x0x Heart Tuning

I’m struggling a bit to tune my x0x Heart Euro module. I’ve tried a couple of different tuner applications on my Mac (Chromatic Tuner, PitchPerfect), and neither are able to track the oscillator output (from pin 1 of J1) effectively at lower frequencies, making it impossible to tune the module. Does anyone have any suggestions of (preferably Mac) tuner apps, or other recommendations on how I might do this?


do you have the pacemaker installed?

Hi altitude.
Yes, I have the Pacemaker, and all appears to be working. I separated the two boards again, as the Pacemaker manual suggests, running jumper wires to the tuning header on the Pacemaker. I disconnected the ribbon connector between x0x Heart J6 and the Pacemaker board, and connected J6 to a jack socket, then into my XStation, to get the signal into my Mac.

I can hear a good strong signal from the VCO, it’s just that I can’t seem to pick up the frequency of the oscillator at the low note (when sending 1V to the V/Oct input), using my tuner applications.


Please define low note, as anything below 20 Hz will not be resolved by the audio in of the Mac, ergo it won’t be recognized by the tuning app. If you want to go below this point, you should head for a scope with frequency counter.

@nightworxx when sending 1V to the V/Oct input on the x0x Pacemaker, I can’t get a note out of the x0x Heart that’s high enough for my tuner applications to lock onto.

I have a feeling the level of the VCO output may be too high for the input of my XStation, and is distorting. Does this sound likely?


I think I’ve done it, finally. I found a better tuner application.

Having said that, the instructions mention tuning it over an octave (1V to 2V CV), but it seems to lose tracking before it gets to 3V, which isn’t that great. I’m aware the original had a limited range, but I thought I’d be able to get at least 3 octaves in tune. Maybe it still needs tweaking.

I’d be interested to know if anyone else has noticed the same thing.