bloke_zero
New member
I'm having some issues with my Duocast build - there is a terrible jagged hum overwhelming the base sound.
The low cut works, the lo channel works (but with a massive hum) and the hi channel seems to have no effect. I can't see any solder bridges and the parts all seem correct. But voltages not quite right - I'm getting 8.4V and 33V on the switch. Could the 50 year old mallard OC71 be dead? Or my BC549C wrong way around? I assume the red dot above the leg on the OC71 goes next to the square on the PCB?
Sound passes through and the LED's light correctly.
The solder side has some rosin but I've checked carefully with a jewellers loupe for bridges. Apologies for such an ugly build!
The low cut works, the lo channel works (but with a massive hum) and the hi channel seems to have no effect. I can't see any solder bridges and the parts all seem correct. But voltages not quite right - I'm getting 8.4V and 33V on the switch. Could the 50 year old mallard OC71 be dead? Or my BC549C wrong way around? I assume the red dot above the leg on the OC71 goes next to the square on the PCB?
Sound passes through and the LED's light correctly.
The solder side has some rosin but I've checked carefully with a jewellers loupe for bridges. Apologies for such an ugly build!