B3 Deluxe--- stand question.

Posted: 10/13/2009 3:41:41 PM
Orwell84

From: Chicago

Joined: 10/10/2009

Just got my first theremin in the mail, a B3 Deluxe. It has a recessed slot for a mic-stand, however, I bought a mic-stand from Guitar Center and it is extremely loose in the slot its supposed to fit in to. ALSO, when I put the theremin on this ill-fitted stand, it made the sounds of the theremin completely reverse (the closer I got to the antennae the lower the note). Any suggestions from any B3 players?
Posted: 10/13/2009 4:36:58 PM
GordonC

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Hi Orwell84, welcome to Theremin World. :-)

I'm not a B3 owner - I expect there will be an expert along presently, but in the meantime some observations.

Firstly Dan Burns has something of a reputation around here for being helpful, so if we can't help probably he can.

OK, the wobbly fitting - is the slot threaded? Without seeing it, it is possible you got a slim fitting on your mike stand? In which case an adaptor would be in order.

Second, the pitch field. It is possible that while it appears reversed, it is in fact dramatically shrunk. To explain, in normal operation the notes start high near the pitch rod, and get lower until the oscillators lock and you enter the zero-beat area, which is silent. Further beyond that the pitch starts to rise very slowly. The thereminist typically stands so that that part of the field is behind him or her, and little consideration is given to it. (It is also the reason that people walking within a few yards of the theremin will noticeably affect a performance. BTW This is a musician's explanation - the electricians' explanation may differ.)

If the field is shrunk dramatically, there may well be a tiny area close to the pitch rod where it does get higher. What happens when you touch the rod? Does it go high-pitched?

IF this is the case, it MAY be possible to affect a temporary fix by placing a CD on the top of the case, near the pitch rod. Certainly this increases the field size very effectively on my etherwave and my Enkelaar theremins.

In the long run, it is likely that if turning the pitch knob on theremin does not bring the pitch field to a usable size an internal adjustment is required, and for that I defer to someone who knows what they are talking about.
Posted: 10/13/2009 4:38:53 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

Hi. First, you need to (if the stand has one), remove the threaded washer like device from the top of the stand. This is normally a stop for microphone mounts, to keep them from going on too tight. This should allow the theremin to slip all the way down onto the stand. However, some models of stands still have machined lip at the bottom of the threaded portion of the stand. If this is the case, take the stand back and check for a model that does not have that. You want one that, when the threaded washer is removed, is prettymuch smooth all the way down, other than the threaded bit.

Once you have the theremin mounted, retune by turning the pitch knob counter clockwise to bring the field back out to a propper width.

If you're still having trouble, let me, or Dan know.
Posted: 10/13/2009 4:40:13 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

Hi Gordon, B3s don't use threaded holes. :)
Posted: 10/13/2009 4:46:17 PM
GordonC

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Hi Thomas. :-)

That's cool. I guess the B3 is a pretty light piece of kit, compared to the etherwave. (My Kees is featherweight.)

If so then occurs to me that it would look good on a matching wooden stand - if you can find a broom handle the right diameter that's half the job done! Cut to length, fix to a base and varnish it up.
Posted: 10/13/2009 5:15:12 PM
Orwell84

From: Chicago

Joined: 10/10/2009

Thanks much you guys. I gotta try n' find a better stand...the B3 isn't threaded and the stands I've been finding have a ton of extra loose space, so the theremin just wobbles around. Sigh. Must keep looking. Dumb questions but are the tri-pod stands or the straight stands preferred?

Also, Mr. Grillo...thank you so much for making youtube vids. VERY helpful for me and getting started in the right direction.
Posted: 10/13/2009 6:28:05 PM
GordonC

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

I prefer a weighted stand. I think they look so much better.

I also have a tripod because it is lighter and more convenient for carrying around.
Posted: 10/14/2009 4:35:45 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

Orwell84, you're welcome. I have a wighted stand which is fine for etherwaves, but not for the B3s. The other kinds work best. Gordon, I like your suggestion for the broom handle as an attractive stand. :)
Posted: 10/14/2009 4:44:34 PM
Orwell84

From: Chicago

Joined: 10/10/2009

I could be totally off base, but I was assuming the "reversed" tones I was experiencing was due to the metal on the mic stand. It happened again when I was playing near a metal coffee table. Does metal cause that much interference when in close proximity?

Also- thanks for the broom recommendation. I think I might actually build my own stand out of wood. It would be a fun winter project.
Posted: 10/14/2009 5:16:13 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Yes, any metal in proximity adds capacitance and will thus modify the pitch field. (That's the principle of operation of any theremin...) The pitch tuning knob should allow you to compensate these effects. If its range is not sufficient, there is another tuning pot for coarse adjusting accessible via a hole on the bottom.

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