Theremax Electronic Problems`

Posted: 12/3/2005 5:03:38 PM

Joined: 11/2/2005

Well, I got the new coils and tried them out. No difference.

So, I have moved off the breadboard and constructed the Theremax properly. It works like a charm. I wish I knew why it didn't want to work in the breadboard.

Anyway, I can solder in leads to the breadboard to tap into various parts of the Theremax. That alows me to do 95% of my experiments on the breadboard (and gives me much more room now that the theremin is off of it).

Thanks for everyones responses. I will probably through a few pages on line next week detailing my experiments and their successes.

Posted: 12/3/2005 6:16:58 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Hello Ted,

“So, I have moved off the breadboard and constructed the Theremax properly. It works like a charm. I wish I knew why it didn't want to work in the breadboard.”

You are on the theremin journey of trial by fire. It is wise to construct the high frequency oscillator sections on an etched pc board and solder. If the breadboard you are using is the white plug-in experimenter proto-board then the inter-electrode spacing “can” cause problems due to the approximate 5pf capacitance between them. RF energy does funny and unexpected things especially around long test leads.

The rest of the components after the detector should function properly on the proto-board. I have always said that a theremin has more reasons not to work properly or sound good than most would realize. Keep up your nice progress.

The Lev antenna works exactly as I describe at 850 khz and you have the skill to tune it to the Theremax 750 khz and validate the claim of three octaves with perfect note spacing. The first time I saw it happen, to say it was startling is an understatement.

Posted: 12/3/2005 10:34:50 PM

From: Kansas City, Mo.

Joined: 8/23/2005

Christopher, good to see your post... thought you had disappeared...

I really like the tone of the Theremax however the pitch antenna's lack of linearity and it's sensitivity up-down motion make it difficult to play. To hit the notes at the right distance from the antenna is tough enough -- that the up/down motion has hair-trigger sensitivity makes it doubly hard to play in tune.

I have looked over the Lev antenna and would like to try it. How long do you think it would take to build/install/calibrate it?

To balance practice time and hardware/software time is a constant challenge. (Last weekend my ML9600's hard drive crashed so had to replace it and the OS, etc.) Such is the routine of electronic musicians, it seems.

The tone of the Theremax is unique and I really wish it was more playable out of the box... to build a Theremin is a great experience however a time-consuming one.

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