This Week on the Breadboard: Germ Warfare

[darwin999]

Chuck's Germanium FETish
Germ FETish
etc

 

[jwin615]

Germanium Scheiße Party
It's dirtier than a glass top table!

 

[HamishR]

Dirty Germs
Germane Dirt

 

[jwin615]

Germadoodle

 

[Chuck D. Bones]

Germanium Shepherd

 

[szukalski]

It'll interesting to verify this one, it was tricky with my (self-induced) layout constraints.

 

[Chuck D. Bones]

HamishR is not going to like that crooked board layout.

 

[Chuck D. Bones]

Final Version.
Changes: R2, R10, R14, R20-R22, C3, Q3, bias network.
MOSFET & JFET sound the same, MOSFETs are more consistent (Vth varies less than Vp).

 

[Cybercow]

Ger Burgers

 

[music6000]

Final Version.
Changes: R2, R10, R14, R20-R22, C3, Q3, bias network.
MOSFET & JFET sound the same, MOSFETs are more consistent (Vth varies less than Vp).

View attachment 121923

 

[jwin615]

Let us germ

 

[Chuck D. Bones]

To paraphrase Bob Marley: "And I hope you like Germin' too."

 

[jwin615]

Almost Polish Drive

 

[bluedmc777]

I like “Germanium Hammer”.

 

[HamishR]

"Um - Germany?"

 

[zakco]

This looks really interesting!
I have a bunch of low leakage MP38As on hand. Is there an optimal hfe range for the different transistor stages?

 

[Chuck D. Bones]

Maybe, but I don't know what it is . My recommendation is try whatcha got, get into the ballpark of the voltages noted on the schematic and see how it sounds. I tried a few different transistors and they all worked fine. My AC127s are leaky (most are) so the only good place for one of those is Q4.

 

[Chuck D. Bones]

Germanium - Über Alles!

 

[pcbcool]

Nice work! The changes to the biasing, tone network, and gain control sound really well thought out. I especially like the idea of using the JFET source follower to avoid loading the tone network. It looks like a fun circuit to experiment with on the breadboard.