NPN Germanium transistor circuits?

[PBWilson1970]

I've been poking through my parts bins and turned up a bunch of NPN Germanium transistors looking for a project.

I've got some AC127 transistors (bought from Marc Ahlfs back in the day) and a single NTE101.

I'm interested in the Fuzz Aldrin (which fits, given the source of my transistors!) but wondered about other NPN circuits that use Germanium transistors that you would recommend. So many circuits are PNP and it's rare to find a good one it would seem.

Thanks in advance for the help!

 

[Big Monk]

I've been poking through my parts bins and turned up a bunch of NPN Germanium transistors looking for a project.

I've got some AC127 transistors (bought from Marc Ahlfs back in the day) and a single NTE101.

I'm interested in the Fuzz Aldrin (which fits, given the source of my transistors!) but wondered about other NPN circuits that use Germanium transistors that you would recommend. So many circuits are PNP and it's rare to find a good one it would seem.

Thanks in advance for the help!

Any PNP Fuzz can be converted into an NPN unit. Just make sure you flip any polarized components affected!

I've personally only built 2 PNP fuzzes EVER: An OC75 equipped MK II and a Joe Gagan Easy Face.

 

[PBWilson1970]

I had heard about the conversion but never tried it. Will it work with a 9v adapter? I dislike batteries no matter what Eric Johnson says.

 

[Big Monk]

I had heard about the conversion but never tried it. Will it work with a 9v adapter? I dislike batteries no matter what Eric Johnson says.

Absolutely. I have 3 NPN Germanium Fuzzes on my board right now sharing a supply with everything else.

Let's run through an example:



Here you would flip the following:

1.) Power (+ goes to Power Rail, - to ground)
2.) Power Supply Filter Cap
3.) Input Cap
4.) Emitter Cap

 

[peccary]

There is a simple mod you can do to turn the Gnat fuzz board in to an NPN Dizzy Tone. I've built a few and they sound like hellfire raining down upon you - in the best possible way.

You can read about it here: https://forum.pedalpcb.com/threads/pedalpcb-gnat-mod-the-dizzy-elk.7189/

 

[thesmokingman]

carbon black ...

 

[Big Monk]

There is a simple mod you can do to turn the Gnat fuzz board in to an NPN Dizzy Tone. I've built a few and they sound like hellfire raining down upon you - in the best possible way.

You can read about it here: https://forum.pedalpcb.com/threads/pedalpcb-gnat-mod-the-dizzy-elk.7189/

I think this is going on the 2022 list.

 

[PBWilson1970]

Fantastic fellas! I appreciate it. And so quickly too!

So... I can see a Fuzz Aldrin on my board, as well as that Buzzaround board I've had laying around waiting for transistors (after I flip the required parts) and maybe a few more. Nice!

 

[Username123]

Don't bash Eric Johnson man! He's got better tone than you will ever get! Oh that was a bit over the top. You could call me a big fan of Eric's. By the way, you might not be able to get the right tone without carbon zinc batteries. It gets you the vintage mojo!

 

[PBWilson1970]

Don't bash Eric Johnson man! He's got better tone than you will ever get! Oh that was a bit over the top. You could call me a big fan of Eric's. By the way, you might not be able to get the right tone without carbon zinc batteries. It gets you the vintage mojo!

Ha! I wonder if I'd ruffle some feathers with that jab. I'd wager that 99% of guitarists out there have better tone than I do!

 

[PBWilson1970]

carbon black ...

So a reasonably high hfe Ge transistor will work in place of a lower hfe Silicon? Interesting...

Good thing I ALWAYS socket my transistors.

 

[Bobbyd67]

You need 3 npn germaniums for a hoof reaper clone ^^

 

[Big Monk]

Don't bash Eric Johnson man! He's got better tone than you will ever get! Oh that was a bit over the top. You could call me a big fan of Eric's. By the way, you might not be able to get the right tone without carbon zinc batteries. It gets you the vintage mojo!

Eric Johnson falls into the category of players I respect for their skill and tone but that I do not particularly enjoy the music of. Very nice guy, great tone, but not a fan.

As for batteries, I've been playing around with them for some about a month or so. Not a huge fan. Now, it could be the fact that I have standard supply filtering in my fuzzes, which I have not rule out yet.

I think i'd rather pursue my battery simulator studies and build that rather than mucking about with batteries.

 

[Coda]

Hybrid Tonebender.

 

[caiofilipini]

Hybrid Tonebender.

This. I had a Hybrid MKII from Sola Sound for a bit, and it had an AC127 in Q1. Q2 and Q3 were silicon and had their markings sanded off, but a little research seemed to point at them being PN2222s.