ShortScale.org

Edit: Finished!

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Something I thought wouldn't really be possible for me to ever make.





It wasn't simple, and took about 3 hours to build, using specially selected Polyester Box Caps.
It's a PT2399 based Digital Delay with Filtering to give it an Analogue Flavour, and also added Modulation for Chorus and Vibrato sounds.

Controls are:

Delay - Level, Feeback, Time
Modulation - Depth, Rate

Here's a rubbishy little video, ignore the crackly bits, that's something in my recording chain - the pedal is clean as a whistle in person.

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Really cool stuff mike! Delay pedals are probably the hardest pedal to make so kudos to you for building this.

sounds good too.

Awesome shit, looks like I can one day get my "digital delay pedal with momentary footswitch" made then..

Absolutely. Stutterbox ahoy.

It's got plenty of gain in the delayed signal path so it would completely lend itself to that, step on it and get a nice jagged and boosted-to-your-taste stuttery delay

Mike wrote:Stutterbox Ahoy

Aaaand we have a name already. I think I just got a buyer for the Tele (just wanted some fret pix, which I've sent), so it may not be ages away..

Only problem I guess, is that the momentary switch would have to cut the power, or in some how "reset" the feedback repeat when it's released.. or else I'd just get a bit ol' feedback mess building on itself..

Mike, that is awesome as hell!!! I'm really impressed by the level you've taken this to!!!

Hmm yeah I would have to think about it, it depends whether it is set to Self Oscillate or just Lots O Repeats, in which case they might just die out by the time you use it next. There is a resistor which can be raised to push back the self oscillation point further on the feedback and just give you more non-infinite repeat numbers. I guess the other way to do it would be to have the pedal built with a buffer (I could make a layout for this) and build the momentary switch into it such that the input to the delay chip is normally grounded and that the momentary switch "ungrounds" it by breaking this connection, thus the delay circuit only works when the pedal is depressed. It needs some thought.

I imagine you're not bothered by the modulation section which would remove one of the op-amps, two of the pots and a chunk of other bits of circuitry, which is good because if we had to go with the "electronic switching" method I described above that would involve adding a CD4 series CMOS chip to the thing. Momentary switching without grounding the delay circuit when not in use would be possible using this layout I've built with some crap removed.

mezzio13 wrote:Mike, that is awesome as hell!!! I'm really impressed by the level you've taken this to!!!

Cheers man, although I'm just building and tweaking. The design was by a really smart bloke on the Diystompboxes forum, I just built it and did some layout design/debug and tweaking to my taste.

Sounds tricky.. shelve it for the minute, I really should pay off all/most of my overdraft before I buy fun things..

Doog wrote:Sounds tricky.. shelve it for the minute, I really should pay off all/most of my overdraft before I buy fun things..

Yeah, we're just chatting mate. I'm not reaching for the soldering iron or anything

Wow, what a result!

A beast of an achievement there, Mike... sounds great, sir!

You should have seen the smile on my face when it fired up the first time and burst into loud-ass self oscillation

I can imagine...

There won't be many delay pedals out there on perfboard, either.

I think that's the bar well and truly raised for Shortscale DIYers

did you design the circuit yourself

Did you read the thread?

i did but i missed that post, doh

This is brilliant Mike, definitely next level.
The modulation does sound very anolog, and coupled with the delay its a shoegazers dream. The ammount of delay to hand is enough for most users too. It sounds ideal for the 'third hand' as well.
I would be interested in purchasing one of these, when im a bit better off financially!

If you dont eventually set up in trade at some point with your work i'll be very disappointed.

Beautiful, I've been meaning to do the same. It doesn't look like you decided to keep the tails switch, that's connected to the cmos chip that's not in your circuit. I like this variation a lot. Have you seen the Magnus Modulus, it's a similar take on the whole PT2399 chip.

0.59 .... "rape & death"

... you should definitely call the pedal that !

sounds ace Mike... mad skills !! wish I could do what you do... loving your work....

looks great Mike! I can't hear atm, cos I'm at school. Have you taken a look how the guy from DIYStomp changed the filtering stage in comparison to the schematic found on the PT2399's specsheet?

I'm a bit familiar with those chips, I have a ping pong pedal that utilizes two of these (you should definitely experiment with that, its a great sound!) but I have another that is relatively basic and similar to the specsheet's circuit (found on roachello's cadillac-looking delay pedal) The modulation business is highly relevant to my tastes.