Russian npn germanium transistors GT311

[MartyMart]

I have not tried those in RM's so I didn't notice any "hiss" going on.
I used a pair of 402's ( one a and one b suffix ) in a "RockFace" which sounds like a real
expensive "BOOTEEK" overdrive/Fuzz and has become a real friend to my rig !
Sound file of the culprit :
http://aronnelson.com/userfiles/RockFaceFuzz.mp3

309's - I've dropped into several PNP fuzzes and got nice results, mine always have trimpots
though, seems pointless to try to find some that "just work" with that resistor value !

MM,.

[DDD]

There was a funny warning in the old Soviet articles for the DIYers, something like this: "Be extremely careful while soldering {Ge} transistors, always use a good heathink attached to the pins, don't bend the terminals closer than 3-5 millimetres to the case, and protect them from the electrostatic voltage. In the opposite case the transistors may be damaged completely or may lose some of their characteristics. Also, the high-frequency transistors {just like GT311} can cause RF oscillating even in the low-frequency circuits resulting in the EXCESSIVE HISS and even critical overheating of the p-n junctions".
I do not believe that FF or the similar circuits are able to self-oscillate, but who knows? ;-)

[dano12]

Hey Meanderthal, thanks much for the lead. I ordered a few boxes of Stalin's finest and they arrived today. I've been looking for an interesting transistor to use in an Electro-based distortion and the Soviet KT312's are just about perfect for a great light overdrive. I'll post pics of the completed box when its done. In the meantime:

[Meanderthal]

 Glad to be of help...

Ain't they cool lookin' though? I also got a kick outta the funky box that almost says transistor... didn't yours come with the weird cardboard insert? Or ya just dumped em out?

[vanessa]

There was a funny warning in the old Soviet articles for the DIYers, something like this: "Be extremely careful while soldering {Ge} transistors, always use a good heathink attached to the pins, don't bend the terminals closer than 3-5 millimetres to the case, and protect them from the electrostatic voltage. In the opposite case the transistors may be damaged completely or may lose some of their characteristics. Also, the high-frequency transistors {just like GT311} can cause RF oscillating even in the low-frequency circuits resulting in the EXCESSIVE HISS and even critical overheating of the p-n junctions".
I do not believe that FF or the similar circuits are able to self-oscillate, but who knows? ;-)

I wonder if there's some truth to that. The pins are pretty rigid compared to other transistors. On the few builds I've swapped them in (via socket) one of them was a fuzz face that when I put the transistors into my enclosure I found that the metal tops of the transistors grounded something out on one of the pots. In order to remedy this I had to bend the transistor down. After that the other pedals I swapped these into I did that trick from the get-go. I found no hiss with the fuzz face but the rangemaster, and a tonebender did have a little in the background. Also the fuzz face had just a hint of crackle like an old 45. I don't think I bend them anymore!

[MartyMart]

I just cut the leads down to around 7mm and use sockets, the round "milled" type
are a good tight fit, due to the leads being quite thick .... they dont budge at all !!!
I have a "RockFace" that uses 402's and it's superb and VERY quiet too.

MM.

[brefmint]

So what the heck do you guys do with the 4th leg? I'm a noob about to start building Fuzz Face circuits. I was planning on using a socket but they have 3 holes. These transistors look to be a great deal but I don't won't to order them if I don't know what to do with the 4th leg.

Thanks!

Matt

[Meanderthal]

 The 4th leg goes to ground. It's attached to the metal case of the trannys, adds extra shielding I guess. They work without attaching it, but... they ARE quieter when that leg goes to ground.

[brefmint]

Thanks. So I would just run a jumper wire from the leg to the ground?
Which of these would sound better in a Fuzz Face--- ГТ311Ж(GT311J) or ГТ311И(GT311E)

Thanks for your help!
Matt

[mac]

There was a funny warning in the old Soviet articles for the DIYers, something like this: "Be extremely careful while soldering {Ge} transistors, always use a good heathink attached to the pins, don't bend the terminals closer than 3-5 millimetres to the case, and protect them from the electrostatic voltage. In the opposite case the transistors may be damaged completely or may lose some of their characteristics. Also, the high-frequency transistors {just like GT311} can cause RF oscillating even in the low-frequency circuits resulting in the EXCESSIVE HISS and even critical overheating of the p-n junctions".
I do not believe that FF or the similar circuits are able to self-oscillate, but who knows? ;-)

Boiroids game me some russians Ge transistors recently. THANKS Miguel!

I measured them, some were really low leakage and high hfe. I breadboard a FF and tried some. I handled them as I usually do with my rock-solid Toshibas and Matsushitas. I could not bias them. I used a jap and the circuit sounded perfect. Put the russians again and nothing. So I re-tested them just to find that hfe & leakage had changed a lot. I diode-measured the E-C and I got 1000 to 1200 with my DDM on both directions, should read 1. I think that I "fried" some of them with my hands.

mac

[Meanderthal]

 Well, the ones I got were the ГТ311И, which are supposed to be highest gain, and they all tested between 45 and 110 hfe(without taking leakage in account), so I wouldn't go any lower gain than that! Hard to imagine what the 'low gain' ones are like!

Also, with these, even though ya get a pile of them, it wasn't easy to find good pairs in a standard Dallas circuit(as opposed to 2N404a, which seem to enjoy jumping into FF sockets- super easy to find good sounding pairs), so I would strongly recommend a bias trimpot! They're weird... which leads me to-

The 4th leg. Yes, jumper it to ground. PITA, ain't it? But, there is a certain logic to shielding the tranny itself...

[brefmint]

Thanks for all of your input John. NPN Germs are pretty hard to find these days. Especially this many for such a small price. It's nice to know more about these.
Matt

[theblackman]

I just grabbed myself 100 GT311E transistors, I am not sure what the E stands for and I can't find any info on the net, are these going to be high enough gain for you standard tonebenders and fuzz faces??

Cheers, Rich

[MetalGod]

I just grabbed myself 100 GT311E transistors, I am not sure what the E stands for and I can't find any info on the net, are these going to be high enough gain for you standard tonebenders and fuzz faces??

Cheers, Rich

I think someone earlier in this thread mentioned that the 'E' suffix is the lowest gain version of this transistor.  I've got 100 of these too, speaking of which...

I've put one in a RM circuit and can't get them to bias...

Vs=8.56v
B=0.790v
E=0.869v
C=8.53v

Any ideas?

[soulsonic]

What are the values of the resistors you have in the circuit? You should be able to get it to bias if you fool with them a little.
I usually use 82K from Base to Ground, 470K from Base to V, and 2K for the Emitter. That usually gets me in a good ballpark to start with.

[Dragonfly]

What are the values of the resistors you have in the circuit? You should be able to get it to bias if you fool with them a little.
I usually use 82K from Base to Ground, 470K from Base to V, and 2K for the Emitter. That usually gets me in a good ballpark to start with.

Try using a 100k trim pot in place of the 68k resistor to ground in a normal RM. Should be easy to bias then.

[petemoore]

  I've recently recieved a bag of Russian tranny's.
  They look like little land mines, the center leg is fastened between the others to the can.
  I can't figure the pinout, the meter just makes a wierd beeping sound when the legs are pushed in a couple different ways, I tried a few, got beeps but no reasonable readings...couldn't determine pinout, and have given up for the moment.
 

[bluesdevil]

I also received a box of those NPN GT311E russian germs recently. Only tried 1 in Gus' NPN Booster circuit and it worked without any problems. Need to try them in other circuits, but I fear the gain is so low on mine they'll sound crap anyway. I'm getting a 15 to 25 hfe reading without even taking leakage into account.... I'm amazed it worked in that booster! Man, that data sheet is wrong about the gains, holy shat!!!
If any of the experienced U.S. builders here want a few to experiment with, drop me a message.
   Pete: With the ground leg facing you, the pinout should be BCE, if you have the same ones.

[theblackman]

i believe these transistors have a shunt resistor in them that's why you read such low gains.

[MetalGod]

I also received a box of those NPN GT311E russian germs recently.  With the ground leg facing you, the pinout should be BCE, if you have the same ones.

is that BCE with the ground leg facing you and looking from the top of the transistor or the bottom?