Germanium Transistor Orientation

[Superjab71]

Hi, I am building my first pedal, the Fuzz Foundry, and I bought these two Germanium transistors (GT308V and P416V) from GuitarPCB. Are the diagrams for the board wiring they attached accurate for the PedalPCB boards? May be a stupid question but I don’t want to take the chance of damaging these.

 

[EGRENIER]

Hi, I am building my first pedal, the Fuzz Foundry, and I bought these two Germanium transistors (GT308V and P416V) from GuitarPCB. Are the diagrams for the board wiring they attached accurate for the PedalPCB boards? May be a stupid question but I don’t want to take the chance of damaging these.

Your fuzz factory board silkscreen will have the BCE holes identified. Just match the legs to the right hole. If you need to cross the legs, use some shrink wrap to avoid shorts.

 

[szukalski]

Also. Socket those bad boys. Future you will potentially say thanks.

 

[swelchy]

Also if you dont have a cheap transistor tester now is the time to get one.. it will help you identify the pinout of your transistors as well as give you an idea what their gain is

 

[EGRENIER]

Also if you dont have a cheap transistor tester now is the time to get one.. it will help you identify the pinout of your transistors as well as give you an idea what their gain is

Any suggestion on that… I’ve been scared to buy cheap, read many times they didn’t measure gain properly…

 

[fig]

I dunno...I use the TC-1 more often than the DCA75 for pinout and gain...it's a decent ballpark. No GE leakage measurement though.

 

[EGRENIER]

I dunno...I use the TC-1 more often than the DCA75 for pinout and gain...it's a decent ballpark. No GE leakage measurement though.

This one ?

3.5 inch Colorful Display Pocketable Multifunctional TFT Backlight Transistor LCR-TC1 Tester for Diode Triode Capacitor Resistor Transistor LCR ESR NPN PNP MOSFET : Amazon.ca: Tools & Home Improvement

3.5 inch Colorful Display Pocketable Multifunctional TFT Backlight Transistor LCR-TC1 Tester for Diode Triode Capacitor Resistor Transistor LCR ESR NPN PNP MOSFET : Amazon.ca: Tools & Home Improvement

www.amazon.ca

 

[Superjab71]

Thanks all, I did socket them and I put them in the way the diagram shows but I am getting some crazy sounds, a lot of squealing (and maybe even picked up a radio signal?), so I’m not sure if I messed up or it’s just how the pedal is.

 

[carlinb17]

I remembered when I built one and when used my telecaster I picked up a religious channel and thought god was speaking to me! Some interference is common with certain pedals although squealing not so much

The lug on your bottom left pot looks like there’s no solder in the #3 leg

 

[fig]

This one ?

3.5 inch Colorful Display Pocketable Multifunctional TFT Backlight Transistor LCR-TC1 Tester for Diode Triode Capacitor Resistor Transistor LCR ESR NPN PNP MOSFET : Amazon.ca: Tools & Home Improvement

3.5 inch Colorful Display Pocketable Multifunctional TFT Backlight Transistor LCR-TC1 Tester for Diode Triode Capacitor Resistor Transistor LCR ESR NPN PNP MOSFET : Amazon.ca: Tools & Home Improvement

www.amazon.ca

yes, that’s the one.

 

[fig]

Thanks all, I did socket them and I put them in the way the diagram shows but I am getting some crazy sounds, a lot of squealing (and maybe even picked up a radio signal?), so I’m not sure if I messed up or it’s just how the pedal is.

View attachment 29274

Those pins need trimming. Then try it with the cover on.

 

[MichaelW]

Any suggestion on that… I’ve been scared to buy cheap, read many times they didn’t measure gain properly…

I have 2 GM328 based testers. One was from a kit I built and one is being sold as the LCR T-7. They can both be a little finicky at times and not recognize a component but they both work accurate enough for pedal stuff. I might get 3 different readings on the same Ge transistor but I chalk that up to the temp sensitivity of those things. With silicon components it's pretty stable. But between the two testers and my DMM it's never an exact match, always a few cents difference. But it's a negligible difference.

 

[swyse]

I have 2 GM328 based testers. One was from a kit I built and one is being sold as the LCR T-7. They can both be a little finicky at times and not recognize a component but they both work accurate enough for pedal stuff. I might get 3 different readings on the same Ge transistor but I chalk that up to the temp sensitivity of those things. With silicon components it's pretty stable. But between the two testers and my DMM it's never an exact match, always a few cents difference. But it's a negligible difference.

I wonder if the germanium leakage also confuses it a bit, I wouldn't expect the designers of a product like that to have germanium in mind.

 

[szukalski]

I dunno...I use the TC-1 more often than the DCA75 for pinout and gain...it's a decent ballpark. No GE leakage measurement though.

TC-1 has leakage measurement? Iceo?

 

[fig]

TC-1 has leakage measurement? Iceo?

Does it? I’ll be doggone, it does. Now I have another comparative reference. I need to either build about 300 fuzz faces or have a big ‘ol germanium transistor giveaway.

 

[Robert]

Thanks all, I did socket them and I put them in the way the diagram shows but I am getting some crazy sounds, a lot of squealing (and maybe even picked up a radio signal?), so I’m not sure if I messed up or it’s just how the pedal is.

Sounds like it's working exactly how it's supposed to.

 

[EGRENIER]

Sounds like it's working exactly how it's supposed to.

Oops just realized I pointed him at the Fuzz Factory instead of the Fuzz Foundry. Sorry if I mislead you….

 

[Robert]

It's easy to get all of the projects confused.

If it's squealing and making all kinds of noise the transistors are most likely installed correctly.

 

[szukalski]

I need to either build about 300 fuzz faces or have a big ‘ol germanium transistor giveaway.

A fuzz face in every child's hands.. what a dream! Makes all warm and.. fuzzy.

 

[MichaelW]

Sounds like it's working exactly how it's supposed to.

Well crap.....now I need to build this too......