• My programmer is finished now, but failed sound check in a strange way. I’m hoping maybe someone has a suggestion or ran into this before…

    The filter directly connected to the controller board is a digital filter. The second filter is an SMR-4 mk1. The Shruthi is set up for digital filter/programmer. Everything seems to work properly with the SMR-4… All knobs function properly, but I’m not getting any oscillators from the digital filter. I DO get filter resonance self-oscillation and noise from the digital FX, but nothing from the oscillators at all.

    The I/O looks like this: the first 6 analog out pins get sent to both filters (+5V-Q), the digital filter is also getting all six pins from the output expansion and the first 5 pins of the output expansion are going to the programmer along with CVIN-1.

    Looks okay… But I lost my digital board’s oscillators? WTF?

  • I think I somehow smoked my digital filter?

    Tomorrow I take it all apart and test everything with separate equipment. Unless someone has another idea…

  • sad face! Hope not. godspeed

  • Check that you get the oscillators signal on Pin 14 of IC1 on the digital filter board.

  • I seem to have resolved the problem! Something with the wiring I guess. I don’t know why I didn’t solve this yesterday? I know I went over everything I did today? Sometimes you just need to walk away from it for a few hours before it makes sense…

    Now, I need to un dyslexia the LEDs on the switches (doh!) and figure out what I did wrong with my MIDI wiring and I’m done. At least until I receive my cutting tool in the mail and I can carve holes for volume pots.

    Thanks for the help @pichenettes!

  • Done. It works!

    I’m not 100% happy with the way I did it. My goal was to avoid doing anything permanent to the filters so they could be swapped out. But I was overmatched. I thought I could tap the audio somewhere, from the header, from a volume pot, from audio cables plugged into the jacks, but I just couldn’t do it. There wasn’t enough room for jacks and adding something to the board to allow for a plug would have been sillier looking than just soldering audio wires.

    But I was beaten only by the audio. Everything else is connected using a detachable connector.

    There is so little room to work in the case that it was a bit difficult to coax the lid on etc. But I eventually got it. I will take pictures when I crack it open again to add volume pots. They will go on the front (there is no other place for them that I can find) and are really essential on a programmer with two boards. Nothing can compete with the SMR-4 mk1 in terms of volume. So when I get my cutting tool, those knobs are going in and they will be connected using detachable connectors.

    For now, I just want to play…

  • On mine I removed the links where the volume pots can go and fitted pins. I then used connectors to connect from the pins to the sockets.

    You use the outer two pins, one is signal the other is ground.

    On the SMR4 (mk1, not sure about mk2) the spacing is wide but on the Polivoks you can use three pins in a row.

  • @6851punk – I have already installed pins/headers as you have suggested. Were you able to tap the audio signal from there rather than use the pins at the sockets? If so, can you describe it in a little more detail please? I found I needed the T/S pins or I got a very weird distorted sound… maybe I did something wrong?

    Edit: Digital board has 2.54mm spacing between pins, SMR-4 mk1 has wide spacing. It’s the two outer pins will fit a 4-pin connector, but the middle pin is sort of in the middle and requires some fancy workaround stuff if you want to fit it into a standard plug.

    Here is a little demo/test of my programmer. Not doing much, just a sequence and some drums. Sounds killer though if you ask me. Pure Mutable Instruments…

  • If you look at the picture of the filter board you’ll see that the audio goes to the bottom pin of the three and the top pin is ground.

    So you connect the bottom pin to the tip of the socket and the top pin to ground.

  • I could not make that work. I did just as you said. I wish I knew what I was doing wrong?

    I actually had alligator-clip jumpers connected from the header pins to the audio output jack. Got nothing but hum no matter what I did. Then it occurred to me that maybe it needs to be shorted first so, since I intend to install volume pots which does the same thing – I hooked up a pot, all with alligator jumpers and I got audio but it was poor quality. It sounded decent on one end of the pot sweep and then, towards the end of the other side of the sweep, the audio got distorted and sort of dropped out. It was repeatable and with other pots.

    That’s when I gave up and soldered the wires.

    If you are doing it, I must have made a mistake somewhere. I will try it again when I pop the cover to install the pots.