Piggybacking trannies.

Do-it-yourself pedal building

Moderator: Ghost Hip

Forum rules
The DIY forum is for personal projects (things that are not for sale, not in production), info sharing, peer to peer assistance. No backdoor spamming (DIY posts that are actually advertisements for your business). No clones of in-production pedals. If you have concerns or questions, feel free to PM admin. Thanks so much!
Post Reply
User avatar
Bieling2
involved
involved
Posts: 52
Joined: Sat Feb 16, 2013 4:30 pm

Piggybacking trannies.

Post by Bieling2 »

Has anyone here tried this?

1. Take two identical random silicon transistors (for more mojo: your fav fuzz silicons)
2. Tie the BASES together,
3. Cut off one COLLECTOR
4. connect a 3k to 6k resistor between the EMITTER of the collectorless device and the EMITTER of the other transistor.


http://tagboardeffects.blogspot.com/201 ... anium.html

Does anyone have picture of how the resistor is connected between the two emitters of the transistors? Has anyone tried using a 10k pot between the two emitters and have pics of that, and how either method is then connected to the rest of the circuit?
User avatar
eatyourguitar
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 3127
Joined: Sun Oct 03, 2010 12:37 pm
Location: USA, RI

Re: Piggybacking trannies.

Post by eatyourguitar »

I made a graph that explains it.

http://i47.tinypic.com/x200at.gif

so piggy backing will decrease your gain (hfe).
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF
User avatar
Ben79
experienced
experienced
Posts: 510
Joined: Thu Nov 01, 2012 6:16 pm
Location: Germany
Contact:

Re: Piggybacking trannies.

Post by Ben79 »

Can this be done with germs too?
User avatar
eatyourguitar
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 3127
Joined: Sun Oct 03, 2010 12:37 pm
Location: USA, RI

Re: Piggybacking trannies.

Post by eatyourguitar »

in my opinion its pointless since high gain germanium is so hard to find. taking a germanium transistor Hfe 100 and dropping Hfe down to 50 does not have too many applications except maybe a range master.
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF
User avatar
Ben79
experienced
experienced
Posts: 510
Joined: Thu Nov 01, 2012 6:16 pm
Location: Germany
Contact:

Re: Piggybacking trannies.

Post by Ben79 »

Just wondered cos I've got a load of ac125s that are all over 200, some over 300. All test good for leakage on a DCA55. Was thinking of piggybacking them in a Supafuzz.

Is there a circuit that likes stupid hi gain germaniums?
User avatar
eatyourguitar
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 3127
Joined: Sun Oct 03, 2010 12:37 pm
Location: USA, RI

Re: Piggybacking trannies.

Post by eatyourguitar »

sell them to me! I will find a use for them. maybe a pnp muff? please don't waste them by dropping the gain down to 100 Hfe. I have recently noticed that the world is running short on good germanium transistors. the next generation of pedal builders might not have access to germaniums much at all.
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF
User avatar
Ben79
experienced
experienced
Posts: 510
Joined: Thu Nov 01, 2012 6:16 pm
Location: Germany
Contact:

Re: Piggybacking trannies.

Post by Ben79 »

A germanium muff sounds interesting but aren't the diodes doing most of the clipping in one of those? I like the effervescent high end on a muff but have always attributed it to the silicon inside. If it seems wrong though, even more reason to do it!
User avatar
rustywire
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 4715
Joined: Thu Dec 13, 2012 9:54 am
Location: on.

Re: Piggybacking trannies.

Post by rustywire »

Thread title misleading...
[B/S/T shoutouts] Shortlist: Hollow Earth|Ct5|856|Condor|Thermae|OP-1|half track reel2reel|Prophet6 ... :whoa:
rfurtkamp wrote:The only transparent thing I own is a set of drinking glasses.
Image
User avatar
Chankgeez
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 42176
Joined: Tue Oct 11, 2011 1:40 am
Location: https://www.youtube.com/watch?v=FGhbeHujNZQ youtube.com/watch?v=V-2l7kkBURc

Re: Piggybacking trannies.

Post by Chankgeez »

rustywire wrote:Thread title misleading...


:lol: Yeah, I expected behndy to be all up in here like nobody's business.
psychic vampire. wrote:The important take away from this thread: Taoism and Ring Modulators go together?
…...........................…
Sweet dealin's: here
"Now, of course, Strega is not a Minimoog… and I am not Sun Ra" - dude from MAKENOISE
#GreenRinger
User avatar
eatyourguitar
IAMILFFAMOUS
IAMILFFAMOUS
Posts: 3127
Joined: Sun Oct 03, 2010 12:37 pm
Location: USA, RI

Re: Piggybacking trannies.

Post by eatyourguitar »

Ben79 wrote:A germanium muff sounds interesting but aren't the diodes doing most of the clipping in one of those? I like the effervescent high end on a muff but have always attributed it to the silicon inside. If it seems wrong though, even more reason to do it!


high gains are part of the sound. you could use all germanium diodes for even more mojo. I really want to make a pnp muff with at least one MP16B in it. the gains on my MP16B are Hfe 100 max so I dont want to use 4 of them. they do however have a really bass heavy response so a MP16B in Q2 would be really cool mixed with other high gain PNP germaniums.
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF
Post Reply