Theremin B3 150 dollar box BAD Harmonic wolf tones

Posted: 12/29/2019 8:09:37 AM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

I am grossly dissapointed in this box.  I am getting two notes for the price of one ARRRG !!!  Hissy, white noise. I ordered a good Self powered Studio Monitor speakers in hopes that the problem is the cheap computer speaker/amp I am using now.  Man this thing is dirty sounding.  I Posted a youtube video on the problem, someone tell me what they think. Did I get HobNobbed by a Chineese Forgery?  I don't know, plenty of demos on this box that sounded clean. Mine is so bad I don't even want to practice on it. 1 and a half octives is all I get You can see the video for yourself and please reply here.  Or my forum mail which is  sclancy6591-at-gmail.com Video Link:   https://youtu.be/4Juyj1xSU_U

Posted: 12/29/2019 4:04:52 PM
bendra

From: Portland, Oregon

Joined: 2/22/2018

Check your grounding?

Posted: 12/29/2019 4:33:26 PM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

Check your grounding?After lurking through some beginner posts, I realize there are several sins I have in my setup. Thank you sir. I am too close to allot of rf generating monsters, Computer, Wallwarts, A metal top bench doesn't help etc. DRAT, . I just hope I didn't buy a booger box.

Posted: 12/29/2019 5:02:56 PM
pitts8rh

From: Minnesota USA

Joined: 11/27/2015

I listened to your video and even looked at the sound on a spectrum analyzer.  I can hear everything that you describe and although the pitch of the second tone is not readily visible, I can see a lot of junk modulation around the main pitch.

I agree that what you are hearing is crap. I hate to repeat this, but first please double check your setup to make sure you have at least followed the instructions, and then try to confirm that the noise is present with headphones or alternative amplification. If nothing helps there, then try it in another room away from metal and with a minimum of electronic devices that could interfere. 

If you are certain that you have done everything correctly and you have verified that the noise is there no matter how you have it connected or where, and you just bought it, then I would return it and ask for a full refund including shipping, not an exchange.  Take the refund, buy a Moog Etherwave Standard, and don't look back.  Theremins are frustrating to learn and the close proximity of the two antennas on that B3 model just adds to the headache.  Used Etherwaves can sometimes be found in the $200 range and they are of a more standard physical size for learning on, and are capable of being used all the way to professional performance.

Posted: 12/29/2019 5:19:00 PM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

I listened to your video and even looked at the sound on a spectrum analyzer.  I can hear everything that you describe and although the pitch of the second tone is not readily visible, I can see a lot of junk modulation around the main pitch. I agree that what you are hearing is crap. I hate to repeat this, but first please double check your setup to make sure you have at least followed the instructions, and then try to confirm that the noise is present with headphones or alternative amplification. If nothing helps there, then try it in another room away from metal and with a minimum of electronic devices that could interfere.  If you are certain that you have done everything correctly and you have verified that the noise is there no matter how you have it connected or where, and you just bought it, then I would return it and ask for a full refund including shipping, not an exchange.  Take the refund, buy a Moog Etherwave Standard, and don't look back.  Theremins are frustrating to learn and the close proximity of the two antennas on that B3 model just adds to the headache.  Used Etherwaves can sometimes be found in the $200 range and they are of a more standard physical size for learning on, and are capable of being used all the way to professional performance.


Appreciate your response, and as Bendra pointed out, I knew nothing of the "Grounding" problems causing allot of grief. And all that junk on my bench.
I am probably going to get a 500 dollar one with my tax returns and donate this one to the colleges music dept. At the College I work at. But NOT if it's defective. I will post tonight of my results after Making a ground cord to plug into the wall outlet. I almost went with the single pitch only version for I am so used to using a right foot volume pedal after 25 years of playing a pedal steel guitar.


Posted: 12/29/2019 5:23:31 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

I agree with the others, check your grounding, listen through headphones via an analog headphone amp.  If you still hear the problem, send it back and buy something different / better.  Whatever you do, don't look inside that baby! :-)

Posted: 12/29/2019 6:26:39 PM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

I agree with the others, check your grounding, listen through headphones via an analog headphone amp.  If you still hear the problem, send it back and buy something different / better.  Whatever you do, don't look inside that baby! :-)

Thanx for the heads up, I almost took it apart to check the pitch antenna for a cold solder joint or broken one.


Posted: 12/29/2019 10:41:15 PM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

I am grossly disappointed in this box.  I am getting two notes for the price of one ARRRG !!!  Hissy, white noise. I ordered a good Self powered Studio Monitor speakers in hopes that the problem is the cheap computer speaker/amp I am using now.  Man this thing is dirty sounding.  I Posted a youtube video on the problem, someone tell me what they think. Did I get HobNobbed by a Chineese Forgery?  I don't know, plenty of demos on this box that sounded clean. Mine is so bad I don't even want to practice on it. 1 and a half octives is all I get You can see the video for yourself and please reply here.  Or my forum mail which is  sclancy6591-at-gmail.com Video Link:   https://youtu.be/4Juyj1xSU_U

All Fixed. Thanx to the advice from Thereminworld.com forums, pitts8rh, dewster,and bendra,  this Theremin is sounding like it should. Pay attention to environment, and grounding. I don't recommend taking it apart as I did. One slip with the soldering iron and those Cat Whisker diodes are toast !!! I was too lazy and impatient to order a parasitic ring to slip over the 1/4" Guitar plug output washer, so I dived in CAREFULLY !! Knowing how RF works, I was careful as a surgeon not to touch or bend any circuit board wires, and there's a nest of them. Just bend one an 1/8" left or right and the beat frequency tuning will be whacked, there is a pot for tuning that but I wouldn't want to have to use it.
Unplug power supply and ground wire when not using, one thunderstorm and static can follow the ground wire into the box and POOF !!


Posted: 12/30/2019 10:01:28 AM
JPascal

From: Berlin Germany

Joined: 4/27/2016

Indeed there is a better performance now. That 60 Hz and higher cross modulations from home electronic devices are a serious problem. I am not sure if good grounding allone may help because of your body itself is not strong grounded and capacitive  coupled to the pitch antenna. 

A snipped spectrum of your "clean" record shows remaining 60 Hz modulations with round about -20 dB amplitude to the main tone. 

  

Posted: 12/30/2019 12:14:34 PM
SClancy

From: Lebanon Tennessee

Joined: 12/29/2019

Indeed there is a better performance now. That 60 Hz and higher cross modulations from home electronic devices are a serious problem. I am not sure if good grounding allone may help because of your body itself is not strong grounded and capacitive  coupled to the pitch antenna. A snipped spectrum of your "clean" record shows remaining 60 Hz modulations with round about -20 dB amplitude to the main tone.

I may experiment with a LiPo Battery for a pure DC source.The cheap 10 dollar self powered speakers are another usb wallwart hash and trash, As you probably noticed, still in a bad environment all around, When my studio monitor speakers get here [self powered]
I will move to the kitchen. I could here what you where talking about. But the important thing is convenience to be near this Theremin while I am at my computer. It will be on a mic stand away from the bench.

I was happy enough with the way it is for now as to practice when ever the opportunity comes up. Such as a youtuber's musical intro to his video, I just snap it on and play along with what ever pops up on my computer. Especially Theremin users giving lessons over the internet. I am sure this machine will serve it's purpose as a student beginner machine. I look forward to playing well enough to go for the MOOG/Theremin with programmable voices.  Thanks for the graph. I use that software in my reveals as a paranormal investigator.

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