newbie having an … angular proble

Posted: 3/15/2021 6:09:03 PM

From: Minnesota USA

Joined: 11/27/2015

Sorry, I had forgotten that I did listen to your first clip. Your most recent clip has the theremin sounding like a kazoo.  I agree that this isn't good.

The pitch response seems to be working, even if the sound is terrible.  That's something, at least.

Since you believe this to be a result of the impact I think you may want to give it a very thorough internal visual and mechanical inspection.  This includes tugging on connectors, maybe even removing and reinserting them to refresh connections or spot possible problems.  Look for anything that could have suffered from the way it fell, knowing that anything with some mass is more likely to be damaged by a high-G impact.

The narrow CV board to which the potentiometers are soldered does contain the headphone amplifier IC but not much else in the audio path. Since the pots don't seem to be having much effect you will want to make sure that the connection from the CV board to the main board is good. Look at everything, but focus on the larger main board and the connections to antennas on both ends. These antenna connections won't affect tone, but a broken ferrite in one of the pi-wound inductors at the end could affect the response (most likely killing it though).  

What are your options for sending the unit somewhere for repair?  Did you buy it from a dealer that can direct you to a warranty facility (even though this may not be covered due to damage)?  If warranty repair is out of the question then you could probably send it to Thierry Frenkel (France) who could not only fix it and tweak it to perfection but you could have him put in his ESPE01 buffer mod that will greatly improve the instrument's linearity and tone (for a fee, of course).  Many Etherwave owners have that mod installed or something like it.

Judging by your video title I can see that you are a science/mathematics/engineering nerd (as several of us are as well). Do you have any test equipment (scope, DVM)?

Posted: 3/16/2021 1:11:48 PM

From: Northern NJ, USA

Joined: 2/17/2012

"Note to theremin nerds looking at the photos:  I had been wondering what Moog was using for the antenna inductors these days.  It looks like they have a new source or they are having them custom made.  These have natural color insulation with different slightly different cores."  - pitts8rh

Fascinating, thanks for pointing that out! 

OT, but I wonder why they didn't take this opportunity to replace the 3 with a single inductor, perhaps mounted in protective tubing or other housing?  Or at the very least run a line of splooge under them like they do the large electrolytics - anything to reduce the fragility.  The EW must be a nightmare product to support.  Even when 100% functional just tuning the thing is high art.  Imagine shipping a plastic hex tool with every AM/FM radio and expecting random folks on the street to do IF stage alignment should they accidentally jar the thing too much.[/rant]

Posted: 3/16/2021 4:54:56 PM
Halla pacha

Joined: 3/13/2021

Well to be honest I had already done a quite thorough investigation (didn’t find any connections I could’ve plugged and unplugged easily though, pretty scared of forcing something).

I think I’ll let someone more experienced handle it, it’s been taking me a lot of time/mental resources lately and the courses at uni are getting more intense.

From there I  believe I have 3 options :
1) : send it for repair at Thomann and wait for it to comeback (there’s the 30 days satisfied or money back warranty)

2) : send it back and buy a new one directly from Thierry Frenkel with the ESPE01included (it would be an EW standard though, also 100chf (basically 100$) more expensive). I originally didn’t want to do that because I wasn’t sure I would like playing the instrument (+ there is no warranty), thinking that if I liked it I could always install it at the next theremin academy in Lausanne, not quite sure if it was just a one time thing or supposed to happen yearly.

3) : I could send it to Thierry Frenkel  for the repair and ask for the ESPE01 installation (1 rock 2 birds). I couldn’t find any information on the estimated price of the repair though.

Educated opinions on the matter are welcome !

PS: I’m just a "façade" nerd, I don’t own such equipement and know anything beyond the scope of the classes I’ve taken (and I wasn’t really great at the one about electronics :angel

Posted: 3/16/2021 5:56:09 PM

From: Minnesota USA

Joined: 11/27/2015

If you want to contact Thierry you could send him a personal message here on TW, although if you are on Facebook you might try that too. I don't know what the warranty issues might be with either option but if you are on the fence you should consider that fixing a Moog theremin might not be as straightforward for a service center as repairing a Moog synth, for example, and there can be a bit of an art to it above and beyond just following a procedure in a service manual. Having your theremin fall over is probably going to cost you a bit, but if Thierry repairs it and installs the ESPE01 module (which itself is around $60) it might be a worthwhile investment even if you choose to sell the theremin later.

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