Help building 3-way aux switch for Eventide Modfactor & Timefactor

[cacibi]

Hello -

I need help with wiring for a 3-way aux switch (like Digitech FS-300) for use with my Eventide Modfactor and Timefactor units.

Basically it's a three switch unit wired to a stereo jack.  The Eventide can assign controls to Tip, Ring or Tip + Ring on the Aux switch.

I understand how I can wire two SPDT momentary switches for the Tip and Ring, but it's really escaping me how I wire the third switch (or if I need another kind of switch) to get the Tip + Ring option.

Is there such a thing as a 3-lug SPDT switch that will keep the Tip and Ring separated until the switch is engaged?

Thanks

[slacker]

I don't know if it helps, but there's a schematic for the Digitech FS-300 here http://www.johnson-amp.com/forum/view_thread.asp?forum=fc&threadid=1017953933

[cacibi]

helps a lot - thanks.

I guess my only question would be - do I really need the diodes?

[Mark Hammer]

If the switch works in the same fashion as the illustrated Johnson, yes.  You will note that the middle switch shown here grounds BOTH tip and ring at once. until that happens, the two have to be isolated.  When the "down" and "channel" switches are used, tip and ring are electronically isolated from each other by the diodes.  When the "up" switch is used, the tip and ring diodes are running in the same direction.

[cacibi]

Gotcha

Off to Radio Shack!

many thanks

[greatwolf]

Hi Cacibi,

I'm trying to build the same thing. How did yours go?