basic experiments

Posted: 2/19/2020 4:20:11 AM
innominata

Joined: 2/9/2020

Even after reading all this content on the output of the mixer waveform and the harmonics that determine the timbre of an instrument I can't figure out what the intermediate steps are.

If you need harmonics for good sound naively the first question that arises to me is "how do you introduce harmonics?"

Is this the correct question to be asking?

Posted: 2/19/2020 7:45:37 AM
innominata

Joined: 2/9/2020

It just occurred to me that different types of mixers will create differently shaped envelopes.

If I had read the whole thread at first I would have realized, this was in the earlier sections. Ignore my question!

Posted: 2/20/2020 9:06:26 PM
JPascal

From: Berlin Germany

Joined: 4/27/2016

I had a bit spare time far away from home, but was also thinking over the theremin adsr. Now I am optimistic to find a solution. But it is indeed not trivial. 

First result to show the progress in cracking the nut. The green line is for input the voltage controlled amplifier while the red one follows the output of a common volume control. 

 

Posted: 3/3/2020 10:25:09 PM
JPascal

From: Berlin Germany

Joined: 4/27/2016

A first test. Only the velocity of volume hand moving is varied. The attack period can be shortened to less than 10 milliseconds. This is the new effect I was looking for compared to a conventional volume control.

Posted: 3/16/2020 9:51:02 PM
JPascal

From: Berlin Germany

Joined: 4/27/2016

Now I've made a short video of the ongoing work on the volume control response unit.

Posted: 3/17/2020 2:21:12 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

JPascal, quite interesting!  It seems the "velocity" sense of your circuit is opposite that of Dominik's?  That is, a quick stab towards your volume antenna causes an attack type envelope?  If so, it seems like it might interfere with the way most players play, as they usually use quick stabs at the antenna between notes to shape them (i.e. to give lower volume between notes).

Posted: 3/17/2020 5:54:17 PM
DOMINIK

From: germany, kiel

Joined: 5/10/2007

JPascal, nice! After 100 years the theremin gets 'velocity' or how you describe it a 'volume attack accelerator' (decay also?). From only our videos theremin players maybe don't get a clue what it's all about and may see it as a weird effect nobody really needs. Fortunately i know from at least a few of my customers that they don't want to miss it. It'd like to bring to mind that this feature greatly helps to overcome the theremins slowness in a natural way. It simply follows the players intention – be it staccato or smooth crescendo or anything in between.

Dewster, to me it looks familiar (quickly away from the antenna = faster attack). Could it be that there has been a picture/sound delay with your compi or whatever?

Posted: 3/17/2020 6:35:02 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

"Dewster, to me it looks familiar (quickly away from the antenna = faster attack). Could it be that there has been a picture/sound delay with your compi or whatever?"  - DOMINIK

Ah, you're right.  For some reason watching it embedded here at TW it seems a bit delayed and therefore reversed, whereas over at YT it looks like it behaves very much like your Subscope velocity.  Thanks for suggesting that possibility!

JPascal, is the bulb there to test for AC mains pickup?  I'm interested as to how that might be reduced in an analog Theremin.

Posted: 3/17/2020 10:44:00 PM
JPascal

From: Berlin Germany

Joined: 4/27/2016

Dominik, "velocity" or "volume acceleration" should be supported as a new standard. Your costumers and also first reactions of professional players on my video indicates this. You are the spiritus rector. 

I was very curious, how that is possible, and invested a lot of time to think about and to find a key. In my opinion, the ability to do such natural volume dynamics is as important as the right pitch skills. After 100 years, yeah!

Dewster, the bulb produces no flickering, but I can test the influence on/off next time. 

Posted: 3/21/2020 10:17:18 AM
JPascal

From: Berlin Germany

Joined: 4/27/2016

Maybe it is a recommendation for other developers and experimentators. To avoid unspecific coupling effects within the moduls I used 3 separate batteries for the volume, pitch and vca unit. Mass is connected. Breadboard tests can this way rather be succesfully. In the end version this will of course not be neccessary.

 

Dominiks commercial velocity solution and my experimental study show compared to other theremins a decisive difference due to the new performance options. Short volume exaggerating attacks below 30 msec or ordinary crescendo/decrescendo effects are possible, without any knob changes practically possible at the same time.  In this record the white vertical strip is a time period of 30 msec.

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