Modifying a TS7 for remote switching?

[hybrid]

Hi, all

I've got a modded TS7 (courtesy of Joe Bodenhamer... fantastic pedal!) and i'm integrating it into my rig with a GT-6 and using an Axess Electronics CFX4 to remotely switch the channels of my Mesa F-30 via MIDI. I have an extra relay output (or two) free on the CFX4, and i'm wondering if i can modify my TS7 to be switched remotely using the relays in the CFX4.

Has anybody modded a Tube Screamer (and specifically a TS7) to work with an external relay switcher? I've done a few searches and didn't find exactly what i was looking for.

Thanks for any help!


darren.

[cheezit]

The switching you are looking for is completely independent of the TS7 audio circuit.  I'd recommend building a separate box which does remote-controlled loop switching (try looking at RG's and ToneGod's articles on the 4066 family of chips), and plug the TS7 into the loop.  If you get that working like you want, you could try building it into the TS7 case as a "daughterboard". 

You could also try to take advantage of the TS7's existing switching circuitry, assuming the bypass mode is decent.  That'd be a dirt-simple add-on of a control jack.  But typically those are momentary switches, where the Axxess does a "latched" type of switching, I think, so you'd need some control circuitry to translate a transition from "on to off" and "off to on" into something like a 50ms period "on".

The other thing to watch out for, regardless of how you do it, is ground loops.  This could generate hum, depending on how you have the Axxess routing your signal.

[hybrid]

Thanks for your response, cheezit!

I'm really trying to keep it as simple as possible, without having to build any additional external boxes if i can. I'm definitely looking at modifying the existing switch with an external jack that can be run to the CFX4. Each channel on the Axess CFX4 can be set up to operate as latched or momentary, which is perfect. It also doesn't run any audio on its own, and all the relays are isolated, so ground loops are apparently not a problem.

The TS7 isn't true bypass, but it doesn't bother me being in the chain when it's switched off. I'll mainly just be turning it off for the clean channel.

Are there instructions or a diagram somewhere for how to hook up an external switching jack to the TS7's internal switch?

[cheezit]

Well, it would help to find a schematic that includes the switching circuit.  But it should be straightforward anyway----I had a TS5 with a bad switch, and it's a dirt simple pcb-mounted part.  Quick and dirty approach is to open up the pedal and with the power on try shorting the traces around where the switch is soldered on, just using a wire.  Once you find them, you can just tack on a pair of wires, one to either side, and wire them up to a stereo 1/4" jack.  If one side is ground, you can use a mono jack.   BTW, if it were me I would not drill any holes in your TS7 until I had something working.