Using Theremin near tube equipment::any danger?

OK. Nice review and explaination on Wikepedia! I personally don't see a problem, but ask more knowledgable folk. While some frequencies may be generated by a vacuum tube in operation, I can't see these affecting the theremin since they would not be grounded to the unit, as the performer would be. This, BTW, looks really interesting!

I am more concerned of a Theremin field being picked up by tube electronics.

Although I can't prove a direct correlation, I've worked with a musician whose old tube SVT bass head went nuts when we had an artist bring her Theremin onstage at a festival. The unit was fine for the whole festival run, before and after her set, just acted up the one time. I just attributed it to the bass head being within a few feet of the therimin. If it's a problem just move it further, the field shouldn't be too large to be an issue most of the time

Not a clue but at 0 to 6000 hz it could if you get it too close. If you have shielding around your tubes/gear though you should be safe. Just move it away if there's a problem. I really just wanted to post some songs that supposedly use Therimin or its cousin the Tannerin. The "Good Vibrations" song used a Tannerin.

Track Listing:

"Good Vibrations" - The Beach Boys
"Shot Shot" - Gomez
"Guitar" - Cake
"Odalisque" - The Decemberists
"We're Not Right" - David Gray
"Holes" - Mercury Rev
"Mental" - Eels
"Cup Of Coffee" - Garbage
"All The Way Up To Heaven" - Guster
"Steel Guitar" - Fred Eaglesmith
"Jacky Cane" - Hooverphonic
"I'm So Small" - Fleming & John
"Bedspring Kiss" - Jellyfish
"Find The Key" - Chineseburn
"Follow My Way" - Chris Cornell
"Velouria" - The Pixies
"Whole Lotta Love" - Dread Zeppelin
"Inevitable Fast Access" - Add N To X
"Green" - Action Figure Party
"Detroit, 1972" - Character
"Hello From Inside A Shell (Zombies Enter The Harbor)" - Of Montreal
"Saturn III" - Fu Manchu
"Malaria" - L.A. Guns
"Jimmy Was A Stimulator" - Scott Weiland
"Better Version" - Shinedown
"Funeral Song" - Sleater-Kinney
"4 Out Of 5" - Soul Coughing
"Space Child" - Spirit
"Wonderboy" - Tenacious D
"Edison's Medicine" - Tesla
"Little People" - The White Stripes
"Echoes" - Pink Floyd

Also sounds like Portishead uses one on some of there music but keyboards can make some of the sounds also.

Have fun.

No worries- tube equipment will be fine with it. Have fun!!