Identifying a strange fault in one of the penny organ's digitally controlled oscillators.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
Good morning all…
Youtuber, shed dweller, solar charge controller aficionado
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It's not apparent from what I can see in the video whether there are any power supply bypass capacitors in there, If I were building something like this I would have at least 100nF on each of the oscillator modules and also some smaller caps (100-470pF?) on the signal outputs. If you look at a schematic of a lot of electronic musical instruments you find that there are bypass caps all over the place. Needed, I think.
Where are the sharps/flats?! 🙂
you clearly play, may ask what sir ?
Put in an option for a triangle wave.
Good one again! I guess the continuous offset on the outputs will probably give you some headache later in the vocoder. So I really suggest to add a bipolar electrolytic capacitor in series of each output to the summing point, or later to the inputs of the vocoder. For the noisy module, check for a broken chip capacitor. May be just put a normal legged one across some of them to check which one is broken.
I can see this as a foundation on which to build a (simple) OCR/music player. Add one more digital oscillator, and replace the 8 coins with 8 reflective-mode opto-couplers, a stepper motor, and some specially prepared "sheet music", and the four buttons on the left as stop/start, rec/play, FF and rewind. Make a simple conveyer belt driven by the stepper motor to pull the strip of sheet music under the reader head (the opto-couplers), and have the arduino read them and send the info to a PC, or to internal memory, while playing the notes as you already have. Voila – Arduino-controlled player piano! 🙂
I'm thinking you are going to need 5 more coins … You've got the 8 White keys (one of which is an octave). The Black keys (in 'flats') will be B, E, A, D and G. I must say, you've got a good ear!!
I am just guessing, but this "distortion" looks like typical symptom of too low capacitance (or resistance) on PWM output. If these chips indeed have PWM outputs then check the output cap.
aye old sqauff
time to rob the Norwegian bank again for more Kroners with holes 🙂
Hello, verry amazing 🙂 is-it possible to have the references for where to buy the vco ?
well I could hear the attack click… but the different DCOs all sounded just the same to me 🙁 guess I'm not very musical
Thanks Julian, good one.
Can you share the code somewhere?