David_NC
Super Member
I like to use my remote to turn on and off my entire system, but I don't think it's such a good idea to run power amps through the internal relays unnecessarily. I also don't like the idea of paying $200-400 for a SCR-3 when all I'm going to do is use the switched outlets.
I'm finding minimal to zero information on the SCR jack on the back of my newly acquired C31V, other than it's a 24VDC output. A straigh-through serial cable with all 9 pins connected and a multimeter is all that it took to figure out all I needed to know. Basically, I want a DC trigger to activate my IoT relay.
These sell for around $25 and will activate with a range of AC and DC voltages. Basically, I found the two pins that are powered when the C31 is turned on, soldered two wires to the correct pins in a DB9 male plug, and connected them to the trigger inputs on the IoT (the green terminal block on the side). I also noted the two pairs that are controlled by the front panel speaker switches. These could be useful if I ever do need a relay to switch speakers on or off or for other functions unrelated to speakers that I want to control remotely, such as turning off a power amp when I'm using the headphone jack on the C31, etc.
Hopefully, this will be useful to others wanting external triggers for older McIntosh preamps. If there's any interest, I'll post a diagram of which pins control what functions.
I'm finding minimal to zero information on the SCR jack on the back of my newly acquired C31V, other than it's a 24VDC output. A straigh-through serial cable with all 9 pins connected and a multimeter is all that it took to figure out all I needed to know. Basically, I want a DC trigger to activate my IoT relay.
These sell for around $25 and will activate with a range of AC and DC voltages. Basically, I found the two pins that are powered when the C31 is turned on, soldered two wires to the correct pins in a DB9 male plug, and connected them to the trigger inputs on the IoT (the green terminal block on the side). I also noted the two pairs that are controlled by the front panel speaker switches. These could be useful if I ever do need a relay to switch speakers on or off or for other functions unrelated to speakers that I want to control remotely, such as turning off a power amp when I'm using the headphone jack on the C31, etc.
Hopefully, this will be useful to others wanting external triggers for older McIntosh preamps. If there's any interest, I'll post a diagram of which pins control what functions.