Etherwave Pitch Preview

Posted: 9/26/2007 9:02:34 PM
Don Bartholf

Joined: 8/9/2007

I watched Peter Pringles "How to play the Theremin" DVD, and he talks about a document that explains how to add pitch preview to an Etherewave Can anyone guide me to this document?
Posted: 9/27/2007 3:04:40 PM

From: Minnesota

Joined: 8/28/2007

I found this informaiton on the Moog Website under hot rodin your etherwave standard. Hope this helps..
Posted: 9/29/2007 8:46:12 AM

From: Kingston, NY

Joined: 2/13/2005

Recently encountered a great variation of it.

Ryan Cox at Moog came up with a brilliant variation of the mod. for my EWStand when I sent it in for a fix-up-recalibration visit and had the pitch preview added. When we discussed my use of the preview in performance with the EWPro, Ryan came up with a design that added a small amp and volume knob along with the new preview jack, and he managed to fit it all on the face plate without changing the wood case.

His volume knob design saves me having to attach a headphone amp to control the preview level in real time (with the normal mod you have to open the case and adjust a pot).

It's not in the hot rodding manual, but he should be able to describe it to you over the phone if you want to add that feature. It worked great for me and his recalibrations and cleanup made the EWStand astoundingly more playable than it was when I got it. The tech's at Moog are great!
Posted: 12/1/2007 7:12:06 PM

From: Connecticut

Joined: 10/10/2007

I'm definitely adding this to my Etherwave... When I get it...
Posted: 4/21/2008 4:28:45 PM

From: Derby UK

Joined: 2/17/2008

I am intending to add the pitch preview mod. to my Moog Etherwave standard, using the circuit shown in

If any one has done this mod. can you please advise if there is an 'optimum' place to locate the circuit board within the Theremin. I am no electronics expert, and don't want to mount it anywhere that might interfere with the oscillators etc. I also assume that it needs to be away from the volumne antenna to prevent supressing the volumne output. Any information/experiiences/suggestions most welcome.
Posted: 4/22/2008 6:31:05 PM

From: Colmar, France

Joined: 12/31/2007

I decided for me to not to use pitch preview. No risk, no fun!
Posted: 4/23/2008 4:14:55 PM

From: Derby UK

Joined: 2/17/2008

Too late! I have built the circuit and mounted it in the Theremin, and it works a treat! For anyone who might be interested it was such a small circuit board that I didn't need to 'fix' it anywhere. It is suspended in the cabinet, held in place by the wires that connect it to the main circuit board's header, and the jack socket, which I have mounted between the volume and pitch potentiometers on the front panel.
If I can do it, anyone can... By the way, the chip that is recommended (LM3080N) was a bit tricky to get, as it's apparently 'old hat' but I got one off E-bay no problem.
Posted: 4/25/2008 7:08:29 AM
Jeff S

From: N.E. Ohio

Joined: 2/14/2005

There is an option for those who would like a pitch preview for their standard Etherwave but may not feel they have the skills to make one themselves.

Mark "Thereminmaker" Keppinger has produced a limited run of pitch preview circuit boards. He says he has about 80 left at the moment.
They appear to be identical to the circuit in the hot-rodding manual except he is using a different IC chip and there is an onboard pot which allows you to set the output level.

You would still need to solder the 8-pin connector to the Etherwave PC board and install the jack. The "kit" comes ready to install, complete with instructions. The printed photo's are a little dark, but some of us do have an electronic copy that is a little clearer.

He was asking $20.00 (USD) per unit on Levnet, which includes shipping, but you will have to verify that with him. Payment is by personal check.

You can contact Mr. Keppinger at
Posted: 1/28/2014 11:58:18 AM

From: Scotland

Joined: 9/27/2012

Apologies for resurrecting this old thread but it seemed like the appropriate place to ask the question.

I have an Etherwave standard with one of Thierry’s ESPE01 bass modules fitted and am thinking of making and installing a wee module such as described in the ‘HotRod(your)Etherwave.pdf’ for letting me have pitch preview.

Would the installation of the pitch preview module be straight forward or would the ESPE01 complicate things?



Posted: 1/28/2014 12:26:01 PM

From: Colmar, France

Joined: 12/31/2007

RoyP, why don't you ask me directly? 

Basically there is no problem in coexistence of the ESPE01 module and the CA3080 based pitch preview circuit, the so-called "output amplifier for tuner" in the HotRod manual. It's rather a mechanical issue since the ESPE01 module occupies already the expansion port and it has to remain there. Thus the pitch preview circuit can be mounted vertically behind the front panel, about center position, which will minimize capacitive influence.

You'll just have to take a 4 wire ribbon cable to connect +12V, -12V, GND, and AUDIO from the expansion slot. It's best to make the soldering from the bottom side of the main PCB and pull the cable below it towards the front side.

Independent of the ESPE01 module, there are other considerations: The pitch preview (tuner output) circuit gives a line level output which is too weak to drive headphones directly. On the other side, there is a headphones amplifier circuit in the HotRod manual, but its input impedance is too low to be connected directly to the raw audio signal (it would considerably degrade it) for pitch preview. Thus, in order to have an audible pitch preview without external amplification, there are 2 options:

a) You build only the tuner circuit and connect a high impedance crystal earpiece like this one to it

b) You build the tuner circuit and the headphones amplifier circuit together and you link them through a 50k logarithmic potentiometer to adjust the preview volume.

Personally I'd go for version (a). It's cheaper and it remembers the times of electronic pioneering (which is well suited to the theremin).

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