Rebote Delay/Chorus mod!

[idlefaction]

hey all.  here is a simple mod you can do to your rebote delay to make it a chorus/delay.  it will work on anything using the PT2399 chip.

the PT2399 uses a resistor to ground to set its delay time - the circuit generally has a minimum delay time resistor in series with a pot for delay time.  i used a triangle wave LFO driving an LED/LDR, with the LDR switchable in parallel with the resistor.  i had set the resistor at a value of 1k and the pot at 25k - this seemed to give a really nice chorus sound and allow a good range of delay times without  getting too grainy.

one really super nice thing about this setup is that the delay time is only being changed by small amounts at any position of the delay time knob - so you can have it in delay and chorus mode at the same time!!!  if you get the delay time really short it even sounds quite flangey, try 470 ohms or even smaller for the min delay resistor if you'd like to be able to get flanger sounds too.

sound sample:
http://b.wadda.org/tmp/rebote_chorus.mp3

the sample goes faster delay time no chorus, faster delay time w/chorus, slower delay time no chorus, slower delay time w/chorus.   :twisted:

[Ansil]

thats some wicked nice stuff. there and a great idea. i am going to have to do that.

[Fp-www.Tonepad.com]

VERY NICE!

Fp

[12afael]

I think the deluxe memory man has a similar stuff.

[marrstians]

do you have a drawing of what parts you put in what part of the circuit?? could you just use the chorus type setting by itself?

[RJ]

hi guys, sorry to bump an old thread like this...i'm not sure if idlefaction still browses around here, but i thought maybe somebody else might have experience with this mod.

i'm building a second rebote delay....loved the first one, gave it to a pal.....this time around i've been digging through the archives for mods or changes to make it an even cooler pedal.  after hearing the sound clip posted above i definitely want to do this chorus mod!

i'm using an xr2206 for the triangle wave but i was wondering what frequency this should be at?  would i just set this triangle wave for one slow setting, like 10 hz or 1 hz or something?  and is a function generator chip an ok way to go about this?  can it drive the led/ldr combo directly?

thanks for the cool idea, idlefaction.

[ExpAnonColin]

You can do it with an XR2206 if you want, but I would just use a dual op amp schmitt trigger/integrator pattern...  yeah, frequency would be about 1-10hz.

-colin

[RJ]

hi colin, thanks for the reply!  

i like the idea of using a dual opamp for the lfo....i found a few simple looking ccts by googling but couldn't get any of them to work, ha.  does going the opamp route for an lfo require the use of a split or dual power supply?  i mean do i need a positive and negative voltage for the opamp to make a triangle wave?

thanks for verifying the frequency!

[Frankli]

Hi!

Sorry, how to conect the led in circuit? :oops:

Thanks

Frankli