Hey everyone. I decided to dip my toes into pedal building, and decided to start with a Mudbunny 2020.
The actual build went pretty quickly and smoothy, until I ran out of my favorite solder, and found some Bernzomatic rosin core in my supplies that I ended up not liking at all. But I finished everything, and after reflowing some joints I got the board LED to light up.
I plugged it into my amp, and there is a lot of noise with it off, which should have been bypassed. The noise increases with the Volume, and alter with the Sustain and Tone pots. When I turn it on, it makes a constant loud whine that modulates with the Volume, Sustain, and Tone pots.
Here's a video of the noise and whine.
https://youtu.be/xZmly0GMrAY
I took a look at all the solder joints and reflowed some that seemed dull, and checked continuity, but no dice. I'm pretty much stuck, and have no idea how to fix this.
Here's the voltage measurements:
DC +: 8.75 V from the wall wart
All transistors are 2n5088.
Q1
C: 4.036
B: 0.635
E: 37.5 mV
Q2
C: 4.05
B: 0.634
E: 37.4 mV
Q3
C: 3.98
B: 0.63
E: 37.8 mV
Q4
C: 4.774
B: 1.44
E: 0.862
The actual build went pretty quickly and smoothy, until I ran out of my favorite solder, and found some Bernzomatic rosin core in my supplies that I ended up not liking at all. But I finished everything, and after reflowing some joints I got the board LED to light up.
I plugged it into my amp, and there is a lot of noise with it off, which should have been bypassed. The noise increases with the Volume, and alter with the Sustain and Tone pots. When I turn it on, it makes a constant loud whine that modulates with the Volume, Sustain, and Tone pots.
Here's a video of the noise and whine.
https://youtu.be/xZmly0GMrAY
I took a look at all the solder joints and reflowed some that seemed dull, and checked continuity, but no dice. I'm pretty much stuck, and have no idea how to fix this.
Here's the voltage measurements:
DC +: 8.75 V from the wall wart
All transistors are 2n5088.
Q1
C: 4.036
B: 0.635
E: 37.5 mV
Q2
C: 4.05
B: 0.634
E: 37.4 mV
Q3
C: 3.98
B: 0.63
E: 37.8 mV
Q4
C: 4.774
B: 1.44
E: 0.862