Help with variable inductor alterations

Posted: 5/13/2014 10:59:11 AM

Joined: 5/12/2014

Hi, I've started building a theremin based on the design from this blog. However the TOKO T1017Z 47uh coils have sold out on Jabdog, and I can't seem to find them anywhere else (although I may be able to buy a few direct from some people). An alternative appears to be the Coilcraft SLOT TEN-5-10, and I've ordered some free samples. Their specs are pretty much the same apart from the Q value, which is lower for the Slot Ten's than the TOKO's.

What difference will this make? Will it sound different, or will it just not work at all? Are there alterations I can make or different parts I can swap out to compensate for the differing Q?

Thanks very much for any help.


Posted: 5/13/2014 11:24:48 AM

From: Austria

Joined: 10/23/2013


with the Coilcraft inductors you must change


R2, R6 and R16 (2.2k) to 




R15 and

 R19 (470 Ohm)  to 330 Ohm


Posted: 4/11/2015 8:10:29 PM

From: Essex, United Kingdom

Joined: 4/11/2015


I am a newcomer to theremin construction, but have spent some time reading various threads here in order to increase my understanding and awareness. 

The reason for posting on this particular thread is that I was also beginning to build an EM theremin based on a design from the same blog as GurtTractor, however, during the process that blog has been deactivated.

I had collected the schematics, PCB layout, and most of the parts - but was using the online list of parts instead of a hard copy! GurtTractor, do you happen to have information on the capacitors? I have about 2/3 of a list with type, capacitance and voltage, but only have the capacitances for the others.

If you had a complete list with capacitance, voltage and type, that would be most helpful.

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