EQ settings for theremin

AlKhwarizmi,

I can't actually hear what sounds good musically. I pulled out my 10 band stereo equalizer after you brought up the subject, it's new in the box from a few years ago. I tried to enhance my sound by highlighting the frequencies of my already existing even harmonic overtones. That was disaster, it did more timbre damage because I lost quality in the sound, so I put it away.

Though I can't play, I just recorded this for you what I call "Calm Meadows in Spain". Tell me if it has a tube sound after a couple of listening passes, I add in circuit distortion to make it a little buzzy, hopefully like the original RCA I think. My speakers are desktop only a 40 mm wide and 80 mm long with a sub-woofer.

There is a character found only in tube/valve sound that I call throaty, not the semi-conductor flute or digital sound, I don't know what the proper term would be. Below is a direct feed, Radio Shack $2.19 OP Amp (TL082) fed into my cheap computer sound card.

Enigma Hybrid Tube Sound: enigma 8 .mp3 150k

Christopher

The sound is nice, although it seems to have some kind of distortion at times (not all the time, but when a note has been sustained for a while, apparently). But I don't know if this has to do with the theremin itself or with the means of recording the sound.

There is heavy distortion on the sound throughout "enigma 8". I hear a whispering "zzzzhhhh" sound accompanying the melody from beginning to end. I'm not sure what would happen to it if the sound were muted because the player does not ever bring the volume to zero.

As with the violin, so much of the general impression of the sound of a theremin depends on the skill of the player.

JeffS said:

That's the beauty of senility. You can say the same thing over and over again, and it seems like the first time you've heard it. :-)

I think we can add deafness to this aging list, I know I am not becoming like Beethoven in hearing, I hope, but as I mentioned in another thread there is a reason I own only two music CD’s or don't know any tunes to practice with.

Coalport and AlKhwarizmi mention a distortion that is heard. I have suspects and the first is my stand alone volume control uses something called “pulse width modulation” to control a Vactrol. I already have redesigned this circuit which I need to assemble. This noise would only be in a noticeable range when quieting the sound from 90% down to 25%, the "zzzzhhhh" frequency would also vary, otherwise it would quiet itself while no noise pulse exists at full volume.

Coalpoart said:
I hear a whispering "zzzzhhhh" sound accompanying the melody from beginning to end.

This points me to another possibility for the distortion. The way I try to add old time buzz. Is the distortion slightly musical or just noise?

If someone has the time and would like to be my ears for a moment do you hear distortion in this sample? I reposted in a wave format to eliminate any compressed recording issues.

Enigma Hybrid Tube Sound: enigma 8 .wav 5.6 meg  This theremin will be a future home build project.

The forums have be slow lately so hopefully this adds entertainment for all.

Thank you

Christopher

That seems to have done the trick. I still think I hear some distorsion at the beginning and the end of the audio file (the first and last second or so) but not in the rest of it...

However, I only have cheap earbuds here, not the best setup to hear subtleties.

The second sample is much better Christopher. Less distortion all round and a more pleasant sound. This tone would be rather nice if you could just learn to play the damn thing! Sorry, but you know very well that if I say anything at all I am going to be brutally frank.

Coalport are you in danger of becoming a good man?

After enough time, pressure and heat “Coal transforms into a Diamond”, for such a rare moment Jason, omhoge and Thierry used that as an excuse for website maintenance, crashed the site!#$%  then left to find a tavern.

Eight years ago a special uncle I only chatted with briefly in a USENET theremin newsgroup warned me about theremin building and wanted to know why I would want to design a theremin from scratch, then only use Radio Shack parts? How dare him!

Today after answering over a thousand builder emails during my several year theremin learning curve I too give warnings and ask similar questions. My word to those who want to build a theremin from a webpage they found is get sound bytes, don’t say you want to build it cheap, if you don’t understand electronics don’t mention how you're going to modify and improve the sound, you have no grasp of the difficulty.

Using strictly Radio Shack parts is now my past, the purpose was to teach me ingenuity.

Christopher  (-‘

The Etherwave Standard and Plus theremins tend to sound brassy because, despite the position of the timbre control, the brightest part of the sound bleeds through.  If you roll off above 7000hz, you can remove the brassiness without sacrificing the basic tone of the instrument.

The Moog theremins can be a little heavy in the baritone range -- you may want to reduce frequencies (3 to 6 db) centered around 150 to 200hz -- more reduction if you want a "stringier" sound.

In general, a little EQ goes a long way -- use a little here and there to tweak the sound as needed.

As mentioned before, vacuum tubes have characteristics that influence the tone.  In the case of the RCA theremin, the oscillators and the detector/mixer are all vacuum tubes and they all interact in subtle ways.

So, what to do?  I would suggest to imagine the timbre that you want to hear and get it as close as possible with the equipment at hand.

As much as is written about timbre, one's technique/skill has a greater impact on how the instrument is perceived than the specific timbre.

In other words, if I played on Clara Rockmore's theremin, I would NOT sound like Clara Rockmore (of course) and, furthermore, the theremin would not sound like Clara Rockmore's theremin, either.

Thanks for your input, kkissinger! Unfortunately, my EQ unit is so basic that the knobs are not marked with Hz, so one must adjust them by eye. But anyway what you say seems to match my observations, since I'm definitely rolling off the high end and I like the result (which is less brassy as you say).

I'll take a note of the frequencies in case I get my hands on a more detailed EQ at some point :)