Volume only theremin schematic

Posted: 12/27/2017 8:30:21 PM
PhoneticsQ1

Joined: 12/27/2017

Hello all! first post here. 

 

I'm interested in building a volume only unit, basically something along the lines of Theremaniac's Volume Control Unit 

To do this must you:

- build the volume processor section of a theremin circuit 

- the volume oscillator + processor

- or the vol oscillator + processor + amplifier circuit?

Does anyone have any schematics they would recommend following? 

Posted: 12/28/2017 12:38:31 AM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

Hey Phone...home,

This is an area that has always fascinated me with little coverage. A quality volume control is more complex than the pitch side with the sound of Clara. I doubt anyone is out there other than me that has anything to offer. I broke my brain a while back and rather be drunk now than do anymore theremin stuff, dew is not far behind. I do have an approach I will share along with a circuit board and exotic parts at no cost to you if you are in the states? I have lots of stuff to get rid of before I check out and it all goes into a dumpster.

Here is my touchless sample at work Sound Sample

Chuck Collins at Theremanic I always admired, think I remember his name correctly. He told me his volume approach was extremely simple. That is a clue for the technical minded, maybe a floating gate on a jfet?

What special feature are you hoping to find if Chuck's volume is not adequate? If you do not need a touchless approach just the smooth effect on the sound I have a very simple method, a little imagination could do more with it.

Christopher

Posted: 12/28/2017 1:39:23 AM
PhoneticsQ1

Joined: 12/27/2017

Thanks for the reply! I am on the east coast.

The theremaniac volume approach is exactly what i want, i would just like to try to construct one myself! Yes, a photocell approach has occurred to me, and I have experimented with them before. but the point is for this to be theremin-based/touchless.

 Your touchless sample sounds good! What is your approach?

Posted: 12/28/2017 1:53:55 AM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

Phone said "The theremaniac volume approach is exactly what i want"

First are you buried under snow?

My touchless approach is way too complicated if Chucks approach is good enough.

A volume control can be on to off, or creatively expand on this response like the size of the control window, etc.

Christopher

Posted: 12/28/2017 2:14:02 AM
PhoneticsQ1

Joined: 12/27/2017

no snow.

well, i have not heard any sound samples of theremaniac's volume control unit, but from photos it appears to be what i would like. but i do not have the money to purchase one, and would also prefer to try to build one regardless

Posted: 12/28/2017 2:33:10 AM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

PhoneticsQ1, if it will be just you playing it and not a classically trained Thereminist, I'd recommend you go for a nearer = louder response.  I pretty much loathed the standard Theremin volume axis until I configured mine to respond that way (IMO, YMMV).  Flipping a switch or twisting a knob to get the opposite response would probably be ideal as then anyone would feel at home on it, but to me it is insanely counter-intuitive the standard way.  You push your right hand at the pitch antenna to get "more" frequency, I have to split my brain in half to then get "more" volume by pulling away from the volume antenna.  Attack is easier too if nearer = louder as stronger muscles and gravity are assisting.

The standard volume side is stimulating the series L & antenna / hand C with a fixed tank LC, both tuned almost the same, then "detecting" in an AM sense the resonance amplitude.  The signal can be quite large for quite small frequency differences (the phase difference is magnified by the LC Q).  A way to detect the large phase difference directly would be with an XOR gate or similar (then filter the ~PWM, or maybe use it directly as PWM?).

Posted: 12/28/2017 7:16:50 PM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

Phone, here is my schematic for how I do my analog pulse width modulation volume control using the changing rf waveshape. It may give you some ideas as there are many ways to do the same thing or get similar results. I have never seen anyone post a volume schematic in my 15 years of theremin research as a stand alone, it can be more complex than the pitch side that has the beautiful sound of clara. Most people are happy with a cheap digital whistle or an unnatural sound. I believe digital is the death of the natural theremin.

I am no longer able to assist people with troubleshooting my own stuff. Maybe someone will share a simpler digital schematic.

If you want cost effective buy the Theremaniac.

Christopher

Edit: My design evolved by only using parts purchased at Radio Shack. Ths made it challenging and fun for other builders.

Posted: 12/28/2017 8:39:15 PM
BBrinkman

Joined: 11/20/2010

"Phone, here is my schematic for how I do my analog pulse width modulation volume control using the changing rf waveshape. It may give you some ideas as there are many ways to do the same thing or get similar results."

 I like this Christopher. For the last couple months that I have spent assembling my Etherwave Plus I have been contemplating further projects, one of which was using the CV Volume out to modulate the output voltage of a high-voltage SMPS. 

Posted: 12/28/2017 9:44:20 PM
PhoneticsQ1

Joined: 12/27/2017

Thank you for the reply, Dewster, and thanks for the schem, Christopher!

Posted: 12/28/2017 10:32:13 PM
oldtemecula

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

Hello BB & Phone,

I used my version of PWM from the start because I didn't know better. I was learning electronics as I went along. Here is my webpage for an add-on to my PWM volume control. I wanted the volume to control the mood by dimming an LED flood light on the artist while playing. Full volume was brightness, quiet volume gently dimmed, no sound the light is off.

Those were fun times, never met anyone locally I could have explored my creative ideas with. I have 100's of theremin webpages that I showed builders how I did things. I am not an engineer so was able to think outside the box, plus always demonstrated my ideas because they worked. I could no longer help builders troubleshoot due to the cellphone becoming the main tool for communication. Conversation became to cryptic.

Even to this day I have never owned any type cell phone, I am old now, stubborn and cannot change. Like the theremin I will remain in the past.

Now at the twilight of my theremin research, I still hope someone else's creativity might be sparked by something I did.

Christopher

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