Author Topic: A delay pedal anyone can build for cheap!  (Read 1247 times)

gcwills

A delay pedal anyone can build for cheap!
« on: June 21, 2018, 10:14:00 PM »
Hi all,
This is a project that I have just completed that I'm very pleased with and would be ideal for a beginner to pedal building.
It is based around a prebuilt echo/delay module readily available from Ebay or other online sellers for around AU$4 posted. The module has everything included - just needs a couple of 1/4" sockets, a power supply and an optional extra 50K pot.
So the only soldering required is from the module to the sockets.
Here is an image of the module:



The module uses the standard circuit from the Princeton datasheet which is also the basis for the original Rebote delay.



Not only is a delay pedal built from this module easy to build, I have been really impressed with how good it sounds. I have built most of the PT2399 based delay pedals over the years, and most of these designs deliberately roll off higher frequencies to simulate a BBD based delay. This delay module based on the Princeton application note uses less high rolloff and simplifies the circuit to only two controls. In spite of the increased high end, there is little noise evident and only at max delay settings.

More information to come......

Marcos - Munky

Re: A delay pedal anyone can build for cheap!
« Reply #1 on: June 22, 2018, 12:59:41 AM »
That's a nice project!

Found the board on aliexpress. I'm not sure how much it costs in dollars, but it's about $5.50 with shipping to Brazil based on the price in reais (brazilian coin).
https://aliexpress.com/item/PT2399-Microphone-Reverb-Plate-Reverberation-Board-No-Preamplifier-Function-Module/32816343977.html

gcwills

Re: A delay pedal anyone can build for cheap!
« Reply #2 on: June 22, 2018, 04:07:47 AM »
Thanks Marcos - yes that's the module. It seems to be sold by numbers of sellers.
Interestingly, the item you linked on Aliexpress sells for AU$3.84 posted ;)

vigilante397

Re: A delay pedal anyone can build for cheap!
« Reply #3 on: June 22, 2018, 10:50:48 AM »
So the only soldering required is from the module to the sockets.

Quote
A delay pedal anyone can build for cheap!

So you're saying this is a delay pedal anyone can have pre-built for them for cheap? :P Frankly the soldering is my favorite part of building ;D
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pinkjimiphoton

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Re: A delay pedal anyone can build for cheap!
« Reply #4 on: June 23, 2018, 06:05:58 PM »
i use these all the time in chipamp pedals. they're great.

BUT

they are set up as digital reverbs. you need to replace r28 on the board, and wire in a 50 or 100k pot to control delay time.
you end up with delay time and wet dry mix. i'm not savvy enough to hack in anything else with this smd stuff,
but yeah, on ali express they're about 3 bux shipped, ebay, around 5. for what they do, they work great.

in the chipamps i use a simple buffnblend circuit with these, and hack in a 100k pot. there's pads on the side for a 9mm alpha. you don't HAVE to remove r28 but they suggest it... gives ya more control over the short end of the time scale i guess.

other than that, these are wicked useful. i use 'em with my rubydoobies,
'
recently petey twofingers got me into chip amps. i gotta 100watt mono class d board in yesterday, runs on up to 26vdc so i'm gonna run it with a 24v laptop supply i have kicking around.

i use one of these boards for onboard delay, a couple of the buffnblends and a tonetweq boards from guitarpcb for dry/wet for the 2399 echo and belton brick reverb, and then set it up with a mosfet boost for clean, a fuzzface for crunch/normal everyday photon sounds, and a RM mongoose circuit for when i need a lot of distortion, the whole mess will fit in a 1590dd, with footswitches for the "channels", and onboard fx. love it.

plug yer guitar in one end, plug in a speaker in the other, and WANGO.

i'll try and post some shots when its done. sorry for the momentary hijack ;)
i bought three of 'em for 10.80 on ebay the other day

https://www.ebay.com/itm/PT2399-Microphone-Reverb-Plate-Reverberation-Board-No-Preamplifier-Function/183154226908?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649



this is the amp module. it will actually run on 9volts, tho you won't get the rated power out of it unless you supply it with 24v.

https://www.ebay.com/itm/TPA3116D2-100W-Mono-Channel-Digital-Audio-Power-Amplifier-Board-car-DC-12V-24V/392004590054?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

listen loud. blaze one first:
https://drive.google.com/open?id=0BzMJxNNgY3_yc0JNd0VqdmNIWEk

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gcwills

Re: A delay pedal anyone can build for cheap!
« Reply #5 on: June 23, 2018, 09:38:37 PM »
Some more information on this delay pedal.

As mentioned, pretty much everything required for a basic PT2399 pedal is included on the module with the one proviso that the input impedance is fairly low (around 15K). This means that it is not suitable for the direct connection of a guitar. To use the module for guitar there are two options. The first is to feed it from a buffered pedal which provides a low impedance output.
Another option is to use a simple buffer like this emitter follower:




The module includes a delay/echo level pot and has a fixed delay time. To allow for adjusting the delay time, R27 is the fixed reverb time resistor. Remove R27 and connect a 50KB pot to the S - G - G pads.

Here is my prototype mounted in a 1590B diecast box:







This prototype really does give a good account of itself for its low cost. Perhaps this is due to the extra high end compared with other PT2399 designs. It comes very close to the EM5 Echomachine version that I posted here some time ago. :)
« Last Edit: June 23, 2018, 10:13:35 PM by gcwills »

pinkjimiphoton

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Re: A delay pedal anyone can build for cheap!
« Reply #6 on: June 23, 2018, 10:50:25 PM »
NICE,GC!

sorry mah bad, r27. keystroked operator error or something.

i leave r27 in and use a 100k pot and its still fairly useable.
listen loud. blaze one first:
https://drive.google.com/open?id=0BzMJxNNgY3_yc0JNd0VqdmNIWEk

I stand for Truth, Justice, and the American Way. This Ain't It.
#RESIST
#FuzzyGoodness
#buildbridgesnotwalls