Drolo MDD programming issues

[Jebus]

Hello everyone!

Long time since last post and almost equally long since last finished build. Finally getting back to this great hoppy: just finished building Drolo's Molecular Disruption Device. This is version 1.1 which PCB I bought waaay back. Stock build, but added switch to try out the internal programs on the Spin FV-1. Those work really well and sound surprisingly good.

However the issues started when I tried bunch of external patches. I have downloaded lot of patches online and also created some with SpinCAD. Almost all of the patches I have downloaded or created only output clean signal or no signal at all. For example from this huge library I have tried maybe half already and the only working one is the Improved Octave Up: https://mstratman.github.io/fv1-programs/

I created simple proof-of-concept volume control effect on SpinCAD:

https://imgur.com/a/RlyOaMt

and the code:

Code Select Expand

;------ Input
;------ Pot 0
;------ Volume
RDAX ADCL,1.0000000000
MULX POT0
WRAX REG0,0.0000000000
;------ Output
RDAX REG0,1.0000000000
WRAX DACL,0.0000000000

This works just as expected. However if I do anything else in SpinCad it wont work. For example simple reverb with the same setup:

https://imgur.com/a/xGydq5J

And the code:

Code Select Expand

; ----------------------------
;------ Input
;------ Pot 0
;------ Minimum reverb
RDAX ADCL,0.2500000000
RDA 122,0.325
WRAP 0,-1.0
RDA 426,0.325
WRAP 123,-1.0
RDA 980,0.325
WRAP 427,-1.0
RDA 1903,0.325
WRAP 981,-1.0
WRAX REG0,1.0000000000
RDA 21990,1.0
MULX POT0
RDA 5727,-0.325
WRAP 1904,0.325
WRA 5728,1.99
RDAX REG0,1.0000000000
RDA 12240,1.0
MULX POT0
RDA 16973,-0.325
WRAP 12241,0.325
WRA 16974,1.99
WRAX REG1,0.0000000000
;------ Output
RDAX REG1,1.0000000000
WRAX DACL,0.0000000000


This only outputs dry signal, no reverb. What am I doing wrong? Is there some setting I'm missing or something? The same happens with all other effects I've tried from SpinCad (OD, fuzz, reverb, delay, flanger etc). I'm not yet familiar enough with the code itself to figure if there's some error, but I think SpinCAD has been used for quite some time with lot of folks.. Or could there be something wrong with the FV-1 chip? This version of MDD is pretty much the same as the concept schematic from FV-1 datasheet. Just added dry/wet blend and feedback loop from right channel output to right channel input. I've tried different effect slots and all have the same result.

I'm using SpinCad 1032, newest SpinASM and PicKit 2. Looks like Drolo has removed the build docs from internet, so out of respect to him I'm not sharing it at least on this point. 

Cheers, Kalle

[Jebus]

Figured out that since the internal programs work I should probably try the same programs on the EEPROM as well. Downloaded both reverb patches, but neither works (no output). So its got to be hardware issue. Maybe the octave-effect does not use some portion of the FV-1 that other programs do? I'll try pulling the PCB out of the box, using some more IPA and maybe reflowing the solder joints around the chip to see if any of that helps.

[Jebus]

I reflowed all the other solder joints except the FV-1 and then cleaned the whole PCB with IPA and toothbrush. No change in the functionality unfortunately.

Co-worker of mine has SMD desoldering station, I think next step would be to go visit him and have him take the FV-1 out to see if there's anything underneath it shorting and then re-solder the chip.

[Jebus]

Co-worker of mine has SMD desoldering station, I think next step would be to go visit him and have him take the FV-1 out to see if there's anything underneath it shorting and then re-solder the chip.

This took bit longer than I expected, but I got the pedal back yesterday. Unfortunately the functionality did not change at all. Maybe the chip is just faulty.