Delay Crazy

[enquiryband]

i want to build a delay that i can essentially push to infinity, get clean feedback that will multiply on itself in volume and then bring it back... is this impossible? is there a good delay build? i think i need a analog delay... there's so many out there...

[Mark Hammer]

1) Analog delay chips have limits on their headroom; they can only take so much signal before they develop problems.  For this reason, almost every analog delay I have ever seen in my life has some circuit portion dedicated to keeping a tight lid on the recirculated signal level so tht it never exceeds a given maximum.

2) Analog delays are imperfect transmission systems.  The more stages the signal passes through, and the longer it spends in each stage, the less it starts to resemble the original input signal.  This is partly because of the leakage that occurs in the tiny storage capacitors that make up each stage, but also because of the filtering and the aliasing that takes place (the audible side-effects of having a "stairstep" change between one stage sample and the next).  This means that after a half dozen or so repeats, the signal is usually not particularly good quality

You want a digital delay, not an analog one.

[enquiryband]

and im guessing its too difficult to build a digital delay and i would be better off buying one? i already have a boss Giga-Delay. but i was looking for something that would give me a little more flex and something i could modify

[Mark Hammer]

Although things like the Princeton chips do a great job providing digital delay for very little cost or complexity, I sincerely doubt there is anything in the DIY realm that will add to the power you have with the Giga Delay.

[The Tone God]

You can look at using a Dirty Mary / Dub Machine circuit to add repeat controls to an existing delay without having to modify the delay.

Andrew

[slacker]

I don't know any DIY delay that will do the "clean" part of what you want. Any of the PT2399 delays should be able to go up to near infinite repeats with careful tweaking, but like Mark said about analogue delays the sound gets coloured and degraded after a while because of the filtering in the pedal.

As an example of what I mean listen to this http://www.eskimo.plus.com/fxstuff/ebselfosc.mp3. If you're careful you can keep PT2399 based pedals going like the start of the clip for a very long time, but the sound isn't clean.