Is the internal resistor in these Russian germaniums skewing gain measurements?

[skiraly017]

I was thinking...the gain measurements people have been posting for the Russian germaniums seem to be lower than the range the datasheet states. If they have internal resistors, could that be throwing off the gain readings? The ones I've gotten sound very good to me and I haven't even measured them. Thanks.

[petemoore]

  Martin sent me some "R" PNP's.
  For a while I couldn't figure out the pinout, and the DMM was of no help there, I couldn't find any 'reasonable' Hfe numbers.
  I've got some in my FF so i can reference the pinouts of the others from there [memory..ughhh].
  Once I got them into circuits they worked great, 'contrary' to what the DMM didn't have to say about it.

[skiraly017]

The pinouts will throw you for a loop at first. I picked three GT308B's at random, dropped them in a Tone Bender clone and was very pleased with the results. No idea what the gains/leakages are.

[MartyMart]

I honestly don't know if that applies to the 308's , I'm the "martin" from pete's post BTW, but here's what I've
found FWIW.
308's that seem to measure between 40/80 hfe, using the proper method, drop into FF projects very successfully
so are perhaps in reality more like 70/140 !!
The higher hfe's that I've tried, measuring above 80 react more like they are 200 + ..ie TOO much gain and "mush"
Anyone else care to comment ?
I've seen them get a bit of a "bum rap" around here, but I'm a fan of them ....BIG time.
I use trimmers 99% of the time, so perhaps that's helping my bias tune ups a little.
Perhaps I just got lucky with my batch .... who knows !
MM.

[John Lyons]

Is ebay the best source for these? (GT308 GT309)

Thanks

John

[MartyMart]

Is ebay the best source for these? (GT308 GT309)

Thanks

John

Yes, here's the Ebay seller -  orpheus_2005  -  I've had a few batches from him with no problems.
Regards,
Marty.

[jakenold]

Just out of couriosity, which resistors do you replace with trimmers Martin?


Jake

[MartyMart]

Just out of couriosity, which resistors do you replace with trimmers Martin?

Jake

replace the 33k with a 50k trim and the 8k2 with a 10 or 20k trim, costs a dollar more but helps
the bias "tune up" heaps.
Or use pots, mark the value when it sounds good and replace with resistors for exact value
MM.

[joegagan]

hey john, did you get a chance to listen to or test the 2n2000s?

[mat]

I was thinking...the gain measurements people have been posting for the Russian germaniums seem to be lower than the range the datasheet states. If they have internal resistors, could that be throwing off the gain readings? The ones I've gotten sound very good to me and I haven't even measured them. Thanks.

Would also be nice to know if it affects the leakage reading too !

Matti T.