DOD FX-17 Foot Controlled Phaser Mod - Revisited

[Paul Marossy]

I have a schematic drawn up that has some of the components labeled as they are indicated on the PCB. So here are my two questions:

1. The two caps labeled C7 & C9 at U2 (13600), are those the sweep caps?
2. If one were to possibly convert the circuit to a foot controlled phaser, what components would have to be changed?

Here's the schematic: http://www.diyguitarist.com/Schematics/FX17-Schem.pdf

[KarbonHed]

Probably too few stages to convert the LM13600 part to any kind of phaser. Though you could get a slightly different sound by tapping the Low Pass output from Pin 8. And add a resonance control by changing the 100k resistor from pin 9 to 13 to a 10k res and 100k pot.

But with a 0-5v control voltage output you could build a phaser and use the FX-17 as the sweep source for it.

For initial experimentation, take a standard phaser design and where the LFO goes into the depth pot add a jack socket so the control voltage can be used.

[Paul Marossy]

Hmm... the resonance control idea is an interesting one. As far as the phaser mod part goes, I am just trying to take Mark Hammer's idea and see if I could implement it to see how it works out. You're probably right - not enough stages to get a good phaser sound. Although, if it could sound like a Phase 45, that might not be too bad...