gte975n

a2dconverterguy thank you for the schematics. I ended up building the resistor circuit with a Mesa Mark Five:25 and only got the EQ to switch and nothing on the channel. I built the relay circuit and it functions beautifully. I do have three followup questions for you if you don't mind. I dabble in microcontrollers but don't fully grasp all the nuances of dc circuits. Your help is greatly appreciated! Are the LED's necessary in the circuit (i.e. does it help prevent current spikes into the helix?)? Could a SPDT solid state relay also function well in this application? I was trying to think of a way to elimnate the need to have an external power source for the relay circuit. One of the things I thought about was using a expression pedal or CV out on the helix to power the relays. Do you think this would work? The expression pedal has about 3.3V across the contacts and the CV has a 5V. I know they make lower coil voltage relays but I'm not sure of the current draw the relay circuit could put on the expression pedal or CV circuits versus what they can handle. The power consumption ratings on the coils seem to be very low (in mW) but I'm not sure if they would work. Thanks again for your help. FYI, I contacted mesa about this directly. They were trying to be helpful, but they ended up sending me the information in these threads. It's really a Line6 Helix issue and not a Mesa issue, but I thought I'd reach out for their assistance. ~josh