I read in the pages about diy stompboxes that delay boxes are not something you are probably going to make yourself and save money. Surprised was I then to found some feasible delay projects on that same generalguitargadgets.com There's the AD-3208 from Ibanez, a real analog delay. There some biasing and trimpots involved and as I had enough of that for a while, I opted for the digital PT-80

The heart of the matter is this little fellow, PT-2399:




The PT-80 is not a analog but a digital delay, simulating analog response by extensive filtering. The PT2399 really is an dedicated echo chip, so there must be some use for the other 50 or so components.

Here's a lo res video of me fiddling with the control more than really playing



The board is in fact the largest pcb I've ever made and populated, maybe this is what inspired me to take greater care while soldering.



It's possible to run it at 9V, but better performance is guaranteed at 18V or 24V. Still have to shop for a decent wall wart.

Very important when you build the PT-80 is that you follow the below advice from Mark Hammer on the diystompboxes forum -- replace the 22k resistor that connects to pin 12 of the PT2399 with a 10k, 12k and 0,015-0,022uF cap twisted together. Either end of the resistors go where the 22k goes, the remaining end of the cap goes to ground. This limit the bandwith, though hardly noticeable, but fight the oscillations. Some oscillation at maximum repeat settings is unavoidable.

I might connect it through a switch to ground to restore full bandwith when playing with lower repeat settings. You can see the still unconnected leg of the cap on the above picture in the lower center of the picture.



Me playing a bit against a long delay: