Russian Germanium Transistors on Ebay

theblackman · Post by **theblackman** » 24 Jul 2007, 01:26

Hi, Does anyone here have any experiences with these transistors that you can buy off ebay?? I have no idea where to find the spec sheets or whatever are these going to be good enough for a couple rangemaster/tonebender/fuzz face clones?

Cheers,

soulsonic · Post by **soulsonic** » 24 Jul 2007, 01:33

I don't know about the GT-311, but I've made some really nice sounding Rangemasters with the GT-313. I expect the 311 is probably good too.
One odd thing to note: my Atlas tester tells me the 313 has a resistor shunt between Base and Emitter. This makes biasing a little different, but overall the performance is the same as far as I can tell. Just ignore any "stock" values for bias resistors and start from scratch on a breadboard to see what works good.

Post by **modman** » 24 Jul 2007, 02:45

haven't tried them yet, most have low hFE (40-50) some 70 and an ocassional lucky one with 95. Haven't tried them yet though

GT311J Box outside
GT311J Box label
GT311J box opened

Have to pick up that iron again. I'll have a look for the datasheet. I thought it was linked to at aron's one time...

theblackman · Post by **theblackman** » 24 Jul 2007, 02:50

those are exactly the ones i have except that they are GT311E which i suspect are even lower gain than the J ones

. Did you get a small russian datasheet with yours?

Are the low gain ones really useful for any diy boxes?

soulsonic · Post by **soulsonic** » 24 Jul 2007, 03:03

In the case of the 313 with the shunt resistor, most transistor checkers will give erroneous hFe ratings because of the resistor. My 313s all read in the 40 range, yet in reality they had plenty of gain for a booster circuit. I don't know if the 311 has the shunt as well, but if it does, that explains the low hFe readings.

Like I said earlier, just stick 'em in a breadboard and start tweaking, you should be able to use them in several different circuits with only minor changes if any.

theblackman · Post by **theblackman** » 24 Jul 2007, 03:10

you are probably right

https://cgi.ebay.com/Germanium-NPN-Tran ... dZViewItem

i think there are a lot of misprints/typos in this guy's listings though...

I think i'll just stick one in an NPN boost and get some measurements.

Kaos · Post by **Kaos** » 24 Jul 2007, 07:04

Has anyone of you got experience with the GT21AD?

I ask because i got 22 of them and I haven't found any datasheet yet

from what i measured i know that its a PNP device and it sounds good in a fuzz face

any suggestions of what to do with them?(except of building 11 fuzz faces

)

soulsonic · Post by **soulsonic** » 24 Jul 2007, 07:39

Everyone needs one of these:
http://www.peakelec.co.uk/acatalog/jz_dca55.html
Mine is like a gift from the gods.

theblackman · Post by **theblackman** » 24 Jul 2007, 07:40

probably any fuzz face derivatives... fuzz factory, skyripper fuzz etc.. or anything that uses a ac128

Kaos · Post by **Kaos** » 24 Jul 2007, 08:06

soulsonic wrote:Everyone needs one of these:
http://www.peakelec.co.uk/acatalog/jz_dca55.html
Mine is like a gift from the gods.

Does it measure the leakage current too?

Kaos · Post by **Kaos** » 24 Jul 2007, 08:25

theblackman wrote:probably any fuzz face derivatives... fuzz factory, skyripper fuzz etc.. or anything that uses a ac128

thx

skyripper fuzz looks interesting...

theblackman · Post by **theblackman** » 24 Jul 2007, 08:35

damn straight!

Post by **modman** » 24 Jul 2007, 14:51

theBlackman wrote:those are exactly the ones i have except that they are GT311E which i suspect are even lower gain than the J ones . Did you get a small russian datasheet with yours?

Are the low gain ones really useful for any diy boxes?

Damn, only now do I find the datasheet under the 'velvet coating', says
E types: hFE 20-80
J types: hFE 50-200
I types: hFE 100-300 (I is that the inverted N?)

Soulsonic wrote:Everyone needs one of these:
http://www.peakelec.co.uk/acatalog/jz_dca55.html
Mine is like a gift from the gods.

I have the earlier version!

I heard a good NPN Germanium should work in Gus' NPN Booster

Zj

soulsonic · Post by **soulsonic** » 24 Jul 2007, 19:09

Kaos wrote:
soulsonic wrote:Everyone needs one of these:
http://www.peakelec.co.uk/acatalog/jz_dca55.html
Mine is like a gift from the gods.
Does it measure the leakage current too?

Yes, it does. It's the best. It's so cool - you don't even have to know the pinout of the device your testing, just hook it up and it tells you the pinout as well as all the other necessary info.

lmkv15 · Post by **lmkv15** » 26 Jul 2007, 15:22

Good transistors for Fuzz and Booster are Russian MP20 and MP21 (Germanium PNP) the GT311 is Germanium NPN.
The groups:

MP20A and G: 50...150
MP20B 80...200
MP20 W, MP21G: 20...80
MP20D: 130...200
MP21W: 20...100
MP21D: 60...200
MP21E: 30..150

I use these transistors for Booster Clones. The leak current lies under 150 µ A mostly

regards Uwe

nokaster · Post by **nokaster** » 05 Nov 2007, 11:44

what are your opinions about the NPN germanium transistors AC187?
any good for use in a fuzz face and/or a rangemaster?

bajaman · Post by **bajaman** » 05 Nov 2007, 20:02

yes - try any germanium - just make sure you get the power supply polarity correct!!
cheers
bajaman

Post by **modman** » 06 Nov 2007, 08:33

Yes, my experience too: try the Ge to know. If it reads a hfe over 200 in your DMM is hardly worth trying it, but just a good reading won't tell you anything about the sound you will get.

good luck

trevize · Post by **trevize** » 06 Nov 2007, 08:56

I've built several bazz fuss with ac187. the hfe was probably over 250 and the sound was great. like having a germanium fuzz face but with awild sound and a slight octave effect.

sosodef · Post by **sosodef** » 07 Nov 2007, 08:43

what are some readily available easy to find high gain germs

I just went through about 30 trannies for one pedal. All of them were just not cutting it for this circuit.

Where can I find some newer, pretty stable, high gain germs?