"Flipping" the Etherwave

Posted: 8/6/2009 4:46:56 PM

Joined: 7/30/2009

Ok, as long as we are hacking our Etherwaves this may as well get discussed too.

I play my theremin backward. When I first started playing I didn't, but then one of my musician friends asked me why I was playing a leftie instrument. For we string players the right hand controls volume (plucking and bowing) and the left is on the neck controlling pitch. So I turned it around, for me it was an immediate improvement.

I figure as long as we are discussing mods to the EW I may as well see what can be done about moving the the controls to the "front" from my perspective.

I used to think that this was a trivial idea, but in reading this forum I'm learning that the position of stuff on the inside effects the way the theremin works so I wonder, can I simply turn the circuit board upside, drill new holes and flip the antennas? Or would there be a great deal more to it than that?

(Seems this thread got double posted somehow, sorry bout that.)
Posted: 8/6/2009 5:16:28 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

[i]"I wonder, can I simply turn the circuit board upside, drill new holes and flip the antennas? Or would there be a great deal more to it than that?" -Carricre [/i]

The length of wire connecting to the antennas affects the capacitance, and therefore the tuning.. The placement of these wires affects coupling between them.

The orientation of The PCB affects capacitances between the PCB and the other parts of the Theremin..

In all, it is not absolutely simple to do.. If you swapped antennas, and put longer wires so that the board was left where it is, I THINK you should be able to re-tune the instrument and compensate quite easily for the changed capacitance..

If you ensured that the antenna wires were not close to each other, and not parallel, I dont think the Volume and Pitch antenna coupling would be too extreme.

My prototype Theremin has swappable antennas (you can see a photos of the core, with antennas shown in both positions here (http://www.therasynth.com/html/neon.html)) But I have no problem with this because it is designed to cater for high variable capacitive loading (it auto-calibrates on power up) so I can screen the internal antenna leads and avoid possible coupling between them as a result - If you were to put screened leads on the EW antennas, it simply wouldnt work (the leads add 20pF capacitance).

I feel sure someone here must have done this modification though, and you will probably get better advice on the practicalities of the modification.

Posted: 9/6/2009 3:33:10 PM

From: Canadia

Joined: 9/5/2009

were did you find a Left Handed Theremim? I'm loking for a LEFT HANDED THEREMIN, IM LEFTHANDED SO I NEED ONE TO PLAY
Posted: 9/6/2009 4:19:20 PM

From: Colmar, France

Joined: 12/31/2007

Oh Frederic, please stop misbehaving and spamming around here now! Your question has already been answered in at least two other threads.

The theremin is already not an instrument "for the masses" but rather exotic and a left handed theremin still more. So don't expect to walk into a music instruments shop and see 20 different left-handed theremins for choice. You'll have either to contact the manufacturers directly or buy a kit and modify it yourself. Exclamation point!
Posted: 9/6/2009 6:37:49 PM

From: Canadia

Joined: 9/5/2009

im sorry that idid not understand but i didn't see anyone ansering my posts and thought no one read that part of the forum and trid lookin g for other places people were posting to
Posted: 9/6/2009 11:19:36 PM

From: Toledo, Ohio United States of America

Joined: 2/22/2006

Idiot! BE GONE!
Posted: 9/7/2009 12:16:54 AM

From: Tennessee

Joined: 7/6/2009

You might, (and this is a very small might depending on the length of the leads), be able to modify it by building another cabinet to house it in, and change the front and back face plate locations. This would leave the leads to the both antennae the same distance, BUT you MAY HAVE PROBLEMS with the control wires draped over the printed circuit board and their lengths being changed.

Please note: As I have not modified one at all, DO NOT TAKE MY WORD FOR IT. Ask FredM or Thierry.

There is loads of information on the forums... I know, I have read through them all.. Takes a long time, but it's better to read then to ask a million times.

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