Monday, April 8, 2013

BOSS CH-1 mod (digital version) Super Duper Chorus

Boss CH-1 super chorus pedal.  This is the less popular digital version of the CH-1.  The older super chorus pedals are analog and sound much better.  This pedal uses a digital processor chip to create the "chorus" effects.  I opened this guy up and found some useful mods.  I changed the resistor in parallel with the rate pot.  The effect rate now speeds up to almost infinity.  One of the added toggle switch cuts the clean signal out, only allowing the modulated signal to pass ( sounds like a vibrato ).  The other toggle switch changes the chorus setting in the digital chip.  This switch makes the effect more intense and almost square-wave sounding.  To give you an idea of what the mods sound like, below is a sound clip of me playing guitar, badly, while messing with the settings.


I wouldn't call this pedal warm or lush.  More like corny, or cheesy sci-fi.  It's almost more suited for Casio keyboards then it is for guitar. 

Upon request here's some gut shots to display the mod I did.

The two toggles squeezed in there 

Rate resistor reduced to 1.8 K. you could solder bridge this if you wanted.

Tremolo switch.  Theres probably a better way to cut out the clean signal.

Pin 13 of the echo processor lifted.  The switch ties pin 13 to pins 11 &12.  This basically add more modulation depth.  In hindsight you might not need the switch.  Just lift pin 13 so it's no longer grounded and solder it to pin 12.  With pin 13 enabled, the depth control at about 11 o'clock sounds like the stock pedal would with the depth control maxed out.  

Here's the echo processor's data sheet for reference ES56028.pdf