# Etherwave waveform and brightness

Posted: 4/1/2018 10:29:00 PM

Joined: 4/1/2018

Hello, I have an etherwave Moog and here is forms of wave which I obtain with various regulations.
I find the strange sound and I am not sure that the forms of wave which I obtain are normal.

What do you think about it?

Thank you

Ps: I recorded the sound of my theremin directly on Audacity with the sound card of my computer.

Posted: 4/2/2018 9:34:48 AM

Joined: 4/1/2018

I think that there is one concerns with my theremin, because I cannot obtain this type of forms (the superior crest of the form wider than that of the bottom).

If there is a regulation to be made, you can explain me how to make it ? Do I have to adjust L6 and L5? I have a friend who has an oscilloscope, I can maybe see with him.
Thank you

Posted: 4/2/2018 1:40:47 PM

From: Russia, Saint-Petersburg

Joined: 6/6/2016

Hi Nicholas! There should be no pauses in the waveform. The waveform must be constant in its figure. (Excuse me, pauses in the picture waves - this is the transition to other settings.) Adjustment L6, L5 does not affect the waveform. It is possible that the fault occurs due to improper operation of the chip LM13700. It is responsible for shaping the waveform. The presented charts are not a violation.
In practice, the waveform patterns of the signal at different adjustments is conditional. Each termenvox is slightly different due to the variation of parameters of electronic components.

Posted: 4/2/2018 3:22:13 PM

From: Colmar, France

Joined: 12/31/2007

It doesn’t matter if the wider crest is on top or bottom, it’s just a mathematical inversion of the signal which the ear can’t discern. The waveforms shown in the above post are fully within the Etherwave’s specifications. Comparing these with the waveforms in the second post is just not fair, these are generated mathematically instead of real analog circuitry.

Thus, I’d say that your Etherwave is basically fine and if it sounds ugly, though, don’t look at the extremes of the waveform and brightness knobs, but check out the full range of both knobs which give an infinite range of timbre variations. And use an appropriate amplifier!

Posted: 4/2/2018 4:17:52 PM

Joined: 4/1/2018

Brilliant, thus what I obtain is normal. I do not need to adjust L5 and L6 then?
I play the theremin for 7 years and it is the theremin which we proposed.
I would like to learn to adjust him, I read that it was necessary to measure the frequency on the top of L12 and that it was necessary to find the 286 kHz neighborhood. With the friend who has an oscilloscope, we tried to adjust him in 286 kHz but Theremin seems to me too high in frequency to play. At my home I made a will and by affecting the antenna I obtain a note of a frequency of 7000Hz while it is indicated that it is necessary to obtain 3800Hz. I slightly affected L5 and L6, by keeping that I am 3750Hz but I think that I am not anymore settled 286Khz.

I intend to buy a fréquencemètre to be able to adjust my only one

Posted: 4/3/2018 10:03:32 AM

From: Russia, Saint-Petersburg

Joined: 6/6/2016

Inductors L5 and L6 are adjusted to almost the same frequency. This is about 285-286 kHz. Later, you can change the L6 value slightly for coarse adjustment of zero tone depending on the ambient conditions: humidity, a lot of metal around and so on. Unfortunately, such situations happen sometimes. To fine-tune the zero point, it is enough to use the Pitch Tuning regulator. There is another interesting possibility to change the direction of the antenna volume: quietly in the distance and loudly near. Some thereminist use this opportunity, but you have to adapt. And this is not a classic way to work with the tool.
P.S. And do not forget that the instrument must be grounded or a long shielded cable to the amplifier or a separate wire to massive metal objects, water pipes or to the ground. The sound quality depends on it.

Posted: 4/3/2018 10:39:40 AM

Joined: 4/1/2018

Thank you Valery. We adjusted L5 to 285 Khz but the sound was much too acute (touching the antenna I get 7000 Hz while it takes 3800 Hz). So I turned L5 slightly to reach 3800 Hz, I am set to 290 Khz surroundings. I'm much more comfortable playing, I was not used to having a Theremin that went up as high frequency and the last highest notes are useless. Does that sound good to you?
Ps: The zero point is correctly set.

Posted: 4/3/2018 11:08:05 AM

From: Russia, Saint-Petersburg

Joined: 6/6/2016

I agree, you could, But suggest L5 is Not adjusted often. To do this, change the L6. (Sometimes for operational adjustment of the zero point L6 in the case above it drill a small hole. The fact that the adjustment removed from wooden case and with him differ significantly. Need to frequently remove and put on after adjusting the housing to obtain the desired frequency. )
At certain values of frequency L5, the audio can just disappear. Be careful with that.

Posted: 4/3/2018 12:33:42 PM

Joined: 4/1/2018

Ok, thank you

I am reassured for my settings, I love this model of theremin, before, I played with a B3.

Posted: 4/3/2018 6:51:50 PM

From: Russia, Saint-Petersburg

Joined: 6/6/2016

Oh! .. B3! I have this model. B3 is very sensitive to power supply. Linearity is not very good either ...

P.S. If you want to improve the sound and expand the range at low frequencies, pay attention to the module Thierry: "ESPE-01". It is quite easy to install in Etherwave.

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