Another Jaycar Mod

Posted: 4/8/2012 9:30:13 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

I'm also somewhat impatient to hear about the ongoing of the story... 

Posted: 4/10/2012 12:01:23 PM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Well, friends... I guess I'll have to make sound samples without the definitive antennas (will use the original ones and record with opened cabinet)... Can't find someone to turn them tips into p10... I'm not saying that I'm giving up... Just need more time to do it... I'll record the theremin connected straight to my soundcard's microphone jack, and post the results this week... In the future, final pictures will be posted too... 

Posted: 4/11/2012 12:31:10 PM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Recording... Theremin turned on for a longer period of time, I've noticed that tones get (really) higher (I didn't measure it but I guess it should be more than a half octave up in 10 minutes), warming up is common on theremins (at least on my RDS I give 15 minutes of warming up before trying to play)... Is that a common pitch variation for this model while warming up? How long should I wait for Jaycar to warm up?

Posted: 4/12/2012 2:24:52 PM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Uploading video sample... Meanwhile a pic of my mess:

Posted: 4/12/2012 7:04:17 PM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Here is my first sample... I'm recording straight from theremin's output (mono) to soundcard input (stereo), so it's sounding not as loud as I expected, I've used Soundcard Scope 1.4 and CamStudio-Recorder to make the video...

00:00 - 00:18 - Pitch range (hand-antenna, not potentiometer)

00:18 - 00:57 - Waveform potentiometer variation

00:57 - 01:12 - Symetry  potentiometer  variation (wich seems to modify pitch values... I didn't had time to apply Thierry's page 2 adjustments)


http://www.youtube.com/watch?v=c4G--D1kE3Q&feature=youtu.be 


Theremin's cabinet is actualy closed, and I used an ordinary FM radio antenna plugged directly to p10 jack as pitch antenna for primary tests, volume antena isn't conected yet (but working fine)... 

Posted: 4/12/2012 8:29:53 PM
Touchless

From: Tucson, AZ USA

Joined: 2/26/2011

ggj1977

I was pleasantly surprised watching your waveform and the harmonic content in my own software, this is exactly the results one would hope for in an initial sound byte. Sound is one component now how are the other functions?

Job well done!

Posted: 4/12/2012 8:36:14 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

You passed RS Theremin's requirement of recording the audio! ;)

Posted: 4/12/2012 9:27:43 PM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Thanks a lot, Touchless and Dewster... I'm intending to finish it, with definitive antennas and Thierry's adjustments of waveform and symetry (actually I would really apreciate to read his impressions of my results!!) before playing anything for you... I may post a video comparing Jaycar and my RDS with this osciloscope in the future too... 

Posted: 4/17/2012 12:10:11 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Now I'll tell you a secret: I don't care much about waveforms. With a professional playing technique (left hand articulation, right hand fingering for perfect transition between tones, vibrato, etc.) you can influence the sound much more than any synthetic waveform could.

Best example is Dalit Warshaw playing Clara Rockmore's theremin: There is nothing of the brilliance left to which we are used when we hear recordings with Clara playing the same instrument. It sounds rather like a badly adjusted Etherwave. And on the other side, there is a video on youtube where Lydia Kavina plays a Gakken Mini theremin: Very impressive what a professional player can get out of a crappy plastic toy...

In ever case, the perfect "historic" theremin sound which is basically somewhat stringy and buzzy in the lower register and like a singing lady in the high register has not yet been created with whatever transistor theremin - it seems that there is still some magic in vacuum tubes. The tonal transition between the registers should occur between 260Hz and 520Hz like it happens with a female singer when switching between chest voice and head voice. And no oscilloscope or spectrum analyzer will help you with that, only the musical ear of the circuit designer is solicited.

Posted: 4/18/2012 11:41:29 AM
ggj1977

From: Florianópolis, Brazil

Joined: 2/1/2012

Well, Thierry... I don't consider myself a musician, but really enjoy playing this instrument (or trying to do it), the reason of choosing this model is because it is a cheap instrument, with regular pitch field, and it has a built-in speaker, and this will turn my praticing easier so that I could do it more often...

I've posted an osciloscope image because people looked curious about the voice of this theremin, and to have opinions on where it could be improved, since Waveform an Symetry controls don't have the pratical behavior that I was expecting... I realy thought that seeing the waves in a graphic representation of what you can hear was a way to get my answers...

For me, theremins don't have to sound always the same... Actually I find beauty on really low notes (bass)... Smooth or rough, brilliant or buzzy, it's a question of occasion, the way the instrument fits on a particular music as part of it... And it's this versatility that I'm looking for on this particular theremin... As a music novice, theremin practitioner and admirer...

 

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