Burns D3 deluxe pitch tuning sensitivity.

Posted: 9/13/2022 5:11:00 PM
Yngvox Moogsteen

From: The Middle

Joined: 9/23/2021

I like many things about the D3 but find the pitch control too sensitive to the point it is very hard to set tuning.  It holds tuning well but is very hard to incrementally adjust.  Is it just mine or do all behave this way?  Is there a fix?
Thanks.  I appreciate all help.
Thanks again.

Posted: 9/14/2022 3:49:06 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

If you're handy with a soldering iron you might try replacing the null pot with a 10 turn type.

Posted: 10/13/2022 7:14:34 PM
edavid

From: Montana, USA

Joined: 9/2/2019

I don't find the pitch control to be too sensitive on the plain B3.

You might try adjusting the internal pitch trimmer... hard to see how that could give exactly the symptoms you mention, but it won't hurt to try.

Since the Burns theremins are hand-wired, they might have just messed up the pitch circuit wiring on yours.  You could open it up and take some good photos of the parts that are wired to the pitch control.

Posted: 10/16/2022 5:01:27 AM
Yngvox Moogsteen

From: The Middle

Joined: 9/23/2021

When you try to adjust the pitch the smallest you can it moves the field a foot or more.  It’s a back and forth thing till you get it set but it holds a tuning well.
It has always behaved this way.  
Thanks 

Posted: 10/16/2022 9:17:50 AM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

Yngvox I'm curious, how big is the Burns pitch field?  And is it more or less sensitive to hand gestures than other (more conventional) Theremins?

Posted: 10/16/2022 2:33:09 PM
Yngvox Moogsteen

From: The Middle

Joined: 9/23/2021

     The field is about 2 and 1/2 feet.  The octave closest to antenna is very small but playable.  Middle octaves easier to play.  Very responsive.  I didn’t know the Burns was considered non conventional.  What makes it non conventional?  It has a pleasant sound though I wish it was more adjustable but can be ran through effects to alter tone.  It also has a lower output so it can be ran into tube amps without fear of blowing it up.  Fun to mess around with for 200$.  
It stays in tune very well.  I like the Grillo instructional video they ship with for 20$.  Family business.  I called and talked to family members who handle customer support.
Thomas Grillo is just a positive guy and I like his supportive message to Beginners and all who play Theremin.
Also American made.  

I wish they still made the Burns Pro. 
Anyone know where to find one.
Thanks.....

Posted: 10/16/2022 5:35:39 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

Thanks for that feedback Yngvox!

"What makes it non conventional?"

It uses RC oscillators rather than LC, something I've never experimented with.

Posted: 10/16/2022 11:09:56 PM
Yngvox Moogsteen

From: The Middle

Joined: 9/23/2021

Thanks 
How do the two oscillators differ in functionality?  Keep it simple please in your explanation.  I really appreciate an opportunity to learn more about basic theremin construction fundamentals. 
Thanks again...

Posted: 10/17/2022 1:08:00 AM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

LC: L = inductor; C = capacitor.  L and C are inverses of each other, so when connected they transfer energy back and forth at their mutual resonant frequency, which can be fairly high voltage if both are high quality and the resonance is stimulated correctly.  High voltages and narrow resonances tend to swamp environmental interference.  An LC oscillator is analogous to a clock pendulum.

RC: R = resistor; C = capacitor.  The resistor charges and discharges the capacitor, so voltages generally don't exceed the supply, and thresholds become part of the equation, which introduces more noise & error.  Lower field voltages are more prone to environmental interference, though the RC resonance is more sensitive by a factor of the square root of 2, which may make up for at least some of the overall quality discrepancy between RC and LC.  RC is actually more flexible in terms of modulation, which could possibly be employed to further reject noise and increase sensitivity via coding gain (another entire weird field).

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