Boss CH-1 Mods
April 4, 2005:
I have performed a couple of mods on this pedal. The delay range and ring modulator. For the delay range mod, I used 56pf. Not a huge change but it sounds a little thicker. For the ring modulator, I used the suggested 1uF nonpolarized cap. If you plan on doing these mods, please read the disclaimer on the front DIY page before continuing.
Modifications:
(Courtesy: Mark Hammer)
The CH-1 can be modded in just about all the “normal” ways that a CE-2 can be modded.
Delay Range
You can change the delay range by changing the 47pf (C10) 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 will need to turn the Depth control down.
Ring Modulator
To achieve ring modulator type sounds, the two back-to-back 10uf capacitors (C26/C27) 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 what used to be the “bubbly” speed.
Chorus/Vibrato
Before getting in to this mod, let’s take a look at how the outputs work both in mono (Output A only) or in stereo (Outputs A & B).When you only plug into output A (Mono) you get a mix of dry and wet sounds–typical chorus. When you use both outputs, you get dry out of B, and wet out of A. And when using both outputs, if you hit the bypass pedal, you get all dry from from both outputs.
| Output A | Output B | |
| Mono | Wet & Dry | Not Used |
| Stereo | Wet | Dry |
| Bypassed Mono | Dry | Not Used |
| Bypassed Stereo | Dry | Dry |
If you break the link 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.
