Mark Hammers modified Chorus to vibrato effect, report

[Neutral]

Relating back to an old post of mine
http://diystompboxes.com/sboxforum/viewtopic.php?t=16318&highlight=

I successfully made some mods suggested by Mark Hammer (god bless him!) on a CE-2 copy pedal made by PSK(?).
It was a close enough copy that I could use a CE-2 schematic anyway but there are some differences.

Mods I made:

(reffer to ce-2 schem

http://home.hetnet.nl/~chrisdus/download/ce2.gif)

-Lifted R21,
    this isolated the vibrato signal from the 'chorused' delay signal,

- I hooked up R21 to a DPDT switch that switches it in and out and also switches an 8k resitor on the output to attenuate to volume increase when it is switched in.

- decreased R32 to around 2k, this made the vibrato rate increase, a lot!

- increased the Rate pot VR1 to 1meg to handle the new rate increase and give more range to the rate.


This has effectively expanded the scope of this pedal amazingly and with a flick of a switch I it is still everything it was before.
The vibrato is very much a square wave though, square wave vibrato is not so musical, albeit very sci-fi! So here's my big question.

Can anyone tell me how to get more of a sine/triangle vibrato?


Any other funky mods I could try?

Cheers

[Paul Perry (Frostwave)]

just looking at the circuit & not having any experience with it, maybe it is possible to swmooth out whatever is going to the depth pot, try a 100k at the top end of the pot, with a cap (maybe 1mfd electro) from the junction of the 100k & pot to ground. if this works and there is not enough depth try reducing the R35 to 100k.
Just guesses but somthing to try.

[Neutral]

Thanks Paul, I'll give it a crack.

By 'top end of the pot' do you mean the top on the schematic, where pin 1 of IC2 connects?

Cheers