Hello transistor expert. Found these at my local electronic store. "2N211, 8120 NJS" Germanium NPN. They have a lot of NOS transistor from when the shop open . Any idea which brand is this one ?
Thank you
Even If I don't have the correct voltage on some pins, I will mark the post as solved because the noise issue with all 3 of my pedals has been solved by cleaning all the sticky cheap flux on the boards with 99% alcool and tooth brush. shame on me for buying aliexpress flux :cry:. thank you for...
i've swap the tl072 of IC1 and i still have the same voltage. I also noticed on that post that IC2 and IC3 have double the voltage on some pins.
https://forum.pedalpcb.com/threads/unicab-no-sound.20474/
IC3 middle
1: 8.6
2: 8.6
3: 8.6
4: ground
5: 4.5
6: 4.6
7: 4.6
8: 9.2
IC2 top
1: 8.6
2...
Pin 5 of ic3 seems to max out at 3.33. pin 3 of ic1: what could cause that ? Non inverted input 1 so is it the chip itself that could be bad ? R3 is 10k than the cap . Could something "drain" the power ?
Soaked (99% alcohol) and cleaned with a toothbrush. Cold result, waiting for the pop to comes back. There's so much crap on the PCB, I don't know if you can see in the picture. I don't know what happened beside using aliexpress flux.
IC1 (BOTTOM)
1. 4.38
2. 4.38
3. 1.15
4. 0
5. 4.39
6. 4.39...
so i removed the pcb from the enclosure, same thing: Pedal works fine for a while, and start to make noise after several minutes. If I bypass the pedal, no noise. wires is away from the pcb and doesn't seems to be the problem. It's really a popping crackling noise now. I also use the same wires...
I grounded both in and out with the PCB, the case is bare metal so it's also ground. The noise still appear when the effect is out of the case . I will still shorten the wire to give it a try