[Solved] Do I broke my penrose?

Xirso

Hello,

the short version, i have connected the penrose like a dum the first time.

I ask myself if have broken something? Cause when i try to calibrate it, the octave of my oscillator isn't changing when i put some cv source to the cv in of the penrose. And the note range seem's to begin on E and finish on D pushing the buttons on the penrose. When i push on E this button always plays a note he never come green, always directly red, strange(or not?). All the other things, gate out, trig in, work good. Any idea?

papernoise

Hmm, does not sound normal. Did it ever work correctly, or was it like this right from the beginning?

Xirso

It never work correctly. The ribbon cable that i have received had the red strip on the "wrong" side. So when i connect it to the bus board with the red stripe on the bottom i think that the gate from the doepfer bus board was connected to the +12 of the module, the CV to the GND, the +5v to the GND, the +12v to the GND and the GND to the -12. 

I look at the IC position and if a solder joint has a short with another and if the CV in jack solder look like the other, but only with eyes not a multimeter or so (just the continuity test of the build instructions was made with a multimeter), it seem's ok. By chance is the first diy project that i have to debug. I'm asking myself if a multiplexer has fried or has his shift register broken, perhaps it could explain why the first note of the octave seem's to be E and not C. Does the C button of a penrose working good, behave like the other button? Or go only red or off, and directly play if you press it?

julian

in general the penrose is protected agains wrong polarity with a reseting fuse.

- how is your penrose connected to other modules for testing? just something like an LFO/manual CV to CV input and the CV out to an oscillator?
- the LEDs and buttons are working?
- the CV out does not change at all with all buttons active and an incoming CV?

Xirso

Thanks, good to know that the penrose is protected, that's give me hope.

- The penrose receive an LFO to the CV input and the CV out of the penrose goes to an oscillator, like you write.

- The led and buttons are working, i can press every button and turn them red, green or off and that change the cv out value when a button is red. My osc react but the note playing by the osc are always in the same octave. The octave is much higher as the octave from the osc without the penrose connect to it.

- With all buttons active and an incoming CV the CV out does not change (i dont hear the sound of the vco change).

Another question, the trimmer of the penrose must be turned approximatively from 0° to 360° to be at his minimum or maximum value or it need to be turm much more.

julian

the trimmer is a multi turn model. so 0->360° is not the full range.
you will hear a faint 'click' once the trimmer is at its end.

but the trimmer only adjusts a small bit of the CV range. so even if it is set to max/min you should hear changing notes. So this should not be a calibration problem.

since your OSC is reacting to button presses my guess would be that something with the CV input is wrong on the penrose module.

- what output voltage do you measure on the CV out with nothing connected to the CV in?
- Is the red LED moving with all buttons green and an incoming CV from the LFO?
- with a constant CV on the input. for example 5V, what do you measure on pin 23 of the AVR (alternatively pin 1 on the MCPO602.

here is the schematic:
http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf

the CV in signal flow is:

on the top pcb
CV jack -> R15 (100k) -> TL072 (U2B pin 6) -> JP1 connector pin 8

bottom pcb:
JP2 connector pin 8 -> R7 (100k) -> MCP602 pin 2 -> AVR pin 23

Xirso

Thanks,

Your response give me a better understanding of the schematics and how to use them to follow a signal on a pcb.

So, I have put some more solder on CV jack. Use a solder bread between pin 1 and 2 from the MCP602 to prevent a short between the two pins, resolder the pins. And guess what... The penrose react how i was hoping. The red button change corresponding to the value send to the CV in, whith a LFO or an other cv source. And the VCO is playing on more than one octave. All seem's ok. 

Testing the penrose with an LFO to the CV in and the CV out to the pitch of a square wave gives me a sound like pac-man. :-)

Thanks for your help!