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Transistor Recommendations wanted
- Thread starter jhaneyzz
- Start date
RetiredUnit1
Well-known member
szukalski
Well-known member
When I built mine, I found Q1/2 with low leakage and mid gain worked well. I used some Russian PNP, probably MP21A or MP42B, I don't recall as I favour the readings not the package. A lot of Russian stuff is 50-80 hFE and low leakage.. I got mine from Bulgaria via ebay here but the Ukrainian sources are also good and a bit cheaper if you don't have to pay EU customs duty.
Q3 needed more leakage, so I used a 2N1309 which was sourced from ebay as well.
Q3 needed more leakage, so I used a 2N1309 which was sourced from ebay as well.
andare
Well-known member
You already soldered the resistors and capacitors so it's too late 
If this is a Tone Bender MkIII the first two transistors are in a Darlington pair. Gain around 60 should do it. No particular leakage seems necessary here.
Q3 should be higher gain like 100+, I suppose a good amount of leakage like 200 should do it.
Refer to the build docs of this Aion project for the voltages https://aionfx.com/project/phobos-germanium-fuzz/
The last resistor cuts a lot of output. I have one on a pedalboard and it's still still too quiet even without it but my voltages are too low.
The tone section sucks a lot of volume.
Sounds great though.
My brief experience with vintage fuzzes has taught me that part number, gain, leakage and voltages are just starting points. Germaniums are unpredictable.
I don't like straying from the stock circuits but I do tweak the input and output caps and the value of the volume pot to brighten or darken a fuzz.
If this is a Tone Bender MkIII the first two transistors are in a Darlington pair. Gain around 60 should do it. No particular leakage seems necessary here.
Q3 should be higher gain like 100+, I suppose a good amount of leakage like 200 should do it.
Refer to the build docs of this Aion project for the voltages https://aionfx.com/project/phobos-germanium-fuzz/
The last resistor cuts a lot of output. I have one on a pedalboard and it's still still too quiet even without it but my voltages are too low.
The tone section sucks a lot of volume.
Sounds great though.
My brief experience with vintage fuzzes has taught me that part number, gain, leakage and voltages are just starting points. Germaniums are unpredictable.
I don't like straying from the stock circuits but I do tweak the input and output caps and the value of the volume pot to brighten or darken a fuzz.
jhaneyzz
Well-known member
If I could punch you, I would...
jhaneyzz
Well-known member
Nah. that's some kind of glue residue. All my other 100u electros were big 50v ones so I used this one. Tested it first and it's nearly dead on 100u.
going to hit it with some solvent but I ran out of steam last night.
jhaneyzz
Well-known member
So, it seems the RIGHT way to do this is to order a couple dozen (at least) from Ukraine and wait a month or two to get them, then test and hope a few are within the specs you need.
I'm ok if that's the answer.
In the meantime, is there a short cut to getting transistors that ARE in spec?
I'm ok if that's the answer.
In the meantime, is there a short cut to getting transistors that ARE in spec?
Harry Klippton
Well-known member
Small bear
benny_profane
Well-known member
Buying a matched set from somewhere (e.g., small bear).
A DMM with an hFE socket won’t be of much help for Ge transistors. Check out this for info on how to test gain/leakage.
Many of your questions have already been discussed at length. Search the forum—there’s a lot of great info here.
RetiredUnit1
Well-known member
I was going to use <drum roll/ cymbal crash> instead of ;-)
RetiredUnit1
Well-known member
I really don't know enough about transistors yet to make any recommendations, now if it was a tube or 400v capacitor you were looking for...
What really surprised me as I was studying how transistors work, I was really quite amazed to find they have the same function as a tube, but quite different means of accomplishing that task - materials instead of magnetic fields, and that both use negative polarity.
But then, the guys that invented them grew up studying tubes (or valves as some call them, because it's like opening and closing a valve that allows current to flow), so of course they would think in those terms.
What really surprised me as I was studying how transistors work, I was really quite amazed to find they have the same function as a tube, but quite different means of accomplishing that task - materials instead of magnetic fields, and that both use negative polarity.
But then, the guys that invented them grew up studying tubes (or valves as some call them, because it's like opening and closing a valve that allows current to flow), so of course they would think in those terms.
Synchrony Pedalworks
Well-known member
I just made a Tonebender clone using transistors from amplified parts. I used a Q1-2N404, Q2- 2N508 and Q3- 2N1307. I said f&$k ‘em (only because I was lazy) and selected them via sound, not HFe. Eventually, I was curious and measured the HFe being the following: Q1- 42, Q2- 103, Q3- 146.
Also, with Amplified Parts, you can find some of the HFe data on the website.
Certainly, use the HFe to guide you, but in the end, you just want to to sound great.
Also, with Amplified Parts, you can find some of the HFe data on the website.
Certainly, use the HFe to guide you, but in the end, you just want to to sound great.
jhaneyzz
Well-known member
I have a tendency to jump headfirst into stuff and buy a bunch of stuff without enough insight to make rational choices and end up with, well, my basement...
I've definitely found, with this hobby, to ask a few uber noob questions to at least get the lay of the land before ordering hundreds of dollars of parts.
And also, that 20 year old posts on older forums often don't age particularly well. Which, in and of itself, it a great reason to favor this forum over many of the older ones.
I don't mind being told to search the forums for answers to answers to questions that have been answered a million times, but it' suprising how much more efficient and accurate it is to just ask.
I spent a hell of a lot of hours and materials following 10 year old enclosure etching tutorials before finding a newer one with a vastly superior process from a member of this forum.
I've definitely found, with this hobby, to ask a few uber noob questions to at least get the lay of the land before ordering hundreds of dollars of parts.
And also, that 20 year old posts on older forums often don't age particularly well. Which, in and of itself, it a great reason to favor this forum over many of the older ones.
I don't mind being told to search the forums for answers to answers to questions that have been answered a million times, but it' suprising how much more efficient and accurate it is to just ask.
I spent a hell of a lot of hours and materials following 10 year old enclosure etching tutorials before finding a newer one with a vastly superior process from a member of this forum.
Ge transistors are an area where pedal manufacturers have used consumer ignorance to peddle huge amounts of crap about mojo regarding parts numbers. You will read how only the NKT275 will give you the ultimate tone for some pedal or other - it's generally all bollocks. Way back in the infancy of fuzz pedals the reason they used a particular transistor is because that's what was for sale at the time. They didn't test every type of transistor for ultimate fuzziness on the scale of fuzz. When they changed to a different transistor it's because that's what the shop had in stock at the time.
It's well known that no two Ge Fuzz Faces sound the same. (The internet told me that) If fuzzy sounds came out when the pedal was switched on that was good enough. The entire "haunting, vocal mids of the NKT275" is all modern day spin. Any beautiful, mesmerising sounds which happened were a happy accident.
I've tried a huge amount of brands and types of Ge transistors and some of the best sounding pedals I have built have been with Russian MP38s or MP20s or whatever. HFE has barely mattered. I do like an AC127 is a Skreddy pedal but have had equally good results with MP38s.
It's well known that no two Ge Fuzz Faces sound the same. (The internet told me that) If fuzzy sounds came out when the pedal was switched on that was good enough. The entire "haunting, vocal mids of the NKT275" is all modern day spin. Any beautiful, mesmerising sounds which happened were a happy accident.
I've tried a huge amount of brands and types of Ge transistors and some of the best sounding pedals I have built have been with Russian MP38s or MP20s or whatever. HFE has barely mattered. I do like an AC127 is a Skreddy pedal but have had equally good results with MP38s.
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