Modding for Boss ch-1?

[siaoguitar]

Hi fellow diyers!, my guitarist got a boss super chorus, was wondering it can be modded for more chorus/crazy stuff, any ideas what mod one can do it?

[Mark Hammer]

The CH-1 can be modded in just about all the "normal" ways that a CE-2 can be modded.

For example, you can change the delay range by changing the 47pf capacitor beside the MN3101 chip.  Smaller values (e.g., 33pf) will shift the delay range closer towards flanging, and larger values (e.g., 68pf) will move the range towards spacier thicker sounds.  Just be aware that longer delays will make the pitch "wobble" stronger, so you/he will need to turn the Depth control down.

To achieve ring-modulator type sounds, the two back-to-back 10uf capacitors (Labelled C36/C37, I think) in the low-frequency/modulation oscillator  can be replaced with a 1uf nonpolarized cap.  This will shift the speed range over by a factor of about x5, such that the fastest speed will give an elastic-like "boing" and the slowest speed will be closer to the what used to be the "bubbly"' speed.

If you break the kink between R53 (47k) and Q1, you will cancel the clean signal at output jack A, giving a vibrato-only effect.  Please note that this  unfortunately produces NO OUTPUT when you bypass the effect.  The more problem-free way to accomplish the same effect is to stick a mono plug into jack B, without any wires attached to it.  Doing this will feed a delay only signal to jack A in effect mode, and clean signal in bypass mode.

[sevenisthenumber]

I was wondering about this!

"The more problem-free way to accomplish the same effect is to stick a mono plug into jack B, without any wires attached to it.  Doing this will feed a delay only signal to jack A in effect mode, and clean signal in bypass mode.

Does that mean i just let the wires stay unconnected?

Is it a VB-2 type vibrato?

[Mark Hammer]

Jack B is for producing more spacious sounds, similar to the old Jazz Chorus amps, buy feeding wet and dry signals to separate amps.  If there is nothing plugged into Jack B, then the dry and wet signals are normally mixed together and presented as a mono signal at jack A.  When a plug is inserted into jack B, then the only thing that shows up at jack A is the wet signal.

So, you can achieve a bypassable vibrato without having to mod anything in the unit, simply by sticking a bare phone plug (ie., no wiring needed, just take it out of the bubble wrap it came in and stick it in the jack) into jack B.

Will it be like a VB-2?  Hard to say.  You certainly won't have the ramp-up effect that the VB-2 provides, but then not everyone uses that feature.  What I can't be sure of is whether the modulation speed range and depth of the two pedals is similar.  A chorus effect can still be audible even at slow speeds, but a vibrato effect requires a certain minimal speed for the pitch change to be detectable.  That means you may find only a small portion of your CH-1's speed range usable for vibrato effects.  Still, it WILL provide audible and usable vibrato, and for the price of a plug, and no soldering/unsoldering involved, not bad.

[ayayay!]

Aren't the newest CH-1's SMD though?   

[Mark Hammer]

Maybe, but if the jack arrangement is still the same, you can still get "no-mob" vibrato as described.