Russian GT308b - Rangemaster report

[Eirik]

So i received my gt308b's today. Ran home to measure them. My expectations were HUGE!

After measuring about 10 of them i started to feel disappointed... All of them measured ~ 50-55 hfe.
This downtrip just continued. Out of fifty trannies only one was in the "useable" range with 85 hfe. Allmost all the others were 50-60.
So I thought I at least had a lot of diodes to play with.

I built a Rangemaster using the 85 hfe trannie and it sounded really huge! Great, smooth and powerfull. A lot better then my oc140's IMO.
I did of course have to try some of the lower hfe's as well and they really surprised me! Changing the gain pot to a 20k made even the lowest gain trannies sound really great.
Not as good as the higher gain one, but still.

This is really confusing. Suddenly it seems to me the gain of the trannie in a rangemaster isn't all that important. Seem's like the different types are more different in character
then I've been willing to admit.  I know this is old news to a lot of you guys, but to me it was kind of a revelation.

Anyway, conclusion: The gt308b's are great sounding trannies. To bad most of mine were very low gain, but according to the data sheet I have, they are supposed to be hfe 80-200.
                              I guess my luck failed me this time.

[DDD]

GT308V have the highest gain among GT308 A-B-V (please note that Russian "B" should be pronounced like English "V").
So the high-gain GT308... is marked as " ГТ 308 В ". Medium-gain one is marked with " ГТ 308 Б ". Lower-gain is " ГТ 308 А ".

[Eirik]

GT308V have the highest gain among GT308 A-B-V (please note that Russian "B" should be pronounced like English "V").
So the high-gain GT308... is marked as " ГТ 308 В ". Medium-gain one is marked with " ГТ 308 Б ". Lower-gain is " ГТ 308 А ".

Yes I know. The ones I have are marked 308 B.

[Ivana]

Ну вот и славненько! 
Особенно порадовало "A lot better then my oc140's IMO"  Да и по утечке они дадут фору на порядок любому ОС44  ... А вообще-то что-то маловат получился Ку... При каком токе базы мерял?  Но, с другой стороны, 50-60 - тоже хорошее значение. При не самых слабых датчиках... Try the base divider not 470/68 but 680/100 kohm - maybe it helps 

[bluesdevil]

I also managed to get a batch of those with the same hfe (with leakage taken into account). Out of 40, most were between 50-65 hfe, But I got lucky and received 4 or 5 with hfe of 69-75, which is perfect for Q1 of Fuzzface and 2 devices with gains of 80-85 hfe for the Rangemaster. Not a bad deal, really.
      Before I got those, I bought a small batch of NPN Russian germanium transistors that measure really low.... like 12-20 hfe. Low leakage, but too weak for conventional circuits. Well, the good news is they worked out well for Q1 for a NPN version of Pete Moore's "Range Pig"!! I will give some sound samples and a full report later in a new thread.
      The Russian transistors seem to have very low leakage compared to other makes, just wish I could score some with gains high enough for the Fuzzface Q2 spot!!!!