Ge Transistors

[FuzzMitch]

Can anyone identify (manufacturer etc) these spare Ge Transistors i was given for my 1970's Dunlop JH-2 FuzzFace?
The two that were in the FzFc are a NKT275, and a B175; so the two spares are what im wondering about and they both look the same tho different engraving on top, see hand written note in pics.
Thanks.

 

[FuzzMitch]

Yes it was modified w 3 extra dials, one im pretty sure being a bias dial. The two Ge's that were in it, when i bought it already modified 13yrs ago are a NKT275 and a B175 - original to this JH-2 or not i dont know. So i asked the the elect tech i bought it from could he get me two SIMILAR spare Ge's for future and he gave the 2 pictured (see original pics) plus some resistors; so now that ive unfortunately dropped it im wondering where the two spare Ge's are/from in case i now need to use them.
The movement in the BCE electrode is on the NKT275 (the B175 is ok); i can only assume the movement doesnt mean the BCE wires inside the can have come off because it was still working when i noticed this movement a year ago - so ild say its just come unstuck from the sealant where it enters the can, tho yes - not good. Inside Ge's can be more complicated than this pic but loosing the seal means oxidation starts over the bits inside over time.
Note: If these two spare Ge's need to go in im not able to do it, but ill post it to Ivan Richards near Gosford NSW, Australia, as one of Aust's leading amp techs.

 

[christinescoms]

To Dana: Thanks, i dont know what alpha or beta parameters is/are. Ill try to google.
To (Hulk): Thanks but by original Newmarket or the company Dunlop got to fake NKT's? I think it depends on when this NKT was made as theres no colour dots on it either, would you agree?
To SchmittTrigger: Thanks, when you mention 'those vintage trannies...' are you referring to the spares or the ones (NKT/B175) in the FzFce? Because its the two spares im wondering where/when they were made.
And what are 'BCE terminals'? - the three prongs/pins coming from each transistor?
A quick background: I bought the JH-2 FzFc 13 yrs ago, it was already modified with three extra dials by the bloke who gave me the spare Ge's - one dial im sure is a bias dial (an excellent dial for Ge FzFcs), BUT a month ago i dropped it so doesnt work (dont hassle me, im traumatised!) , but i think its the soldered wires not the Resitrs or Transtrs Fence Company. The values written on back plate are what he wrote for the Ge's that are in it ie NKT and B175.

I've got a small handful of RCA germanium pnp transistors with decent gain for fuzz faces. DCA 55 reports no leakage too, but they're very noisy in every circuit I've tried them in. I tried them in some broadcast builds and fuzz face circuits on the breadboard and they were unusable. I haven't tried using them as diodes yet. Is there anything else I could try?

 

[augustinetez]

If your getting a no leakage message I think something "may" be wrong - leakage is part of a germaniun's make-up, there is always some.

100% sure you have them connected correctly re E B C ?

Other thing to check is the biasing, they only need 0.3V or so compared to silicon transistors 0.6V.

 

[ZipZapOuch]

If your getting a no leakage message I think something "may" be wrong - leakage is part of a germaniun's make-up, there is always some.

100% sure you have them connected correctly re E B C ?

Other thing to check is the biasing, they only need 0.3V or so compared to silicon transistors 0.6V.

The gain tester on some modern meters don't work well with germanium transistors.

 

[FuzzMitch]

Ahh, yes ive heard that about modern meters too.
But someone here will lead you on the right testing path im sure, im a 'user' not a 'builder' of Fine Guitar Gizmos (Pedals). FuzzMitch

 

[danadak]

Good ref manual for Germaniums :

GE_-_Transistor_Manual_1964 : Free Download, Borrow, and Streaming : Internet Archive

archive.org

Regards, Dana.

 

[FuzzMitch]

Good ref manual for Germaniums :

GE_-_Transistor_Manual_1964 : Free Download, Borrow, and Streaming : Internet Archive

archive.org

Regards, Dana.

Gen.Elect.1964 !! I'll print that off and keep it for refrnce. Thanks for that.
I find it intriguing the dynamics surrounding transistors Ge's and like, altho i cant understand most of it.

 

[ZipZapOuch]

Gen.Elect.1964 !! I'll print that off and keep it for refrnce. Thanks for that.
I find it intriguing the dynamics surrounding transistors Ge's and like, altho i cant understand most of it.

Summary, germanium were the first commercial transistors (before silicon) and some/most/all would be noisy/static/fuzz and some distorted the audio. Eventually, everyone except the guitar distortion box manufacturers wanted silicon-based transistors to accurately reproduce/amplify/switch and most anything else that you'd want to do with a transistor. The guitar pedal guys wanted distortion - so they long for the days of Ge transistors and try to buy any available. Unfortunately, transistors made on those days, degrade over time and leak more, fuzz more and suffer from other rust/oxidation/dopant diffusion issues.

Fortunately and unfortunately, digital signal processors can do much of the same thing that Ge distortion pedals could do but a bunch of artists don't like the digital elements - until they record and upload their songs to a streaming service (Ha ha!). Analog streaming services are a difficult bunch to work with.

 

[FuzzMitch]

I've got a small handful of RCA germanium pnp transistors with decent gain for fuzz faces. DCA 55 reports no leakage too, but they're very noisy in every circuit I've tried them in. I tried them in some broadcast builds and fuzz face circuits on the breadboard and they were unusable. I haven't tried using them as diodes yet. Is there anything else I could try?

Yes check your testing setup as Augustinetez mentioned, you may have some beauties there.

 

[FuzzMitch]

OK MY FUZZFACE IS BACK IN ACTION!!
It was a broken solder joint and the wire came off when i took the input jack out. As i lifted the jack out it came off the other end leaving a full 5cm long wire off. A friend checked (multimeter) where the wire had come from, soldered, and bingo -back in action. The slipping electrode still doesnt seem to be a problem as was the case before i dropped the FzFc, but as i mentioned it could lead to oxidation inside the Ge's canister.
So thanks everyone for your 'input'.
What i ( and friend) might do, since my searching revealed cheap FzFc kits for sale, is build another FuzzFace with the spare Ge's and Resistors i was given and see what they sound like.
So thanks again everyone, very much enjoyed your advice.

 

[ZipZapOuch]

OK MY FUZZFACE IS BACK IN ACTION!!
It was a broken solder joint and the wire came off when i took the input jack out. As i lifted the jack out it came off the other end leaving a full 5cm long wire off. A friend checked (multimeter) where the wire had come from, soldered, and bingo -back in action. The slipping electrode still doesnt seem to be a problem as was the case before i dropped the FzFc, but as i mentioned it could lead to oxidation inside the Ge's canister.
So thanks everyone for your 'input'.
What i ( and friend) might do, since my searching revealed cheap FzFc kits for sale, is build another FuzzFace with the spare Ge's and Resistors i was given and see what they sound like.
So thanks again everyone, very much enjoyed your advice.

I would be really tempted to get one of these as a staring point and, if you don't like the way it sounds, at least you have the enclosure with graphics, connectors, stomp switch, pots and battery connector for $20 including delivery.

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[FuzzMitch]

Yes thats cheap for that good D2 Fuzz pedal. Altho ild add a bias control (for variable control) seeing as the spare transstrs i have are Ge so that enclosure is too small.
And D2 uses Si transtrs which dont produce the harmonic headroom the Ge's do with mine, which is a pet luv for me (IMO).
But that is a good Fuzz no doubt about it.
I have an original FenderBlender using Si's which is a wild sounding pedal (see pic); Fender went with Si's first in 1970's then as Ge's were re-fashionable went to Ge's then back to Si's in the 1990's. I bought mine from a Pawnbroker in 2005 for $180 now worth on Reverb $900-$1,200.

 

[rjenkinsgb]

The slipping electrode still doesnt seem to be a problem as was the case before i dropped the FzFc, but as i mentioned it could lead to oxidation inside the Ge's canister.

I'd be tempted to put a bit of superglue or epoxy on the transistor underside to seal the wire; both to prevent movement (which could break the internal connection) and make it airtight.

 

[FuzzMitch]

Yes im very tempted to do just that, tho im loathe to move it or desolder to access but i think i can get some superglue on a toothpick. Yes that is seriously on my mind, thanks rjenkinsgb.
Im still getting over that its working after just a bloody wire came off; and i live in a unit and have to go somewhere to play it.

 

[Pommie]

Guess it's an age thing but I can't hear any difference. Maybe I never heard distortion as it should be.

Mike.

 

[ZipZapOuch]

Guess it's an age thing but I can't hear any difference. Maybe I never heard distortion as it should be.

Mike.

The weak signal from the guitar's "pick-ups" goes to the "stomp box" first. Some pickups are not as "hot" as others, that is, produce a smaller voltage than others. The small output voltage 0.5 to 1V into a 1M load - means you don't have much headspace to turn on the transistors and Ge seems to work better.

 

[audioguru]

Guess it's an age thing but I can't hear any difference. Maybe I never heard distortion as it should be.

Mike.

Yes, we lose the high frequencies of our hearing (harmonics and distortion) early. I got hearing aids at age 69 and they are adjusted to match my hearing loss every year. Now I am age 78 and the hearing aids boost 1kHz a little and boost higher frequencies almost double (+30dB at 10kHz) as much as a treble tone control set to maximum.

Maybe all electric guitar players have enough hearing loss so that they cannot hear the extreme distortion they produce.
Here are graphs of normal hearing loss with age:

 

[ZipZapOuch]

Maybe all electric guitar players have enough hearing loss so that they cannot hear the extreme distortion they produce.

The guitar players DO notice the distortion - electric guitar players WANT the distortion. The distortion so they can make their own unique sound. Some early rockers, like .chuck Berry ( older than you) used to poke holes in the speaker of his amplifier with a screwdriver to make it sound oddly. Getting the crunch of heavy metal bands or lilting tones of some psychodelic bands is just not possible without distortion pedals (also known as "effects" pedals or, simply, "stomp boxes"). It's all about the memorable and unique sounds.

 

[FuzzMitch]

Guess it's an age thing but I can't hear any difference. Maybe I never heard distortion as it should be.

Mike.

Just experience and what you grew up with ie fuzz wasnt around much after the '70's/80's distortion boom.
Music is an age thing - the sounds in your head, in that the '80's born will have different musical preferences than '60's plus their parents music will have an influence. And i dislike (hate) '80's music and later - ok 90% of it..
I have a distinct luv/guitar influence for '60's psychedelia/heavy rock but ill never be torn away from clear, clean jazz and classical, even 'big band' music, from my parents.
Psychologically 'formative' years are distinct,

 

[audioguru]

I like to hear the musical instrument live or hifi and the way the musician plays it, not "effects".