MP38’s for sale

[Kroars]

Happen to stumble on this post from a seller I’ve bought from before, and thought I’d share. MP38’s x 10 for under $2. Shipping is $19 but you can get a few lots and make it worth your while. Just ordered 100 for under $40 including shipping.

Hope everyone is well.

10 Pcs MP38 (МП38, 2N94) USSR Germanium NPN Transistors | eBay

Transistors MP38 germanium alloy p-n-p universal low-frequency low-power. Designed to amplify small signals of low frequency, amplification, switching, pulse formation, application in ferrittransistor cells.

www.ebay.com

 

[thewintersoldier]

What is the gain range like on them?

 

[Big Monk]

If they were NPN I’d jump on them.

 

[manfesto]

If they were NPN I’d jump on them.

I think the Description is wrong, MP38 is NPN.

 

[Chuck D. Bones]

MП38 are definitely NPN. Every one I have bought has HFE under 80 (most around 60) and are quite leaky. Good for some circuits, not so good for others. With careful selection (pretty much req'd for all Ge builds) you can build a fine NPN Fuzz Face or Tone Bender MK1.

 

[Preverb]

So you buy a big lot and then sell the rest on ebay after picking through them? If you buy 100, how many would you expect to be good? I am not sure where I read this but I thought the Russian transistors tended to be more consistent in terms of leak / gain. But maybe that was specific to MP20s?

 

[Chuck D. Bones]

First of all, I would not resell my rejects, and if I thought a seller was doing that, I wouldn't buy from them. The MП38As I have bought were very consistent, particularly the last batch of "blue hats." Not a single reject.

Given that these are NOS parts, I would expect a few rejects and a fallout up to 10% is acceptable to me. The first batch of 100 2N1308s I bought on eBay had 8 dead ones. All of the rest were in-spec. The last batch of 100 (same seller) had zero rejects.

I can always find a use for any transistor that isn't dead. Some circuits require the transistor leakage to be within a certain range and some don't care. At the very least, a functional Ge transistor can be used as a clipping diode.

 

[Big Monk]

First of all, I would not resell my rejects, and if I thought a seller was doing that, I wouldn't buy from them.

This. 1000%.

 

[Kroars]

So you buy a big lot and then sell the rest on ebay after picking through them? If you buy 100, how many would you expect to be good? I am not sure where I read this but I thought the Russian transistors tended to be more consistent in terms of leak / gain. But maybe that was specific to MP20s?

That’d be a pretty shitty thing to do. I’ve had a lot of luck with Russian transistors in the past, so I purchase lots from reputable sources when I find them. Lastly, the PedalPCB forum is a an awesome community that like to help each other out with components when in need, always good to have extra on hand.

What is the gain range like on them?

Haven’t got them yet, but I’ll let you know when I do. I’d be happy to send you some when they arrive. Just send me a message in a couple weeks with your address and I’ll drop em in the mail.

 

[Preverb]

First of all, I would not resell my rejects, and if I thought a seller was doing that, I wouldn't buy from them. The MП38As I have bought were very consistent, particularly the last batch of "blue hats." Not a single reject.

Given that these are NOS parts, I would expect a few rejects and a fallout up to 10% is acceptable to me. The first batch of 100 2N1308s I bought on eBay had 8 dead ones. All of the rest were in-spec. The last batch of 100 (same seller) had zero rejects.

I can always find a use for any transistor that isn't dead. Some circuits require the transistor leakage to be within a certain range and some don't care. At the very least, a functional Ge transistor can be used as a clipping diode.

Oops, when you mentioned that they can be quite leaky, I assumed that it would require going through them all and picking out a few good ones. I was curious how many would be great out of 100. I plan to build a fuzz, Benson, and maybe some sort of Germanium boost at some point but that would be it for my germanium transistor requirement. So buying 100 of anything would be overkill

 

[Chuck D. Bones]

Sometimes leaky is good. With Germanium, it's a fact of life.

 

[Kroars]

What is the gain range like on them?

Just received them. Pretty quick shipping from Russia. Tested 10 an average of 50hfe/38uA.

 

[djmiyta]

What other pedals can be made with this transistor if there are others?

 

[Chuck D. Bones]

Just about anything that requires an NPN Germanium transistor is a candidate.

Fuzz Face
Skreddy Hybrid Fuzz
Skreddy Screw Driver
BJFe Pink Purple Fuzz
To name a few...

If the pedal is leakage-biased, like the Tone Bender Mk 2, then you will need something with higher leakage.

 

[mdc]

Tone Bender Hybrid / Marigold works well with low leakage Ge.