Unclear sound

Hello everybody!

I just recieved my new B3 Deluxe Theremin.

I never played before... but somehow I'm not managing to get the sound clear. It always seems to have a vibration undertone (like a growl...). I don't understand if it's about the pitch knob, or maybe my amplifier? Or my calbles/connections?

Anyone knows what I'm talking about and can help me?

Thanks a lot!!!

Does the undertone have a constant pitch (60Hz, perhaps?), or does it change as you play the pitch or volume antenna?  I wonder if you might have a grounding problem.  Are both your theremin and amplifier plugged in with a 3-prong plug? 

You can also try contacting Dan directly at soundslikeburns.com for help.

No it actually varies. It's espescially in the low tones... in the high ones not present at all... That's why I thought maybe it's me... or my speakers...

Theremin and amplifier are plugged in with european plugs... so 2-prong (I live in holland). 

What do you mean with grounding? Like where it stands on?

Thanks a lot for your advices!

What make/model amplifier are you using?  Is there another amplifier that you can borrow to see if the problem still occurs with different amps?  Where do you have the volume knob set on the Burns? The volume knob on the Burns is not a volume antenna tuning adjusment like other theremins.  It is actually a conventional volume knob that adjusts the signal output level.  If it is turned full-on it is possible that you are overdriving the input stage if the amplifier.  Experiment with lower Burns volume knob settings.

Jason is referring grounding as to the polarity of the houshold alternating current.  I don't know Holland.  In the USA we have 120 Volt AC supply power.  One conductor is "hot" and the other is Return or "ground" as somewhere in the system it is tied to a copper rod driven in the ground.  We also have a third prong on the power connector that is directly connected to the copper rod in the ground.

What you need to get from this, is that it may be an issue with the power circuit in your house.  Try your Theremin on another circuit in the house, in another room.  Maybe even try it at someone elses house and see if the problem continues.

Be aware of devices that can "dirty" your power.  Try to avoid using circuits that also power fluorescent lights, televisions, computers, light dimmers, other electronics, etc.  Even if not on the same circuit, it's best to keep the theremin far away from these devices.  I've had issues in the past with a faulty surge-protecting power strip.

And, don't play next to that big fan with metal blades. ;-)

I'm sure Thierry will be along soon to straighten us all out.

Alright... I'll try out some stuff. And worst case I'll try to find some shop or people around here that can give it a look.

Thanks a lot guys!

I was about to make my own thread when I saw this.

I have exactly the same problem, but with the B3 Pro. I uploaded a short clip of the sound quality but it isn't always as bad as in the clip, I was just recording right next to my PC and a bunch of other stuff. However it always has that 'growl' to some extent.

Here's the clip: http://soundcloud.com/underworldman/theremineg

I'll try some of the things already suggested here.

That sounds like artifacts getting in through the power supply.

Since this is not the first B3 to suffer this illness, I suspect they may be built a bit light in regards to power supply bypassing.

Try a snap on choke on the power cord, close to the instrument's case. It couldn't hurt to also put them on all of the computer power cords, and anything else using a switching type power supply.

If that does not help, it may require surgery.

Just a hunch.....

Rob.