Need help with building a Keppinger Theremin

Posted: 6/20/2011 1:43:39 PM

From: Tucson, AZ USA

Joined: 2/26/2011

Chobbs said: [i]With tubes?[/i]

Gosh, you don’t know how many times over the past few months since I showed up at TW and someone said they wanted to build a good theremin design, I have had to bite my tongue. Hopefully raw builders are more into it for discovery.

Then someone shouts out: [b]there are many good designs![/b] hummm…really?

An Expression: “The theremin has more reasons not to work” as many of us builders know well. Then there is that brave Thereminist giving there first public performance only to find out the fluorescent light ballast over head is singing its own tune through your system!

Posted: 6/20/2011 6:33:46 PM

From: United States

Joined: 6/16/2011

Jeff S - I would wholeheartedly appreciate it if you would send your drawings to me.

Posted: 8/15/2011 4:19:51 PM

From: Richmond Hill, Georgia

Joined: 9/18/2005

I just spent 24 hours of bench time working on my Kepp....and I'm still not done. BTW, it was "completed" almost 4 years ago.

You've gotta love this stuff to be this crazy.
Posted: 8/15/2011 4:57:50 PM

From: In between the Pitch and Volume hand ~ New England

Joined: 12/17/2010

... Or you love being crazy.
Posted: 8/18/2011 12:15:24 PM

From: Richmond Hill, Georgia

Joined: 9/18/2005

You are correct, milady.
Posted: 12/5/2012 7:06:32 AM

From: Arcata Ca.

Joined: 7/5/2012

Ok so I have a question regarding the Kepp design. So There is a Vr1 which is Vo. bias and then there is Vr2 which is Vol.... This confuses me a little. I am supposing that one is for the sensitivity of the antenna and one is for the increase in db. Is this correct?



Can I just swap out R30 with a Vr so that I have a Vol. control to the Pitch preview?


There are a few changes I'm going to make. 11 pin connector not 6

Lower panel front.

Pitch preview and Vol. control

On/off switch

upper front








Posted: 12/7/2012 3:06:39 PM

From: Brooklyn,NY

Joined: 12/1/2009

I dont have the schematic in front of me- but yes volume bias is a (generally) set-n-forget trim (usually on the back of the chassis) for adjusting the volume cut off.   Volume is just volume. 


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