"[i]a nice delay pedal[/i]"
Obviously this goes to personal preference, but I mostly use a clean digital delay to bring out the interactions between the current sound and the delayed sound on held notes (i.e. beats and phasing).
Tape delay emulation is kind of irrelevant with a theremin - you don't need to introduce pitch instability - you already have it!
I use a Marshall Echohead EH1 - the output from my moog etherwave is a bit too hot for it so I attenuate the signal a touch before it gets to the pedal. (An inline volume treadle would work fine - find a volume level that works and then leave it alone.) As I said, I mostly stick with the pure digital setting, but have also had some pleasing results with the reverse setting and the modulated filter setting. Other people with opinions I respect swear by Boss.
Don't trust demos of pedals with guitars - they give no indication of how the pedal will work with a theremin. For examples of the Echohead and a theremin you could visit my youTube channel - http://www.youtube.com/gordoncharlton
Moths Are Made Of Dust - straight digital echo.
Chikhai Bardot - Mod Filter
Night Shift - reverse echo (and some other effects too)
Void Ship - ultra-short echo and max feedback to make a resonant comb filter - and then a second echo pedal with more reasonable settings.
Also wah pedals are fun with theremins. (Dance of the Flower Pot Men)
Your results will vary according to the timbre of your instrument.
Obviously this goes to personal preference, but I mostly use a clean digital delay to bring out the interactions between the current sound and the delayed sound on held notes (i.e. beats and phasing).
Tape delay emulation is kind of irrelevant with a theremin - you don't need to introduce pitch instability - you already have it!
I use a Marshall Echohead EH1 - the output from my moog etherwave is a bit too hot for it so I attenuate the signal a touch before it gets to the pedal. (An inline volume treadle would work fine - find a volume level that works and then leave it alone.) As I said, I mostly stick with the pure digital setting, but have also had some pleasing results with the reverse setting and the modulated filter setting. Other people with opinions I respect swear by Boss.
Don't trust demos of pedals with guitars - they give no indication of how the pedal will work with a theremin. For examples of the Echohead and a theremin you could visit my youTube channel - http://www.youtube.com/gordoncharlton
Moths Are Made Of Dust - straight digital echo.
Chikhai Bardot - Mod Filter
Night Shift - reverse echo (and some other effects too)
Void Ship - ultra-short echo and max feedback to make a resonant comb filter - and then a second echo pedal with more reasonable settings.
Also wah pedals are fun with theremins. (Dance of the Flower Pot Men)
Your results will vary according to the timbre of your instrument.