PT-80 Delay

A digital delay project from Scott Swartz. This is an awesome delay/echo stompbox that has received great reviews from the DIY stompbox community! Page down for sound samples.

Buy a PT80 Complete Kit. Includes all the parts and materials you need to build one, all for about the price you would pay for a PCB and parts.


Would you like a Ready to Solder Circuit Board for this project? Note: If you buy the kit, the Ready-to-Solder Printed Circuit Board (RTS PCB) is included in the kit.  You do not need to purchase this Ready to Solder Circuit Printed Board if you buy the kit.


PT-80 Sound Files

copyright 2002 by Scott Swartz. All rights reserved


After all the blah blah about how the PT-80 sounds like an analog delay, I threw together a few mp3’s to illustrate. The recording signal chain is guitar amp to Royer R-121 ribbon mic (expensive but worth it) to homebrew tube mic preamp to mixer (EQ bypassed) to Tascam CD Burner. The guitar is a 62 RI Strat, set to middle and bridge pickups. Amp is a homebrew Twin Reverb type circuit set for a clean sound with a bit of the onboard spring reverb.

The files give a general idea about the sound, but mp3 limitations wash out some of the very fine detail in the sound. You will definitely hear that it doesn’t sound like a typical digital delay though.

Hear the Sound Files

Sound File 1 – The Rockabilly Slapback

This is a short passage that starts with a few notes without the delay. I switch it in the delay, and play another single note passage, then conclude with a little Travis picking riff.

Control Settings are: Delay Time = 30%, Repeats = 25%, Delay Level = 50%.

Sound File 2 – The 175 Millisecond Atmospheric Delay

This is a sample of how I typically use delay, set for about 175 ms, 3-4 repeats, and the delay level set to give some atmosphere behind the notes. I play a thirds and sixths riff all the way though, then kick in the delay and play the passage again.

Control Settings are: Delay Time = 40%, Repeats = 30%, Delay Level = 40%.

Sound File 3 – The Maximum Delay Playing Notes For You Sound

This is a passage to demonstrate the sound quality of the repeats when set to max delay (using a 50K pot). The delay level is turned up to match the volume of the dry signal, and then I play a few descending sixths in time with the repeats to create a big wash of sound. At the end, I play a couple of single notes to isolate the repeats sound. The higher note does have some distortion, this isn’t present at shorter delay settings.

Control Settings are: Delay Time = 100%, Repeats = 30%, Delay Level = 60%.