This digital build is meant as a companion piece to an upcoming delay build. The graphics here hint pretty significantly at what the other one is going to be.
This is my 5th delay project, and every single one was a circuit based on the PT2399. This is no exception.
What we have here is a Cave Dweller delay by Madbean. I've put in an "insert jack" to tap into the repeats, either to take them as a wet signal only, or to run them through another pedal and then back into the pedal. I've also incorporated the use of the Taptation PCB by JMK (no modulation) to provide some tappable tempo using the round-topped momentary footswtich. The Taptation tracks pretty respectably for a home-build, though if I were a company making such units to sell, I would probably suggest some sort of tweak to match the tap chipset to any particular batch of PT2399s. I'm very happy with this build and it sounds awesome.
What we have here is a Cave Dweller delay by Madbean. I've put in an "insert jack" to tap into the repeats, either to take them as a wet signal only, or to run them through another pedal and then back into the pedal. I've also incorporated the use of the Taptation PCB by JMK (no modulation) to provide some tappable tempo using the round-topped momentary footswtich. The Taptation tracks pretty respectably for a home-build, though if I were a company making such units to sell, I would probably suggest some sort of tweak to match the tap chipset to any particular batch of PT2399s. I'm very happy with this build and it sounds awesome.
What a mess. Don't judge me.
Originally, this unitl was intended to house a clone of the Deep Blue Delay by Mad Professor, which is a pretty righteous analog-voiced digital delay. That build went great and fired up first shot. However, when I screwed the back plate onto the case, things started to get shifty. I could never quite figure out what the problem was exactly, so I took it out and added the Cave Dweller which I had populated but could never figure out what I wanted to do with. I had considered it as a switchable add-on within another build, perhaps.
In swapping delay circuits, I inherently swapped the PT2399 that was connected to the Taptation. These 2 chips were part of different orders, and are probably from different factories. The chip that's in the Cave Dweller is a much better match for the Taptation as it's configured now. I'd say the tracking went from 75% to 85% just by virtue of the better match.
(A note on the Taptation):
The Taptation is a pretty reasonable hack for the PT2399, but it's achilles' heel is the reliance on a digital pot that lies between the logic section and the PT2399. You can tap in your tempo and switch between all your subdivisions via the toggle switches, and that particular speed will be associated with a value that is then entered into the digital pot, which emulates changing the postition on what would otherwise be a regular pot. This changes the time between delay repeats. However, not all PT2399s are created equally. They can respond to changes in resistance in slightly different ways, which can make a big difference when you're talking about delay repeats that are measured in milliseconds. All things considered, the guys that made the Taptation did a great job considering the obstacles, and it could probably be implemented commercially given the right calibration procedures, but for now it's not perfect. Good enough, but not perfect.
In swapping delay circuits, I inherently swapped the PT2399 that was connected to the Taptation. These 2 chips were part of different orders, and are probably from different factories. The chip that's in the Cave Dweller is a much better match for the Taptation as it's configured now. I'd say the tracking went from 75% to 85% just by virtue of the better match.
(A note on the Taptation):
The Taptation is a pretty reasonable hack for the PT2399, but it's achilles' heel is the reliance on a digital pot that lies between the logic section and the PT2399. You can tap in your tempo and switch between all your subdivisions via the toggle switches, and that particular speed will be associated with a value that is then entered into the digital pot, which emulates changing the postition on what would otherwise be a regular pot. This changes the time between delay repeats. However, not all PT2399s are created equally. They can respond to changes in resistance in slightly different ways, which can make a big difference when you're talking about delay repeats that are measured in milliseconds. All things considered, the guys that made the Taptation did a great job considering the obstacles, and it could probably be implemented commercially given the right calibration procedures, but for now it's not perfect. Good enough, but not perfect.
