What is the Ge temp stabilizer diode mod?

[10acErnie]

What is the Ge temp stabilizer diode mod?
I saw it mentioned in another thread and I'd like to do this in my Fuzz Face.
Is there a schematic?

[MartyMart]

It's a reversed biased "Ge" diode just before Q1 to ground.
This can help stop "thermal runaway" when your pedal gets a bit hot.
Here's a schematic at fuzz central, just scroll down and read !

http://fuzzcentral.tripod.com/axisfacege.html

Marty.

[bioroids]

I did it a few years ago on my Easy face (Q1 Ge and Q2 Silicon): it worked great!

I never had to touch the biasing trimpot.

Luck

Miguel

[GFR]

http://www.geocities.com/gfr.geo/britface.html

[formerMember1]

yeah, i have been meaning to do that to my RM, but can't find a 1n34A ge diode in my area.  Is there any other Ge diodes i could use that will function as good as the 1n34a  is supposed to?

thanx 

[10acErnie]

Thanks everyone! I may get a chance to give this a try tonight.

formerMember1, where are you located?

[formerMember1]

formerMember1, where are you located?

i tried radio shack but no luck, they have other ones, but not 1n34a's.  I might be making an order to Aron for some, but that is all i need, and that would be alot of shipping for a couple diodes. 

[10acErnie]

formerMember1, where are you located?

i tried radio shack but no luck, they have other ones, but not 1n34a's.  I might be making an order to Aron for some, but that is all i need, and that would be alot of shipping for a couple diodes. 

formerMember1,

I thought I had some and I was going to send you a couple but I just realized I don't have any more!
I do have a few of the 1N4454 which, according to the mfg, replaces the 1N34A. Does anyone know if these will work for the Ge temp stabilizer diode mod?
formerMember1 send me a PM with your addy. If these will work I'll send you a couple.

[formerMember1]

yeah that would be cool, i would only need one diode.

First i gotta find out if that diode will work, It should, i don't see why it wouldn't.   

Is that your jimihendrix strat or a picture you got offline?

[10acErnie]

yeah that would be cool, i would only need one diode.

First i gotta find out if that diode will work, It should, i don't see why it wouldn't.   

Is that your jimihendrix strat or a picture you got offline?

I don't think the 1N4454 wiil work. I did a search and according to this thread the 1N4454 is a silicon diode.

http://www.diystompboxes.com/smfforum/index.php?topic=31551.0

I ordered some 1N314A's from Aron. I'll send you one when I get them if you don't have any by then.
Yup, that's my Jimi tribute Strat that I put together.

[formerMember1]

that's my Jimi tribute Strat that I put together.

THat guitar has one of the nicest aged finishes i have seen!  When you say you put it together did your build it?

thanks for the offer of sending me a diode, but i think i might be making an order to ARON very soon for some 3PDTs and other parts(1n34A)

**EDIT*** i just found a few 3PDTS in another box had, i'll send you a PM.

[birt]

why does the diode have to be Ge??

[formerMember1]

i think because the transistor we want to stop suffering from temperature is a germanium transistor.  i don't know if silicon would work or not?

[jmusser]

formerMember1, send me your home address, and I'll send you a couple in the mail in the morning.

[formerMember1]

formerMember1, send me your home address, and I'll send you a couple in the mail in the morning.

WOW you guys are really nice on the forum, i am glad that we all stick together and help each other here, unlike other forums on the net.

Thanks for the offer, but 10acErnie has got me covered,  i do appreciate it though, 

[aron]

AFAIK, here's the page on this and where I first saw it.

http://www.geocities.com/SunsetStrip/Studio/2987/britface.html#tempcomp

Thanks GFR!!!!!

Here's the home page:

http://www.geocities.com/SunsetStrip/Studio/2987/

[bioroids]

i think because the transistor we want to stop suffering from temperature is a germanium transistor.  i don't know if silicon would work or not?

It has to be Ge so the diode will drift with temperature the same as the transistor. I think other GE diodes should work the same as the 1n34.

Maybe the best would be using the base-emitter diode (reverse biased of course) of an identical Ge transistor. That way compensation would be perfect. Anyone tried this? Of course, you are wasting a good transistor he he.

May be important to mount the diode and the transistor as close as posible, so both are exposed to the same temperature.

Luck

Miguel

[formerMember1]

my transistor is a Black Glass Mullard OC44 in a Rangemaster.  It is built using the terminal strip, Could i solder the Ge diode directly to the tranny's legs or do i have to solder it to the terminals.  There is not much room, (if any) on the lugs of the terminal strip. 

Ok, We all know that Ge transistors sound different in different "room" temperatures, but what actually changes?  Because, my pedal will sound unbiased and bassy one day, and perfectly trebly and punchy sounding another day.  Is that a sign of a "temperature diode" needed in the circuit?


thank you

EDIT** i have the pedal biased at 7.00volts, and i noticed when it sounds "bad" the biasing changes to around 7.09 or higher.  And that is with a regulated power supply, not a battery. 

[bioroids]

Ok, We all know that Ge transistors sound different in different "room" temperatures, but what actually changes?  Because, my pedal will sound unbiased and bassy one day, and perfectly trebly and punchy sounding another day.  Is that a sign of a "temperature diode" needed in the circuit?

Quite posibly. Just be carefull to not damage that precious transistor when soldering the diode!

On the other hand, has anyone noticed, the Plate to Plate article Aron linked describes the principles of piggybacking using diodes??!! I thought that was not posible!

Miguel

[10acErnie]

that's my Jimi tribute Strat that I put together.

THat guitar has one of the nicest aged finishes i have seen!  When you say you put it together did your build it?

Thanks Man! I wish I could take credit for the Oly White finish but it's a Fender '57 RI body I bought on Ebay. It has a Warmoth neck and Texas Special pups. I finished the neck and put the guitar together.
Here's one I recently painted and reliced:
http://marykayestrat.com/