Etherwave phones circuit

Posted: 1/26/2014 3:15:26 PM
wannes_dn

Joined: 1/12/2014

I was wondering how to add a headphones volume control knob to my self build etherwave? In the hot-rodding guide (p12.) I can find a circuit build around a TL081 opamp, but it has no pot attached.

How do they do this in the etherwave plus? Are there any etherwave plus circuits available on the web?

 

Posted: 1/26/2014 4:43:37 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

The Etherwave plus circuit is just a combination of the circuit parts which had first been published in the hotrod manual. Things like adding a volume pot seem to have been too trivial to publish them. It's a 50k log pot which has its outer pins at the original audio output and ground while the wiper pin goes to the TL082 circuit.

Posted: 1/27/2014 1:31:54 AM
wannes_dn

Joined: 1/12/2014

thank you. that's the answer i was looking for.

Thierry can you tell me wat the foil in these cabinets is for? Is it connected to the gnd signal? is it important to do this in a home made theremin?

Posted: 1/27/2014 8:06:14 AM
Thierry

From: Colmar, France

Joined: 12/31/2007

This foil is connected to ground. It forms a variable capacitor together with the antenna wire which passes above. Bending this wire closer or more far away from the foil allows to fine-tune somewhat the linearity in the highest register. 

When you build the original EM circuit with 4 x 10mH linearization coils, there is no need to put it, it won't change a lot. But if you go for the more modern variant with 3 X 10mH, you should put it, simply because this small amount of additional capacitance will make the antenna circuit more stable.

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