Possible EW Modification board - *continuation*

Another comment about "Claramins" (love that one!) ...

Guys like Tesla and Theremin were extremely patient and dedicated, working without most of the basic things we work with everyday. They had to wind their own coils and "design by thought experiment" and analyze by ear. They also had finicky, sometimes unreliable components to work with. In one of the photos of Lev's lab you can see rows of vacuum tubes being "burned in". I would venture to say he had quite a bit of fallout -- tubes that didn't make it through burnin.

I am sure the luthiers can relate ... patiently handcrafting wood pieces to build an instrument ... I lack the skills and the patience to do that. At least with electronics we can prototype, experiment, analyze, etc. until we get what we are trying for. We don't have to hand craft every component and toss out hours of labor when it doesn't work.

Don

Replying to Eitherspiel:

[i]"Keep in mind, also, that there are many ways to set the tone on the Etherwave "[/i]

Agreed.. Also, I think the selection of a sound is hugely influenced by the context.. Some sounds which are "horrible" in one mix, can be ideal for another.. With a Theremin playing in, say, a rock band, a pure sine wave is likely to be the wrong sound choice - and a sound rich in harmonics (even if these are harmonics usually regarded as 'unpleasant') may be the best choice.

For a solo performance, The sine or a sine-like waveform with lower harmonics, may well be the best choice.. To me, the critical aspect for solo's is not the 'quantity' of harmonic content - it is the spectrum of the harmonics.. Some harmonics are generaly to be avoided for solo instruments, as they generaly sound horrible if their amplitude is significant..

But the above is only my opinion! ;-)

[i]"The TVox is a very pure sine wave - I find this sound quite dull and boring, personally. The E-Pro can make this same sound, as can the Theremax. I wish someone would make a theremin with the rich, complex sound of the original instruments. "[/i]

Yes - I think the Tvox CAN produce "a very pure sine wave" .. but it can also produce sounds where the waveform deviates from sine, and has a higher content of (particularly) odd harmonics..

What I do not think the Tvox can do (due to the purity of its oscillators and its GENUINE analogue heterodyning) is to produce any 'dischordant' harmonics at an amplitude which is noticable.

But I have only got recordings of the Tvox, one personal encounter with it, and some pictures of its innards to go on - no schematics - and alas, I dont own one.. (If I did, I think getting my Theremin to market would probably occur in 5 years time, as I doubt I would be able to resist spending all my time playing the Tvox!) .. So I may well be wrong in what I say above.

In reply to Don..

[i]"Welcome to "the quest for golden tone" ... [/i]

LOL! :-) .. Alas, I dont think there is such a thing.. I think that many factors go to make what each individual regards as "the golden tone" - I also (and here, once again, I risk stirring things up..) think often the factors which make us believe a tone is "approaching golden" are psychological and have no basis in "reality" - it is not the sound itself which causes us to love or loathe it - it is factors completely unrelated to the actual sound which infuence ones opinion.. Factors like our ideas about how the sound is produced (eg..is it heterodyning or just a simple oscillator), about the quality of tones from other instruments from the same manufacturer, or even the consensus about the sound and the opinion expressed by a musician we admire / respect.

I have been astounded to find out just how much of my liking / disliking is influenced in the above manner.. I thought I MUST produce a heterodyning VCO, because otherwise I would lose that heterodyning "sound" - I absolutely believed that I could instantly hear the difference between a heterodyne sound source and any other...

I was wrong.. I cannot tell the difference.. The spectrum analyser cannot tell the difference.. Because there is no difference! So what do I do? - Well, I will leave the heterodyning VCO in my design.. ok, its a little more expensive.. But more people will buy a theremin which is doing genuine analogue heterodyning than one whos sound generator is a normal VCO.. And it allows me to do pre-mixer waveshaping of a kind which is not possible with any other VCO.

NO ONE would class an instrument which mixed square waves into an exclusive or (XOR) gate to give digital mixing, as a "true" Theremin.. And no serious Thereminist would even considire buying such an instrument .. would they?

Yes they would.. (probably only because they were never told whats inside it) And many would applaud the instrument, and it would be highl

... slight diversion ...

Back in the late 70s I was in the market for an electric guitar and passed on a "pre-CBS Fender Stratocaster" in favor of the Gibson L6-S that I use now. For the uninitiated this Fender was "the holy grail" for a lot of guitar players, but I passed it up because I really didn't like the way it was put together.

Had I have purchased the Fender, I could have sold it and bought about 10 other, fairly expensive guitars today! D'oh!

Moral = if you like what you hear, who cares how the designer went about producing it as long as it is reliable and sustainable.

Don

[i]"At least with electronics we can prototype, experiment, analyze, etc. until we get what we are trying for. We don't have to hand craft every component and toss out hours of labor when it doesn't work." -Don [/i]

I dont fully agree - I have a big box of Theremin prototype boards which were "hand crafted" and represent hours of labor, but were tossed out because they didnt work as I wanted, and it was easier to make a new board to try improvements than to attempt these on the existing board.. sure, we dont need to make the parts (exept sometimes the bloody coils).. but I dont think things have really changed that much..

If one is forced to use SMD - Well, you get it right first time or you throw the board away..

[i]"Had I have purchased the Fender, I could have sold it and bought about 10 other, fairly expensive guitars today! D'oh!" - Don [/i]

Is the reason that the "pre-CBS Fender Stratocaster" is now so valuable / expensive perhaps because of "the way it was put together" - Perhaps the result of this is that there are now few remaining.. and as a result their price is high. (?) - It is somewhat ironic that the products which do not survive because their construction is inferior, sometimes become valuable because this inferiority causes them to be rare.

[i]"Moral = if you like what you hear, who cares how the designer went about producing it as long as it is reliable and sustainable." - Don [/i]

Amen to that! Another moral might be.. If you want an instrument as an object for investment - buy the one which will not survive the rigors of time, pack it in cotton wool, and hide it in a deep dry hole... When it is the last surviving specimen of this instrument - your grandchildren dig it up complete with its original sealed box, manuals etc, and live in comfort off the sale.

... more diversion ...

[i]NO ONE would class an instrument which mixed square waves into an exclusive or (XOR) gate to give digital mixing, as a "true" Theremin.. And no serious Thereminist would even considire buying such an instrument .. would they?[/i]

Hahaha. I don't care for the designation "serious" - I envisage a row of po-faced thereminists staring blankly into the middle distance, and a doctor pronouncing "I'm sorry, they're in a very [i]serious[/i] condition."

(It occurs to me that you can sum square-waves to approximate a sine wave, just as you can sum sine-waves to approximate a square wave. And you can produce sub-harmonics of square waves with edge-triggered counters. Of course you'd need to start well above the audible range to produce sufficient harmonic sub-harmonics to get really tiny steps, if you see what I mean, but on the plus side, logic is cheap.)

Gordon Said:

[i]
I envisage a row of po-faced thereminists staring blankly into the middle distance, and a doctor pronouncing "I'm sorry, they're in a very serious condition."
[/i]

Oh dear! I see the funny side to this - in fact ROFLMAO!! - But, I also fear that there may be some truth in the above..

[i]"(It occurs to me that you can sum square-waves to approximate a sine wave, just as you can sum sine-waves to approximate a square wave. And you can produce sub-harmonics of square waves with edge-triggered counters. Of course you'd need to start well above the audible range to produce sufficient harmonic sub-harmonics to get really tiny steps, if you see what I mean.)"[/i]

Yes - You can, using Walsh functions, produce any waveform by mixing square waves... But there would be no point in doing this in a Theremin, as it would be FAR more complex and expensive than any other means of synthesis.

The simplest, cheapest way of producing audio from the difference of 2 high frequency signal, is to convert these signals to square waves, and to XOR them.. One can then take the resultant waveform into a low pass filter to reduce the harmonic content... "Theremins" based on this principle are usually found in the likes of "Tab" books or extremely simple hobby kits.. They would not appear (except perhaps in user contributed ideas) in more 'noble' projects such as those found in "Everyday Electronics" or other "reputable" journals. ;-)

But - The point I was trying to make is that, IF a sound produced by the above method pleases people, then it pleases them! If it is their "Golden Tone" then what difference does how this tone was produced REALLY make?

continued here (http://www.thereminworld.com/forum.asp?cmd=p&T=4138&F=3)