I built a Multiplex Jr. Delay from Josh over at 1776 Effects and I am trying to add Tap Tempo using the Taptation chipset & microcontroller from the Tonegod on the TapTempo Board from Barry at GuitarPCB (see build docs)
Multiplex Jr.:
file:///C:/Users/funkman49/Documents/Footpedals/Effects%20Layouts%20Schems/Current%20TJ%20pedal%20schems/Delay%20&%20Reverb%20Effects/Stutter-Step%20Schems/Multiplex-Jr-BOM.pdfTapTempo v2:
file:///C:/Users/funkman49/Documents/Footpedals/Effects%20Layouts%20Schems/Current%20TJ%20pedal%20schems/Delay%20&%20Reverb%20Effects/Stutter-Step%20Schems/TapTempo_v2_Build_Doc.pdfAfter verifying that the Multiplex Jr. circuit is working properly and measuring proper voltage on the Tap Tempo board as well as functioning Tempo Scale LED, working momentary footswitch, double time switch, and tempo scale switch. I proceeded to connect the Multiplex Jr. to theTap Tempo board.
All Tap Tempo functions are working properly, however I cannot get the Delay to respond correctly or sound like a delay.
I tapped into the MP Jr. at pad 3 for the Time pot and connected the other end of that wire to the PT6 pad of the Tap Tempo board as is suggested in build docs for the GuitarPCB D'Lay.
With the 2.7K R25 resistor in place I get no delay effect except for some mild & occasional popping sounds. Changing R25 to 2.2, 2, 1.8, 1K (this value is used on the D'Lay board), as well as inserting a jumper I go from louder popping to increasingly weird blips, bleeps, and bloops.
Also...
I am not using the Modulation from the TapTempo v2. I prefer the sound of the Macron optocoupler and the ability to use the Depth control for the Modulation which is supplied on the Multiplex Jr. board so I have omitted R4 & Q2 on the Tap Tempo board. There is no connection from the pin 6 of the Tapflo chipset to pin 7 of the digital potentiometer.
See gutshot:

Could my tap-in point on the Multiplex Jr. be the problem?
and/or could my use of the modulation on the Multiplex and not the modulation circuit on the TapTempo board also be a contributing factor?
Any insight or advice would be greatly appreciated!