Sonic Potions - Penrose Quantizer DIY Kit

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pjbulls
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by pjbulls » Tue Feb 02, 2021 2:12 pm

No, that does not sound right. These capacitors need to match the load capacitance of your crystal, which is usually in the order of 10 - 20 pF (plus some stray trace capacitance) for the 16 - 20 MHz crystals commonly used in these ATMegas. 50 nF will quite possibly not allow the crystal to resonate at all, and putting no capacitors will likely work better than putting in those.

the_laconic
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by the_laconic » Tue Feb 02, 2021 2:17 pm

Thanks, I thought that was suspicious. I'll try sticking in a couple of 20 pF, which I do have around.

the_laconic
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by the_laconic » Sun Feb 07, 2021 9:51 pm

Well, I think I fried it. While I was attempting to calibrate the Penrose, I think a capacitor shorted out against the control board. Like the instructions specifically warned about. Like I thought I took precautions about.

It looks fine until I patch the output, at which point the sound works but is very noisy, and the LED buttons start flickering. Tried to update the firmware but the red light just keeps flashing.

Is the ATMega likely damaged? Need reprogramming? If so, I'm stuck, but if it might be something else, I can dig into it.

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inner_light
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by inner_light » Thu Mar 25, 2021 7:24 am

Just popping by to say I built one of these last night, thanks in no small part to all the info on this thread!
Forgot to solder a few joints but after I discovered those it fired up fine. Calibration wasn't too bad either! Thanks thread!
My panel is black in a fully silver system, so if anyone has a silver and would prefer black then get at me
Thanks, Christian

twigathy
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by twigathy » Fri Apr 02, 2021 10:49 am

Also built one of these today, but I diverged from the instructions a little bit!
  • Put the electrolytic caps on the reverse side of the PCB to avoid the problems with touching the 'upper' PCB. This is fine, but it might not work for you depending on your power cables.
  • Swapped the 2x5 header for a shrouded header
  • Did all the front panel stuff at the same time - jacks, LED, and buttons - in order to be totally confident everything was lined up correctly
Markings on some of the small capacitors was really hard to read, I resorted to phone camera + lots of zoom. I also found that some pads were a real challenge to solder with the solder not 'sticking' to the pads properly and just remaining on the iron. Not sure why exactly, never had this problem before. Should I have cleaned the PCBs or something?

Not had a chance to play with it properly yet, but did get it calibrated with Mordax Data providing known CV (1v, 2v, 3v, 4v...).

TheGuyFromBelow
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Re: Sonic Potions - Penrose Quantizer DIY Kit

Post by TheGuyFromBelow » Sat Apr 10, 2021 10:40 am

Hey Guys,

started the DIY journey and wanted to build a Penrose Quantizer from Sonic Potions.
I finished the soldering, hooked it up. LEDs of the Buttons are working. Power LED doesn't (maybe I fried it).

The Problem: I get a constant 10V output from the module even if nothing is plugged in.

Any hints what I might try? :(

UPDATE:
Problem solved, It's running now. But i have to say, it was one of the harder soldering jobs I did. Somehow the solder didn't stick very well on some pads. If the problematic connections are the ones on the 8pin connecter between the buttons one might better have a thin soldering iron to re-solder the pins there. Or you could remove the the buttons again :hmm: But that's torture i guess. :) Fun little module I have to say. Perfect match for a DFAM!

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