Open Theremin V3, volume oscillator not working

You can use jumpers with male-female Dupont connectors to separate the Arduino from the theremin board.

It will be sufficient to connect GND, 5V (Vcc), and 3.3V (Vdd).

Thanks all for the help. I'll give it a shot in a few days and report back. Specially the measurement of the capacitors will be a challenge. But I'll see what I can do.

Hello -- I am along the same boat..
The LEDs, calibration sounds all work.. U2 and U3's Pin 7 is 500/460Khz. No problems there.
However, there is no sound coming when I approach it. Also, the Pitch calibration is strange. It seems to go from 0 to 0 Hz. What could be causing this? Many thanks, -t

PITCH CALIBRATION

Arudino Freq: 15977871.00

Pitch Set Frequency: 499992
Frequency tuning range: 0 to 0

VOLUME CALIBRATION

Volume Set Frequency: 460703
Frequency tuning range: 428951 to 487098

DAC value L: 0 Freq L: 31123
DAC value H: 4095 Freq H: -2449

DAC value L: 4095 Freq L: 47038
DAC value H: 3797 Freq H: 100836

DAC value L: 3797 Freq L: 100790
DAC value H: 4355 Freq H: 99178

DAC value L: 4355 Freq L: 99196
DAC value H: -26851 Freq H: 99916

DAC value L: -26851 Freq L: 99870
DAC value H: -23157 Freq H: 99718

DAC value L: -23157 Freq L: 99697
DAC value H: -24580 Freq H: 101204

DAC value L: -24580 Freq L: 101155
DAC value H: 5446 Freq H: 99654

DAC value L: 5446 Freq L: 99666
DAC value H: -10511 Freq H: 99875

DAC value L: -10511 Freq L: 99849
DAC value H: 12697 Freq H: 99263

DAC value L: 12697 Freq L: 99279
DAC value H: 22495 Freq H: 100009

DAC value L: 22495 Freq L: 99984
DAC value H: -9097 Freq H: 100491

DAC value L: -9097 Freq L: 100446
DAC value H: 9550 Freq H: 99688

DAC value L: 9550 Freq L: 99682
DAC value H: -28467 Freq H: 99188

DAC value L: -28467 Freq L: 99185
DAC value H: 13946 Freq H: 99882

DAC value L: 13946 Freq L: 99834
DAC value H: -16493 Freq H: 101052

DAC value L: -16493 Freq L: 101015
DAC value H: 31225 Freq H: 100186

DAC value L: 31225 Freq L: 100194
DAC value H: -24957 Freq H: 100763

DAC value L: -24957 Freq L: 100737
DAC value H: 22500 Freq H: 99957

DAC value L: 22500 Freq L: 99971
DAC value H: -563 Freq H: 100651

DAC value L: -563 Freq L: 100613
DAC value H: -19410 Freq H: 99555

DAC value L: -19410 Freq L: 99596
DAC value H: -23390 Freq H: 99648

DAC value L: -23390 Freq L: 99625
DAC value H: 1338 Freq H: 99725

DAC value L: 1338 Freq L: 99697
DAC value H: 6468 Freq H: 100173

DAC value L: 6468 Freq L: 100137
DAC value H: -24551 Freq H: 99106

DAC value L: -24551 Freq L: 99118
DAC value H: -20108 Freq H: 99315

DAC value L: -20108 Freq L: 99289
DAC value H: -31764 Freq H: 99609

DAC value L: -31764 Freq L: 99568
DAC value H: -7987 Freq H: 99225

DAC value L: -7987 Freq L: 99241
DAC value H: -15315 Freq H: 99645

DAC value L: -15315 Freq L: 99633
DAC value H: 22635 Freq H: 100093

DAC value L: 22635 Freq L: 100064
DAC value H: 30620 Freq H: 99985

DAC value L: 30620 Freq L: 99979
DAC value H: -21382 Freq H: 100515

DAC value L: -21382 Freq L: 100486
DAC value H: -3481 Freq H: 99375

DAC value L: -3481 Freq L: 99383
DAC value H: 24835 Freq H: 99250

DAC value L: 24835 Freq L: 99236
DAC value H: 3517 Freq H: 100706

DAC value L: 3517 Freq L: 100641
DAC value H: 22167 Freq H: 99840

DAC value L: 22167 Freq L: 99851
DAC value H: -12515 Freq H: 100908

DAC value L: -12515 Freq L: 100866
DAC value H: -8792 Freq H: 100614

DAC value L: -8792 Freq L: 100599
DAC value H: -29668 Freq H: 100428

DAC value L: -29668 Freq L: 100405
DAC value H: 30662 Freq H: 99955

DAC value L: 30662 Freq L: 99959
DAC value H: -11594 Freq H: 99419

DAC value L: -11594 Freq L: 99410
DAC value H: -9157 Freq H: 100488

DAC value L: -9157 Freq L: 100431
DAC value H: 25818 Freq H: 99640

DAC value L: 25818 Freq L: 99640
DAC value H: -32470 Freq H: 99234

DAC value L: -32470 Freq L: 99237
DAC value H: -30396 Freq H: 100170

DAC value L: -30396 Freq L: 100123
DAC value H: 9077 Freq H: 99493

DAC value L: 9077 Freq L: 99495
DAC value H: 23499 Freq H: 100434

DAC value L: 23499 Freq L: 100386
DAC value H: -11728 Freq H: 99331

DAC value L: -11728 Freq L: 99350
DAC value H: 16069 Freq H: 100827

DAC value L: 16069 Freq L: 100775
DAC value H: -22163 Freq H: 100109

DAC value L: -22163 Freq L: 100112
DAC value H: -7598 Freq H: 99342

DAC value L: -7598 Freq L: 99336
DAC value H: -29031 Freq H: 100780

DAC value L: -29031 Freq L: 100715
DAC value H: -199 Freq H: 100879

DAC value L: -199 Freq L: 100837
DAC value H: -539 Freq H: 100605

DAC value L: -539 Freq L: 100606
DAC value H: -16905 Freq H: 100618

CALIBRATION COMPLETED

@tkalfaoglu

I think he good news is that your volume calibration is between the bounds. Looks like the capacitors there are working. I expect that he pitch pad currently is incomplete. Have you checked the oscillator?

@tkalfaogluI think he good news is that your volume calibration is between the bounds. Looks like the capacitors there are working. I expect that he pitch pad currently is incomplete. Have you checked the oscillator?

Many thanks - I almost have it working! But the pitch is my problem.. How do I check the oscillator?

Hej Bernd,The DC voltage at U12 Pin 5 and 6, and both pins of R5, R6, L2 should be something about 2 ... 3V.We had similar Problems when I built up this theremin with a student. One problem was that she assembled the wrong capacitor. And as I remember, there was a short circuit directly from the volume antenna to GND of the PCB, because we've used a washer.Remove the volume antenna, screw and washer. Can you now measure a signal at U12 pin 6?It's not easy to measure the capacitance in the circuit. So I would suggest toto remove C8..C12. Double check the capacitors and then assemble only C8,C9 and C10. (Later on, if it works, the others)gerd

Sorry for my noobness but my schematics or parts list does not mention U12. Where do I find the elusive U12?   My issue is the pitch, it doesn't work..

Man... take the schematics and an oscilloscope and move on systematically. The oscillators are simple Colpitts style around a CMOS inverter. No rocket science.

Thierry, you can do better than that.  You can answer his question just about as easily as you can chastise him for not figuring it out himself. Or just ignore his question without comment. 

It's no wonder newcomers take a peek at this forum and go running.

Sheesh...

Thierry, you can do better than that.  You can answer his question just about as easily as you can chastise him for not figuring it out himself. Or just ignore his question without comment.  It's no wonder newcomers take a peek at this forum and go running.Sheesh...

Thank you very much - I am unfortunately not as well versed as Thierry (desole) in electronics, so I am unable to figure out why the pitch is not working.