I'm not entirely sure this is the right forum, sorry if it's not.
I've been working on some circuit experiments, seeing exactly what I expected on the o-scope out of my breadboarded oscillator, fuzz & filter circuits. Today I hooked the output of my keyboard (Dave Smith Instruments' PEK) to the o-scope to get an idea of what voltage swing I should expect from a synth output.
What I saw was a funky waveform of 60Hz (so clearly related to power supply, right?) that was about 160Vpp. This was with no detectable output level, metered or audible, when connected to a mixer. When I brought the output level of the synth up to some nonzero level, nothing on the o-scope changed. Nor did anything change when I changed the oscillator shape. This remained when I turned the synth off, and only changed when I unplugged the cord from the output or unplugged the synth's (external) power supply.
Obviously I'm missing something I should know. Can anyone enlighten me?
I've been working on some circuit experiments, seeing exactly what I expected on the o-scope out of my breadboarded oscillator, fuzz & filter circuits. Today I hooked the output of my keyboard (Dave Smith Instruments' PEK) to the o-scope to get an idea of what voltage swing I should expect from a synth output.
What I saw was a funky waveform of 60Hz (so clearly related to power supply, right?) that was about 160Vpp. This was with no detectable output level, metered or audible, when connected to a mixer. When I brought the output level of the synth up to some nonzero level, nothing on the o-scope changed. Nor did anything change when I changed the oscillator shape. This remained when I turned the synth off, and only changed when I unplugged the cord from the output or unplugged the synth's (external) power supply.
Obviously I'm missing something I should know. Can anyone enlighten me?