Great Jumpin Germaniums! (Ge Diode and Transistor Reviews & Discussion)

[Kinski]

Hey thanks. I already place my order with catodbg. I got D9E, D9D, D311, and 1D507A. 10 of each. That should be a good start to begin my GE diode collection.

Now I gotta start finding some projects for these things!

[Luke51411]

I haven't skimmed the entire thread, I read a few pages and didn't see anything so forgive me if I'm duplicating anything here. Has anyone tried GT313B trannies? I just picked up a DCA55 and now I want All the Germaniums!!!
From everyone's favorite Bulgarian seller I just a lot of 10 SFT323 which all had gains in the range of 150-200 but with .5-.9 ma of leakage. As usual it came with some bonus transistors which were SFT... I can't remember the number at the moment but they are black and mostly measured between 40-60 with very little leakage but I did get one that was around 90hfe with .16ma of leakage so this seems like a good candidate for a fuzz face or something.

[iggy]

Open question. I see our vendor from Bulgaria is selling some AC125T's Look like Telefunkins. Any one try them? Thinking about ordering some. The only ones I've tried are from Tungsram. And leaky as per usual.
Sound good. But nice to see something other than Tungsram for once.

anyone interested in splitting a bag?

[Luke51411]

funny, those are currently in my shopping cart

[iggy]

love to hear what you think of them, while they are still available.

I've had such missed results with Tungsram. And I and a bad GE monkey on my back. I think Rockett's fault. Gave me a couple Russian trannys, and I've been hooked ever since. cheeky bastard. Did I say that right guys?

[rocket88]

Woh, as emperor of the Ge Deathstar I warned all of you first, so I take no blame in your addiction. Lol

But seriously, I haven't tried those ac125's, but been looking at then while there up. A little expensive at $1 each, considering the price I pace for the tunsgram ones. Should be work a try. As far as the gt313's( I've read good things about them, and are the PNP versions of the GT311, which are supposed to be pretty good as well. They should be pretty low leakage as well.

I like the SFT323's, and have used them in circuits that like leaky transistors, like Q3 for tonebenders and their derivatives. Can be a little dark at times. The other SFT's may be SFT308's which I've used for the same types of circuits, but mine are between 60 to like 200hfe.

Again, fair warning be careful. You don't want to order everything and just have a ton of Germanium transistors if you don't really need them all. It just ends up being a waste of money if you do that, not to mention if you don't get the gains you're hoping for. Just keep that in mind young one.

Emperor out.

[motterpaul]

Just FYI, I have built this circuit, and I personally think it works best with NPN transistors. I did try it with AC125s and I personally was not impressed. As I recall others said the same.

I also built it with the NPN Germaniums and it sounded a lot better. I think I had MP38As

I built the version before the one with a "tone control" which I think just might be the first one here (except it is called "Green Giant". If you want to go with PNP (like the AC125s) you might have to build the version with the power inverter. I think Frank layed a circuit out for that.

I have built quite a few circuits with AC125s and I have found some amazingly good (IMO) layouts - Tone Benders, Rangemasters, etcs. To me, this just didn't seem to be one of them.

[rocket88]

motterpaul wrote

Just FYI, I have built this circuit, and I personally think it works best with NPN transistors. I did try it with AC125s and I personally was not impressed. As I recall others said the same.

I also built it with the NPN Germaniums and it sounded a lot better. I think I had MP38As

I built the version before the one with a "tone control" which I think just might be the first one here (except it is called "Green Giant". If you want to go with PNP (like the AC125s) you might have to build the version with the power inverter. I think Frank layed a circuit out for that.

I have built quite a few circuits with AC125s and I have found some amazingly good (IMO) layouts - Tone Benders, Rangemasters, etcs. To me, this just didn't seem to be one of them.

paul, we told you before that the AC125 is not a good transistor for the circuit, so of course it's not going to sound good, and that it would need tweaking to get it to work right. even silver tried it and made similar comments. you're experience with the PNP layout is with one type of PNP transistor, there are hundreds of different models. so you're experience is not even a drop in the bucket of trying the layout with PNP transistors. different transistors will yield different results. not only that, it is essentially a modified electra distortion, which WAS PNP to begin with. i have tried many different PNP transistors and it sounds great with the right ones, polarity does not dictate is the effect will sound good. it's been said to you before that you can not make generalized statements like that, especially when you have minimal experience with what you're commenting about.

not only that, you were told that the layout with the tone control was not finalized and had issues for instance output, yet you still built it and complain its not working right. please do not criticize a layout that is known to not work right.

side note, all but 2 layouts were done by me. the other two, one by Neil which is a modified one based on a schematic i designed, and the other by silver which is another PNP with inverter. so when commenting about a layout, give the right person credit.

it's things like that that really get under my skin, because others will read your comment and either made bad decisions with an effect, be turned off to something for the wrong reasons, etc.

emperors rant over.

[Luke51411]

The transistors marked as AC125 arrived and they didn't test well... I got about 10, the transistors that tested good were all below 10 HFE!!! They also showed up as NPN which I was under the impression that they were PNP. at least half of them showed up as diode network or low power thyristor on my DCA55 so I assume that means they are no good. I've sent a message to our Bulgarian friend and he's going to make it right.
I also bought a set of the PNP NPN GC511 and GC521 pairs it was listed as 6 but I think I received 10 pairs and a couple pairs of Tesla Trannies as well. The PNP in the pairs tested pretty high in gain 150-250 HFE with quite a bit of leakage .5-.75 ma. The NPN tested very low gain mostly around 15 hfe.
The lot of GT404A tested between 40-80HFE with leakage from .35-.6 ma on the DCA55.

[Luke51411]

Just to follow up on my previous post, I was just refunded for the suspect lot of ac125.

[Travis]

Luke did you get those Telefunken 125s? I forgot to post that I have some of those and didn't find them useful at all really. I think the hfe was super low

[Luke51411]

Yeah those are the ones. As stated, I've already been refunded. Great customer service! Maybe I'll throw them in somewhere a GE diode is called for... I didn't even ask for a refund just mentioned what I had found and was given a refund. I figured its good for him to know what he's selling especially if it doesn't line up with the listing.

[Travis]

Sorry I didn't warn you in time. Sounds like everything worked out alright anyways

The tungsram ac125 are good, I like the mullard/Philips ac125 best but those are harder to find and more expensive

[rocket88]

no only can you use them as Ge diodes, but you can also use them in Ge buffers. sometimes it's just the luck of the draw. i've got a few Ge transistors that measured weirdly, then tested them again and got a normal reading, and to be sure i waited and tested them again. but in any event, no Ge goes unwasted

[Luke51411]

Of course now ebay thinks I might be interested in Germanium Supplements... I suppose I could always ingest them and think of all the money I'm saving by not buying germanium supplements... Might be a bit pokey on the way down though

[iggy]

Luke,

 Thanks for posting you follow up on those trannys. I was just thinking about them. and now you've saved me the trouble and money. Plus I think they pulled them off Ebay. So that says a lot for the seller. found out they were poor quality and stopped selling them.

Unlike most sellers that just list them as untested.

Darn. I had high hopes for those. Maybe they'll show up on Miniflux's store.  

[bogey]

Hey everyone, hope you're all well.

I've not posted for a while, so here we go!!!!

A couple of months ago I scored some Ge trannies, they are:-

General Electric Company GET 104. PNP. hfe's between 32 and 78 with little(0.04ma) or zero leakage.

General Electric Company GET 106. PNP. hfe's between 44 and 94 zero leakage.

Newmarket NKT 272. PNP. hfe's between 58 and 77. Again little(0.04/0.06ma) or zero leakage.

So I'm wondering if anyone has had any experience using any of these or has anyone got any suggestions as to what I should try them in?

Any replies greatly appreciated,
Thanks Bogey.

P.S Could someone tell me what hfe values generally constitute low/med/high gain.

[Travis]

Most of those should work great for fuzz faces. Use sockets to find what sounds best to you

Try them out in a Rangemaster too.

Generally low hfe is like 0-50, med is something like 50-100, 100-130 is like med/high, and 130+ is high

[Beaker]

Agree with Travis. Good score Bogey.

Remember though, that not all Ge can be generalised. Russian Ge transistors usually measure lower than they sound (if you know what I mean) - if a build specifies 70-80 hfe, you can usually use something around 50 hfe, and get th same results.

[bogey]

Thanks Travis,

It's nice to know they should be useful, I only got the GET's because they had cute little red shrink sleeve jackets on and looked COOL!!!

Concise and informative as always.

Cheers,  Bogey.