D’Lay Build Version Differences

[Cybercow]

I’ve noticed some of the values have changed in the newer D’Lay version. I’m pretty sure I can follow the BOM for the 2021 version of the D’Lay build document to build out the earlier version. I have two D’Lay builds, each a different version. One is version 2 (the green PCB) and the other is version 3 (the white PCB). In any case, I wanted to bring this out in the open and ask just in case. I’ve looked over the schematic on both build docs and the only real difference I can note is the value of C1 between pins #9 & #10 on the PT2399. So while I’m here, I’m asking, hoping Barry can shed some light on the difference between the BOMs and schematics of those two different versions.

I’m concerned about the value of C1 between the two versions. On v2 the value is 220n and on v3 it’s 82n.

Oh, and will the 78L05 (not the 7805) regulator support the weight of both the PT2399 AND the Tap-Tempo optional add-on circuit?

[Barry]

If you look at the schematic on the old version it shows our current values as well.

These are actually the original values.

The 2 changes were to put C1 and C2 back to their originally prescribed values.

Here is the short or long of it:

C1 and C2 forms a low pass filter in order to reduce the unwanted hi-frequencies. Lowering the values of C1 and C2 will allow more high harmonics to go through the chip and therefore a “more natural sound”, of course, the drawback would be more digital noise into the signal.

Using 100nF on C1/C2 makes the delayed signal harmonics above 1kHz to be attenuated, it is not catastrophic as the natural sound of a delayed/echoed signal has intrinsically less high content. A good middle ground value to allow more harmonics and less HF noise into the circuit would be 68nF. 

I no longer feel comfortable going with 220n so hence the change back.You could socket one of those boards for comparison to see what you think.

I have heard of no issues using that regulator for both.

[Cybercow]

Barry – Thanks for all of that. As always your explanations are clear and concise.

To be clear, you’re suggesting I try 68nF in BOTH the C1 & C2 locations? Or just C1? And yes, there will be sockets!  😉

Oh, and here’s an assembled screen shot of the schematic & BOM differences that confused me between the two. (I really should have led with this.)

[Barry]

I do not think you are going to notice much difference between 68n and 100n but most likely 220n.

Additionally the new D’lay values as they are in the BOM would be the original recommended values.

[Cybercow]

Barry – thanks! With the number of mods available, I’m gonna max one out, use trimmers in the mixing and gain section and include PinkJimi’s buffered-tails option. Once done, (it’ll be a while), I’ll show it off in the appropriate forum group.

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