Excellent walkthrough of a PT2399 delay circuit

[jugglindan]

From DIY Guitar Pedals:


It dives into quite a bit of detail, but avoids getting bogged down in the math. But rest assured, all the math is in the build doc for the PCB

I am planning to build a PT2399 delay soon, so this video is very timely.

[Bakersdozen]

Sweet, I'm going to watch this tonight. I've got 2 chips coming for this reverb pedal.

[jugglindan]

At a cursory glance, the schematic has a similar topology to the Deep Blue Delay, but that is likely because the spec sheet for the PT2399 dictates what a lot of the circuit will look like. But just like the DBD it keeps the dry signal out of the digital circuit, mixing it back in with the wet signal at the output opamp buffer.

This is basically the circuit I planned to build, so I will go through the schematics for differences and design choices soon.

It looks like a good delay though with easy to source parts and PCBs. So far I have seen PCBs from Aion, Madbean, and DIYGP, along with stripboard layouts.

[jugglindan]

A bit more reading on this family of circuits. It seems that a whole bunch of PT2399 based delays trace their origins to the Rebote delay v1, which in turn is nearly identical to the circuit given on the spec sheet for the PT2399. This family of delays includes the Mad Professor Deep Blue Delay, the Earthquaker Devices Disaster Transport Jr, and the Wampler Faux Analog Echo.

Of course, the problem with identifying this is that now I am not sure which one to build. Maybe something with the option to modulate the repeats...

[Bakersdozen]

Good explanation in the video. Makes me think now this chip could open up options for tap tempo and blinking led feedback for delay ms rate

[jugglindan]

There are definitely layouts around for tap-tempo add-ons. Like this one: https://tagboardeffects.blogspot.com...hterboard.html

Needs specialised chips.

I like that the chip can also be used in chorus and reverb circuits too.