think you might have to pay top dollar for transistors that meet all those specs, buy a big batch and test, or put a couple low-gain transistors together in a Darlington or Sizlacki pair.
I got five from DIY Guitar Pedals here in Aus, they're all low leakage (max 33 uA) but low-ish gain (one at 69hFE, the rest below 60). Rather than try buying another batch and testing or forking out for a known good one, I'm going to pair two up

[JustinFun]

All the PNP Russian Germs I've tried have had zero or near zero leakage. You might have more luck with an NPN build though - MP37 or MP38. These tend to be leakier from my memory.

Just went through a handful of Russian PNPs from my stash - nothing in the 100's leakage-wise and plenty at zero. MP16b seem to be fairly reliably around 60ua though (and around 75hfe).

[JustinFun]

Couldn't stop thinking about this and I love me a mk1, so I put together one with 3 GT404 russian npns.

Q1 75ua, 90hfe c8.8v b1.4v e1.4v
Q2 66ua, 83hfe c5.6v b0.2v e0v
Q3 91ua, 141hfe c7.8v b0.1v e0v

https://soundcloud.com/justin-chisnall-592485004/gt404-mki?si=f4f7e8156f0d4d68a74634bbbc09ce83&utm_source=clipboard&utm_medium=text&utm_campaign=social_sharing

Not perfect, but literally the only 3 GT404's I have so with a few to swap I'm sure you'd get there

[m_charles]

If newish at this, might be good to work backwards. Buy a tonebender set from a reputable place, socket the transistor slots, if the set you got sounds good, measure them, note the gain and leakage, then you have something to shoot for. I believe small bear has some premeasured sets.
I've built pretty complex large circuits and getting a tonebender to sound just right can be harder than those circuits.
The Russian transistors can def be "too good" in some cases.
Good luck.