FFX Delay Prototype

[culturejam]

This is not anywhere near final art or even the actual name of the pedal, but I liked how this came out. Been working on the circuit since June 2021, and it's just about done. Few minor tweaks left, but it's just part values at this point. I'm really happy with how it turned out. Quick demo: https://vimeo.com/manage/videos/679760929

Since this is a DIY forum, I'd like to share some of the details on how this is not just another "by the datasheet" PT2399. A long time ago, I played around with a super-simplified PT circuit that didn't have input or output buffers and only used one of the PT's internal op amps. The goal was a delay with the minimum of parts. It worked out great, and was a really fun DIY project, but I wanted to take that idea to the next level.

But I wanted to keep the idea of just using the one internal op amp, and making up for it with some external filtering. So I added two filters in series for the delay output: a Sallen-Key active filter that you'd normally see in an analog delay, and also a simple one-pole variable low-pass filter. Then I added a simple LFO to provide some modulation (modified version of the EA Trem LFO).

I used my little Neje Master 2 hobby laser (5.5W) to do the art on the box. Backfilled with acrylic paint. 

[cooder]

Superb and snazzy! Love to hear some samples!

[culturejam]

Love to hear some samples!

Coming soon!

[nzCdog]

Cool to have a sneak preview like this of whats been brewing in the FFX labs! Your enclosure looks great too

[jimilee]

Hotel Echo, nice! The tone knob is a great feature.

[culturejam]

Cool to have a sneak preview like this of whats been brewing in the FFX labs! Your enclosure looks great too

I will be posting an update to the forthcoming JFET boost/drive project as well. I wanted to get the delay done first because it's a lot more hassle upfront.

[culturejam]

Here's a quick demo from my guitar lesson the other night:

https://vimeo.com/manage/videos/679760929

[Bio77]

Looks cool!  Did you experiment with other LFO circuits?  I'm interested in opinions on which LFO circuits sound best in a PT delay. 

[culturejam]

Looks cool!  Did you experiment with other LFO circuits?

Not really. This one sounded good right out of the gate, so I just went with it. Madbean has done several modulated PT projects, so you can check those for some additional ideas that have been well tested.

[Martan]

Sounds really good. Maybe a stupid question: Is the drive coming from the pedal due to the circuit design or is that the amp?

[culturejam]

Sounds really good. Maybe a stupid question: Is the drive coming from the pedal due to the circuit design or is that the amp?

Definitely the amp.

[cooder]

Sounds great, thanks for demo!

[nzCdog]

Here's a quick demo from my guitar lesson the other night:

https://vimeo.com/manage/videos/679760929

Dang. Those repeats are dreamy. ❤️