AC176 suitable for NPN Germanium circuits?

Frequently asked question on transistors: types, substitutions, how to test, use and misuse them.
User avatar
Seiche
Old Solderhand
Information
Posts: 2526
Joined: 01 Nov 2010, 00:16
Location: Germany
Has thanked: 231 times
Been thanked: 189 times

Post by Seiche »

IvIark wrote:I've got some P416A and GT108G as well. The P416As sound great in a Fuzz Face circuit but they're relatively low gain, they ranged from 40 to 70hFE and have zero leakage. They look very similar to the GT308B, same case design but painted grey instead of bare metal, but the GT308B's are probably a better choice because they seem to be slightly higher gain, going from 56 to 90 and again with zero leakage.

The GT108G's are cool. They're really small (smaller than a metal can silicon transistor) and were mostly in the higher Fuzz Face gain range, from 100 to 160hFE although a few measured much higher and were probably out of the useful range for us.

I've bought quite a few Russian transistors over the last few years and the only ones I've really been disappointed with are the NPN GT404B's. All the PNP ones have been good purchases.
hm that's kinda weird. The seller advertises his P416As as being in the Hfe-Range of 60-125 which would be pretty much perfect. Maybe a mistake? Or he measures them differently? And they don't seem to be painted grey, but bare metal instead. Same with the GT108B (60-130). Weird. Have you bought something from him IvIark?

It would be perfect if he had a higher gain version of the MP38A since I'm looking for NPN and I don't want to buy a 50-pack if the gain range is really that low and I can only use less than half of them. Is there something like a MP38B or MP38E?

User avatar
IvIark
Tube Twister
Information
Posts: 2235
Joined: 01 Jan 2008, 23:59
Location: Manchester UK
Has thanked: 562 times
Been thanked: 586 times
Contact:

Post by IvIark »

I've bought from a few sellers:

orpheus_2005
GT308V
P416A

gordelux04
GT402B
GT404B
GT322A
GT108G
GT320B

insa_electronics
GT313A

and have a few other types but I didn't note who I purchased them from. I know some people have bought GT308B from gordelux04 and were less than impressed by them, but some people who also bought from orpheus_2005 found them great and I've also been very pleased with mine. So there could always be differences in the P416A's from two different sellers based on those experiences, but my figures are accurate and the spread was based on a quantity of 50 from orpheus_2005.

GT402B's are good for Fuzz Faces, my batch ranged from 78 up to 193hFE with 38 out of 50 being 146hFE or under. But only 7 of them were under 100 and so a mixture of GT308B and GT402B would consistently give you the Q1 and Q2 ranges you'd be looking for.

I haven't seen any other suffix MP38# which could have suggested higher gain.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

User avatar
Seiche
Old Solderhand
Information
Posts: 2526
Joined: 01 Nov 2010, 00:16
Location: Germany
Has thanked: 231 times
Been thanked: 189 times

Post by Seiche »

yeah and everytime i google mp38 i just get firearms :D

Post Reply