GEO Programmable FX Switcher Change?

[wokeupfalling]

On GEO's Programmable FX Switcher, Is it possible to change the footswitch part of it to send a Ground signal to the relays rather than a V+ signal??

I'm not up to speed on the CMOS stuff yet, any ideas?

Thanks!!

[R.G.]

Sure.
But we need to know exactly what you mean. There are multiple footswitching systems at GEO. Do you mean this one?
http://geofex.com/Article_Folders/fxswitchr/fxswitchr.htm
Because if you do, look at figure 8 (Relay Drivers) for how the relays get a pull to ground from that positive signal.

If you mean the latched part before the relay drivers, sure, you just stick an inverter in series with each signal. Suitable inverters are the CD4049 and some octal bus driver/inverters.

The answer is yes, but to say exactly how "yes" more info is needed.

[wokeupfalling]

Yes, that's the one - I didn't look past figure 7...   Should I be concerned about the power of the relay drivers, or are they pretty strong? Could there be a negative effect having the relay drivers on the other (far) side of the DB-15 cable? 

Also, I was unsure about the diodes right before the 74C373, what should those be?  I'd like to try running two 74C373's linked together - what are the odds that would work?  Ha ha, i'm full of questions!

RG, I tried using the transistor + diode switching we talked about (did you get my private message?) but it wasn't strong enough to drive my relays - I'm thinking this could be a safer bet?  This project has gone from exciting to a headache!!

Thanks for the help ~