I just bought a secondhand PAiA Theremax, and I'm very pleased with it. One thing is bothering me though. The Gate/Trig light comes on when I switch on the theremin and stays on. I was expecting it only to come on when I move my left hand rapidly. Turning the velocity control doesn't make any difference as I thought it might. Is there something I need to adjust or is it faulty? Any suggestions greatly appreciated.
Theremax gate/trig light always on
Posted: 10/3/2010 6:22:37 AM
Take a multimeter or an oscilloscope and check pin "K" of the circuit board. There should be normally 0V and a short peak (up to +1V if you lift the hand rapidly up from the volume loop).
Check the voltage at pin 8 of IC 1. Should be around 0.5V. Check the voltage at pin 9 of IC1. Should be below the voltage at pin 8.
Please check this and report back.
Check the voltage at pin 8 of IC 1. Should be around 0.5V. Check the voltage at pin 9 of IC1. Should be below the voltage at pin 8.
Please check this and report back.
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