madbeanpedals::forum

General => Open Discussion => Topic started by: jtn191 on March 28, 2015, 10:25:08 PM

Title: Germanium trans. specs (like max voltage)
Post by: jtn191 on March 28, 2015, 10:25:08 PM
It's weird, I tried finding data sheets but germ transistors are like the forgotten middle child of electronics. For a possible mic preamp project I was wondering what the max voltage these could handle:

MN16B, GT108B, some AC187

Also thought up what if these were Darlington pairs for more gain? Or in another scenario, what of you used fet's arranged as in Catalinbread's tube designs or Jack Orman's booster...don't think that's been done much.

Also I ran an sm57 into my Meathead or mkii Tonebender and into my console's hi z input...sounds better than I expected, in a lofi way.
Title: Re: Germanium trans. specs (like max voltage)
Post by: dont-tase-me-bro on March 28, 2015, 10:46:55 PM
I saw two of them in here.  whether or not this is accurate, I don't know

http://alltransistors.com
Title: Re: Germanium trans. specs (like max voltage)
Post by: davent on March 28, 2015, 11:06:36 PM
Built a rangemaster with with a ge Darlington pair based on the article at Small Bear.

http://diy.smallbearelec.com/HowTos/BreadboardGeDarlingtonRMs/BreadboardGeDarlingtonRMs.htm
dave
Title: Re: Germanium trans. specs (like max voltage)
Post by: jtn191 on March 28, 2015, 11:44:19 PM
Found this, which was helpful. Not knowing Russian was part of the problem http://www.diystompboxes.com/smfforum/index.php?action=printpage;topic=91699.0
Title: Re: Germanium trans. specs (like max voltage)
Post by: EBRAddict on March 28, 2015, 11:57:56 PM
You can also use 2 NPN Si and 1 PNP Ge to simulate a high-gain NPN Ge. Use 2 NPN Si in a low-gain piggyback to feed a PNP Ge in a Sziklai pair.

I just happen to be working on one at the moment.


The problem with Ge Darlington pairs is you are multiplying the leakage of Q1 times the gain of Q2.

Title: Re: Germanium trans. specs (like max voltage)
Post by: davent on March 29, 2015, 12:24:13 AM
With the Russian pnp ge's leakage is very very low.