Hi folks,
Just received a used etherwave plus theremin today and want to check something...
I'm finding that the theremin produces a buzz - which sounds like somewhat aggressive ground loop interference - when my right hand is just before the lowest note in the pitch range. So however I calibrate the pitch, just before I move my hand into the sub-audible range I hear this low, interference style buzzing. Once the instrument is producing audible notes the buzzing goes away completely, it's only when my hand is just about to enter the audio range.
Obviously this can be addressed as in normal usage you would calibrate in such a way that you weren't playing sub-audio notes - but I just wondered if this is normal behaviour or may suggest a fault?
For what it's worth the theremin isn't in A1 condition cosmetically, it's got a few knocks to the wood (which I knew before purchasing), and it has clearly been around someone who smokes (which I didn't) - so it's possible it's sustained some damage.
Grateful for any advice.
rb.x
Buzz / hum question
Re: Buzz / hum question
Hi restlessboy,
Hard to tell, without a sound-example ,-) But there are different noise sources i can think of:
One is that low "bup-bup-bup" motorboating-like sound. But that's a normal behavior. I enhanced my circuit-boardard with a additional bass-module. 2oct more and those bups are gone.
Another noise is "ground-hum", it's around 60Hz where I live. Mostly caused of bad grounding of the Amplifier, Theremin, FX, etc.
Fluorescent lamps, or other electromegnetic radiation sources are placed far away ? Theremins are picky. Specially around the zero-beat zone.
Another one are the so called "birdies", more higher frequencies,like radio-waves ? now that would be a badder sign, asfik.
Did you tune the internals? (L11 + L6 and that wire going to the pitch side?) or just the knobs? Maybe it needs some adjustments there. What's the frequency when you touch the pitch-antenna? round 3500 hz?
Nevermind, I smoke my Theremin since years, and it still works.
Hard to tell, without a sound-example ,-) But there are different noise sources i can think of:
One is that low "bup-bup-bup" motorboating-like sound. But that's a normal behavior. I enhanced my circuit-boardard with a additional bass-module. 2oct more and those bups are gone.
Another noise is "ground-hum", it's around 60Hz where I live. Mostly caused of bad grounding of the Amplifier, Theremin, FX, etc.
Fluorescent lamps, or other electromegnetic radiation sources are placed far away ? Theremins are picky. Specially around the zero-beat zone.
Another one are the so called "birdies", more higher frequencies,like radio-waves ? now that would be a badder sign, asfik.
Did you tune the internals? (L11 + L6 and that wire going to the pitch side?) or just the knobs? Maybe it needs some adjustments there. What's the frequency when you touch the pitch-antenna? round 3500 hz?
Nevermind, I smoke my Theremin since years, and it still works.
-
Darcmorcel
- Posts: 3
- Joined: Tue Feb 24, 2015 7:16 am
Re: Buzz / hum question
Hi, jumping in the subject a month later but it might still help !
I think it is a normal behavior as it is the same with my Etherwave; I'm no specialist but it would make sense that there's a little hum as you're just entering the electric field of the antena.
Speaking about noise issues, I'm very pleased to find that this instrument is quite silent, especially when you consider that we're dealing here with a design that is a century old
I think it is a normal behavior as it is the same with my Etherwave; I'm no specialist but it would make sense that there's a little hum as you're just entering the electric field of the antena.
Speaking about noise issues, I'm very pleased to find that this instrument is quite silent, especially when you consider that we're dealing here with a design that is a century old