Ibanez ue405 footswitch schematic

[trjones1]

I just traced out the footswitch system schematic for my UE 405 Rack unit.  These things sound really great (especially the compressor and delay (AD-9) circuit), but if you lose the footswitch you're up a creek.  This schematic is not verified at all, and its the first schematic I've ever traced out, so don't blame me if this blows your unit up if you try it.  The schematic is quadruple checked, though, and I'm pretty sure its accurate.  Please forgive the handwriting.



There are five of these circuits in the foot pedal, one for each effect and the master switch.  I'm not sure what kind of diode is used, but it's small and red, looks like germanium.  If anyone has an idea please let me know.  There are places on the board for R7 and 8, but nothing in those spots; that's why those numbers are skipped.  Also, C4 and 5 had no value on them.  They are pyramid shaped caps and the markings were "1N" with a "1" below that.  Again, if anyone knows what the value of these caps are, please let me know.  Here's what they look like:



They are the pyramid shaped caps in the foreground.

For all I know this is the standard switching circuit in TS-808 era pedals. Hopefully someone will find this useful in bringing this really cool effect back to life after losing the footswitch.  Please note the C1815 transistors use a different pinout than standard TO-92 transistors.  On the C1815, the collector is in the middle (which I guess is how the Japanese do it).  Other transistors might work in this, I have no idea.

[zachomega]

Look up "flip flop" style switching.  It is indeed the same style switching used in the TS808, 9 series, 7 series, 5 series...etc...Lots of companies use this style because it is cheap and gets fairly decent results. 

-Zach 

[trjones1]

I'll look into that.  I met someone who wants my footswitch and I'm trying to figure out if its cost effective for me to make him a new one from scratch.  Can any momentary switch work in the circuit?  I see the normally open switches at smallbear are expensive compared to the little pc mounted switches, but I can't fabricate the actuators to make those work.

[zachomega]

Yes, any cheap momentary switch should work...HOWEVER...Be sure that the switch does not switch on and off if you rock it from side to side...By that I mean, make sure the switch only switches once per time it is pushed.  Very cheap tactile switches will give intermittent results at best. 

-Zach