Picture of Digital Delay Pedal
Building guitar pedals is a time-consuming, often frustrating, and expensive process. If you think you will save time and money by making your own digital delay pedal, I highly advise you to read R.G. Keen's page on the economics of pedal building. However, if like me, you are obsessive, enjoy messing around with electronics and want to make something that looks and sounds uniquely your own, continue reading ahead... just don't say that I didn't warn you!

Follows are detailed instructions on how I made my own digital delay pedal. I must admit that I used a laser cutter as an integral part of the process, but I feel most of the tasks that I am using it for can be performed with many more modest tools. My focus of the Instructable is not so much in the assembly of the circuit, but the assembly of the case, as this is where the real crux of the problem lies. Cramming a lot of things into a little enclosure is not particularly easy. Yet, it's my hope that these instructions will help in some way to simplify the process.

Short Delay:

Long Delay without Feedback:

Long Delay with Feedback:

Step 1: Go get stuff

Picture of Go get stuff
You will need:

(x1) "BB"- sized Steel Enclosure
(x1) PT2399 Echo Processor
(x1) TL072 low noise op amp
(x1) LM7805
(x3) 100K potentiometers
(x1) 50K potentiometer
(x1) 5K potentiometer
(x1) PCB
(x1) DPDT stomp switch
(x1) SPST toggle switch (SPDT okay)
(x1) Power jack (with cut-off)
(x2) 1/4" mono jacks
(x5) Knobs
(x1) sheet 1/16" santoprene rubber (McMaster-Carr 86215K22)
(x1) sheet 1/8" cork

(x1) 100uF
(x3) 47uF
(x1) 4.7 uF
(x6) 1 uF
(x3) 0.1 uF
(x2) 0.082 uF
(x3) 0.0027 uF
(x2) 0.01 uF
(x1) 100 pF
(x1) 5 pF

(x2) 1K
(x11) 10K
(x2) 15K
(x1) 100K
(x1) 510K
(x2) 1M
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DanieleP12 months ago

will be hard but i will do it!

TiagoC62 months ago

hi, is the feedback infinity? how much millesecons are the time? thk

colinrobot3 months ago

Hello Randofo , I am very new to all this What Voltage are the Capacitors used and will 1/4 w metal film Resistors do the trick? .. sorry if that sounds dumb

RandyB77 months ago

Haven't looked at all 69 previous comments to check if someone caught this - but you have a terrible mistake in your last step. The heading should be "Plug and Pray." Otherwise, nice if incredibly anal job. Much as I love tools, not getting a laser cutter anytime soon.

jeffrey3237 months ago

Like this pedal, thanks for sharing..I have a blog for guitar and pedals too. welcome to visit: www.guitarever.com

Hi are the potentiometers linear or logarithmic?

mangini1 year ago

Nice Job, Pretty Pedal. It looks like you spent a good deal of time working on both the electronics and the object. Some day I should be so focused…

Question for you: I think I would like to use this IC PT2399 for a non-music project, from what you have considered do you think it would be pretty straightforward to make a circuit that is 100% wet (so just passing though the audio with a delay - no feedback, no repeats, ) with 200 or more msec delay? And adjusting the delay a la 0, 50, 100, 200, etc msec? Controlled with a micro controller? Feel free to answer any or all parts.

And again congratulations on the pedal - You Made That !!!

randofo (author)  mangini1 year ago

You would need some circuit or chip which can change the resistance to the delay pin via a microcontroller.

Once you figure that out, I do not see why the rest should not work.

pats132 years ago
Hello! Great instructable! Can i use this pedal for a bass or it is only guitar compatible? Thank you in advance!
azureharri2 years ago
Thanks. That's awesome. :D
azureharri2 years ago
Does the IC need programming?
Didn't see anything much about it on here so I wasn't sure.

Great instructable, by the way.
I was thinking of using this as a resource for my A Level project. :)
randofo (author)  azureharri2 years ago
It does not need programming. The cheap is designed to perform this function.
randofo (author)  randofo2 years ago
what is the capacitor value after the 1k resistor coming out of pin 14?
what programme do you use to open the files?
randofo (author)  Basementjacks2 years ago
I used Corel.
having trouble finding a power jack with cut off. help please :) thank you!
randofo (author)  Basementjacks2 years ago
This one looks like what I used:

I don't remember exactly. You should be able to maybe find something at Radioshack.
where abouts did you order the parts from? i cant find the casing, the rubber sheets or the cork
randofo (author)  Basementjacks2 years ago
The case I got from Small Bear, the cork I got from a local craft store, and the rubber came from McMaster.
Hi im delighted to find this project as i needed something for my end of year project for college, just a few questions if you wouldn't mind answering: what type of capacitors are these? e.g panasonic, aluminium? and do i definitely not need an arduino board? also, would you recommend using the full casper schematic or did you make your own for personal reasons or because it was a better layout as such than the original schematic? Thank you!
randofo (author)  Basementjacks2 years ago
some are ceramic and others electrolytic. Usually, the dividing point is 1uF.

You can use theirs. I changed a few parts to my liking, but nothing too significant.
I really need your help. Your work is awesome and it'll be very much helpful to me. I'm sorry but can you put up some of your conclusions in doing this product since you're the one who've made it. I just really need it for my research. Please be kind to me. Hehe. I'll appreciate your feedback. Thank you. =)
randofo (author)  AljonSalvatore2 years ago
What sort of conclusion?
crrollyson2 years ago
What kind of lazer cutter do you have/recommend?
randofo (author)  crrollyson2 years ago
I have been using an Epilog. I don't have much experience with others, so cannot recommend them.
RedBinary3 years ago
You have the whitest foot that I have ever seen.
randofo (author)  RedBinary3 years ago
It's almost as if I am wearing a white sock.
danricramz3 years ago
only my comment for this project is only the capacitor uf. has indicated. but the voltage does not. so it can be over voltage the IC and it won"t work properly.. please reply me as soon as possible thanks.....
charlez953 years ago
can you send to me the full schematic ??
thanks in advance
randofo (author)  charlez953 years ago
See the links above for more information about the circuit.

Resistors are 1/4 watt. Capacitor voltage does not matter much... try 16v+
charlez953 years ago
how many volt does cap have ??
what watt is the resistor.
Gizah3 years ago
What's the cap symbol with no indicated value after the 510k resistor? And where do you use that SPST you mention in the parts list?
randofo (author)  Gizah3 years ago
5 - 10pF. You can probably even leave it out.

The SPST switch I was using as a power switch. You can probably use stereo jacks instead of mono such that when you plug in a mono guitar cable have the extra stereo connector complete the circuit by making the ground connection.
nikolozj4 years ago
oh! I thought "better diagram" meant the one you drew but with better quality. I just wanted to have a better picture of your own diagram, even tho you said that it's almost entirely based on casper one, I still wanted to look into it with its all details. I can't recognize some parts of your version of diagram because of low quality of file, even if I save it on disk and then zoom it, then the quality gets worse and I can't see clearly for example cap marks or any other detail... I'm a beginner amateur electrician so I need to study diagram carefully to get it. please let me have your version of diagram with better quality and sorry for causing so much trouble!
randofo (author)  nikolozj4 years ago
nikolozj4 years ago
could you please update "better diagram" link? thanks!
randofo (author)  nikolozj4 years ago
nikolozj4 years ago
hi! good job. but I noticed in video that it has some "switch noise" when you switch it. is that avoidable?
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