New theremin? Nano from Poland...

Nooooooooo. No croissants here. Honest. <Surreptitiously wipes crumbs off lip.> 

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The volume sensor is marked "Timbre" and "Pitch" - I wonder what this means?

"The volume sensor is marked "Timbre" and "Pitch" - I wonder what this means?" - GordonC

Not sure its the "volume sensor" that has these markings..  I think perhaps they are trimmers for the theremin.

I strongly suspect the configuration is as follows:

1.) Floor box has regulators (PSU), Reference oscillator (with tuning knob for this and possibly an accessible "gross" tuning control ("pitch"), Mixer, any/all audio circuitry (including VCA / VCA's).. Any audio adjustment trimmers ("Timbre") would be here. Audio outputs and seperate pre-VCA output "pitch spy".

2.) The volume sensor is a resistive pad (FSR,QTC or similar, as discussed in the Staccato Pedal thread) which is permanently wired to the VCA/s.

3.) Active pitch antenna which is fed DC supply voltage, has a un-tunable (other than by adjusting antenna length)  Variable oscillator, and feeds HF back to 1.

4.) Optional Volume rod, which is fed DC supply voltage, has a tunable oscillator and has detector / filter, and the output of which (Volume CV) is fed via an on/off switch on the rod to a CV summing node on VCA/s in 1.

Fred.

"I think perhaps they are trimmers for the theremin."  - FredM

My feeling as well.

"2.) The volume sensor is a resistive pad (FSR,QTC or similar, as discussed in the Staccato Pedal thread) which is permanently wired to the VCA/s."

I concur.  The pad likely isn't capacitive in nature.  I wonder how responsive it is?

"3.) Active volume antenna which is fed DC supply voltage, has a un-tunable (other than by adjusting antenna length)  Variable oscillator, and feeds HF back to 1."

I think you meant "pitch" antenna.

"Yeah.. it looks like some kind of exposed T-Nut .. IMO that bits not pretty! ;-)"

It's clearer on the volume unit:

Those prongs can be really sharp!

One thing about floor units, particularly "stomp box" thingies like the controller here: the knobs and stuff can get inadvertently stomped on.  I wonder if that "tune" control is up to the abuse?

This is a clever Theremin, obviously designed with an eye towards form, flexibility, and integration.

"I think you meant "pitch" antenna" - Dewster

Thanks! Has been corrected.

"I concur.  The pad likely isn't capacitive in nature. "

Not a guess - that its a pressure pad is stated somewhere on the site.

"those prongs can be really sharp!"

They can be! - I used a load of those T-Nuts on my H1's, both the way they are intended and on the antenna - but after I had snapped the points off and ground them smooth you would never have known they were T-Nuts. I have now found hexagonal threaded couplers with the right OD and ID - more expensive but much neater.

That T-Nut bodge is horrible, could easily hurt someone, could easily be made better, and isnt excusable!

"Neat" certainly doesn't apply to everything about the build!

Fred.

"Not a guess - that its a pressure pad is stated somewhere on the site."  - FredM

Doh!  I should RTFM!  ;-)

From the site: "... with volume foot pressure sensor ..."

From my past experience with T-nuts I find my hands recoiling from the imagined pain of encountering them, even in photos.  Those prongs do give it a bit of pizazz though, like tridents or lightning rods or something.  But seeing them on something like this is akin to recognizing the humble origins of a prop in a SF movie.  Perhaps the photos are of a prototype?  Then again, given the necessarily tiny production runs, does any Theremin ever get to a totally polished state?

"I have now found hexagonal threaded couplers with the right OD and ID - more expensive but much neater."  - FredM

Everyone contemplating designing / building a Theremin should run things by you first Fred.  You've seen it all and can save people gobs of time.  I know you've save me gobs of time and I appreciate all the time you put into your detailed replies here!

Aha! The volume sensor is a pressure pad and also probably houses some of the theremin circuitry. That makes sense.

Oh, I emailed assec to make sure he was aware of this thread. :-)

"... I emailed assec to make sure he was aware of this thread. :-)"  - GordonC

Was the email subject something along the lines of: Uh-oh, don't look now but your Theremin is being "reviewed" (i.e. mentally undressed amidst wild speculation) over at TW!

Seriously though, I hope he shows up so we can pick his brain.  In a friendly sort of way.

"You've seen it all.. " - Dewster

LOL ;-) Thanks Dewster, but I seriously doubt that! ;-) ...

"Then again, given the necessarily tiny production runs, does any Theremin ever get to a totally polished state?"

This is the real crunch - If one is looking at a realistic market, one doesn't mess with T-Nuts and hex couplers, you draft the specification and get the part made.. I (realistically more like had) have clients who would spend several thousand pounds on mechanical bits for prototype / proof of concept and these would just be binned - but when its a food mixer or toaster thats going to be made in huge quantities, and they bill their client for development, its ok... If a theremin builder needs something to couple a tube to a mic stand, they cant afford to get 1000 couplers made at say 50p a piece (or one coupler made at £100) so they MUST use / adapt hardware intended for some other function... If they know they will sell 1000 units in a year, and can get the required funds, they can pay for specific parts.

Its only established companies who can engineer specific parts for volume production, or have the ability to get parts made or produce specific mechanical parts in house -

Its real challenging to overcome these problems (can be extremely frustrating trying yo get connectors which fit tubes*) - but it also appeals to the "inner hobbyist" LOL ;-) .. Im sure there are mechanical things I do which would be scorned by a mechanical engineer who knows whats available "off the shelf" (I do wish there was such a person at TW ;-) but in the meantime all us bodgers can do is share our ideas with each other!

"... I emailed assec to make sure he was aware of this thread. :-)"  - GordonC

Thanks Gordon, its probably something I should have done before starting this thread... I just assumed that assec may have thought people would look at the photo albums and not realize that any action on TW is probably more in the forums than anywhere else.

It is I suppose also possible that English is not his main language, that his web page was translated by someone - Going onto a foreign language forum would scare the s*it out of me if I was trying to promote something and answer questions etc.. In such a case I might just be tempted to post photos and hope they were seen..

Fred.

*I have found a reasonably good solution - Tufnol tubes are really strong and light and have great electrical properties, they are also easy to drill / cut / tap.. But the real beauty is that they come in a wide range of standard diameters and thickness, and one can get tubes made to your own specification at quite low cost. Certainly not the cheapest tube by a long way - One is talking about £20/meter for stuff to support pitch / volume antennas (cheaper the more you buy), but they are epoxy laminated paper and/or cotton/fibreglass (different grades) which is easily glued. Also great for coil formers.

Hi everyone
Sorry, but I'm very busy

more technical informations bellow:
http://assec.pl/details.gif
http://assec.pl/pureout.jpg
http://assec.pl/harshout.jpg

mp3 samples (direct from nano theremin output):
http://assec.pl/pureout.mp3
http://assec.pl/harshout.mp3

"http://assec.pl/pureout.mp3"  - assec

Thanks!  I listened to it and thought I heard some non-smooth pitch change, so I pulled it into Audition:

I can see the non-smooth pitch change, particularly on the low end.  Is this a digital design?  The 128k MP3 bit rate is rather low for an audio sample, but I don't believe the low rate itself could be causing the pitch issue.

Also, what do the LEDs do?  My guess is power and mute?