Is this a standard modification of a Moog Etherwave?

I'm hoping someone can tell me more about this Moog Etherwave theremin I found in a local (UK) auction.
As you can hopefully see in the picture, the theremin itself is fixed to the top of a cabinet. The cabinet itself seems very well made (by Moog perhaps?) but the electronics within look homemade. The external amp is at the base of the cabinet, where controls are accessed via a cut-out in the cabinet housing. The instrument only seems to make any sound if a lead is connected from the theremin output jack to the amplifier input jack - there is a lot of hum, but otherwise it seems to work as it should. If the external amp is not connected, there is no sound at all if the Theremin is switched on.
Does the cabinet add anything (apart from a lot of bulk!), or would it be better to see if theremin could be restored to its original Etherwave condition, i.e. with no cabinet (so far more portable), and running on its own amplifier?
Any information/advice much appreciated!

This is a difficult post to give you a satisfactory answer. I think the design is beautiful and it reminds me that an cabinet maker has the same romantic attraction for the theremin as I do. If I saw it for sale somewhere I would have bought it to rescue her, she is a real looker!

Plug the theremin into another amplifier, my first guess the hum is generated in the existing amp. The amp needs to be directly earth grounded. What you have is more Art and if you have strong interest in learning the theremin you should purchase a later EtherWave Standard model, improvements were made over the years to make it more playable.

Christopher

Hi Christopher, and thanks for your swift response to my query.

I will try it with another amp as you suggest. I read somewhere in my initial research into theremins that keyboard amps are more suited to them than guitar amps. The one that's in the cabinet is labelled as a guitar amp, so may have been a poor choice to start with.

From what you say, it sounds as though my theremin's cabinet would have been a one-off job - I've certainly not found any pictures online of another - so I think I will leave it intact and see what can be done with the electrics to improve the instrument's performance. Even if unsuccessful, it will still be an attractive object!

Peter

"or would it be better to see if theremin could be restored to its original Etherwave condition, i.e. with no cabinet"

if you have some skils it would be better to turn the bottom cabinet (equipping it with antennae and some electronics) into separate theremin -- this is a nice ready to use cabinet with built-in amp/speaker.