Build Your Own Clone Message Board

Hello

I have a lil beaver triangle. Sounds is bad and very quiet at the output, nothing unless all 3 controls dimed. Signal actually decreases through the gain stages. I am colorblind so have difficulty easily seeing mixed up resistors but always used a multimeter and did not have any extra resistors at the end. Works fine in bypass.

Voltages at the transistors:

Q1
C 4.02
B 0.62
E 0.02

Q2
C 8.89
B 1.52
E 0

Q3
C 7.79
B 1.34
E 0

Q4
C 5.96
B 1.56
E 0.91


Also, I have these germanium transistors, which of these would make good replacements for Q1-Q4 if I tried? WOuld the order matter?

the ge trannys are AC130 rated Hfe 160, 110, 70 and 60

Yeah, those Q2 & Q3 collector voltages are very high, and so are their base voltages, which should be right about 0.6V. I can't see any resistor mistakes, but if you used a multimeter to check them, I wouldn't expect to.

You might have a couple of bad transistors, but that is quite rare. Much more likely is the possibility of a couple of weak solder joints. I would carefully work through THIS PROCESS, inspecting your joints under magnification and correcting any problems you find. But reflow all the solder joints, no matter how good they look.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

I reflowed the whole board with no improvement. I eventually tried replacing the transistors and when I replaced Q3 it started working great. I can't get.it above unity gain but I think that's the germanium. Which transistor should be higher gain for volume?

Did you only replace Q3? Germanium transistors are much too low in gain to work well in this circuit. I would go with 2N5088's or 5089's. Readily available and often used in Big Muff type pedals.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

All 4 transistors

Sent from my SM-G986U1 using Tapatalk

Because of the low forward voltage threshold of Ge diodes, you will lose considerably more signal through them, so expect significantly lower output volume at a given volume pot setting. But there's no reason they wouldn't work in the circuit, and you may be able to adequately compensate by dialing up the volume.

Sorry for the slow response--missed seeing your last post response.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

They sent me all 4 new transistors

Sent from my SM-G986U1 using Tapatalk

And how is the pedal running now?

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2