Deep Blue Delay question

[Travis]

Hey guys! I really want to put a filter inside the "repeat loop" of the deep blue delay. Basically I want it in the repeat loop so that the filter is applied over and over to each repeat

I'm having some difficulty figuring out exactly where I should put it in, either on the schematic or Mark's layout

Any help would be greatly appreciated :)

[Travis]

Anyone?

[KT]

Any news? I'm also interested cause I want to add an fx loop in a delay pedal. And then for example add a pitch shifter in that loop so that the repeats are pitch shifted but not your main signal. Is this possible?

[Frank_NH]

Here's the pt2399 datasheet:

http://www.diyaudiocircuits.com/wp-content/uploads/2012/09/2399.pdf

It would seem that the delayed signal output is on pin 14 (output of LFO2), so try attaching a filter there.

[induction]

Yes. The delayed output comes ftom pin 14, goes through the repeat pot, and feeds back into pin 16, which is the input of the chip. So it could be inserted anywhere in the path between pins 14 and 16. Just in front of lug 3 of the repeat pot could be a convenient spot. Where you place it may have a significant effect on the operation of the filter, so you'll have to experiment to find what works best.

Of course, there is filtering already built in to the circuit. I think it's determined by the components attached to pins 9 - 13. So you could mess around with that, too.

A lot depends what kind of filter you want to add. This is really a design question, so nobody can answer what's best without knowing what you want to achieve.

As usual, I suggest you play around with it on a breadboard and decide for yourself.

Edit: Just realized I'm responding more to Travis's question, which is a year and a half old. Adding an FX loop is a similar story, though. I'd say to start with inserting the loop just before lug 3 of the repeat pot and see how well that works. You may or may not need buffering at the send and return. You'll have to try it and see. Good luck.