Newbie here: I really need help, I'm not sure what I'm doing wrong.

Posted: 3/3/2021 1:52:47 PM

From: Minnesota USA

Joined: 11/27/2015

"Is there anything else that is a "must have" in the beginning? I'm considering getting the pitch extension module, but first I need to find someone with soldering experience"

That's not a "must have" in the beginning.  First things first:

1)  Proper grounding either through a direct connect connection to an amplifier (which only solves the problem if the amp is actually grounded) or some grounded metal such as plumbing.  As DreadVox suggested, just having a long cable to an amp or your audio system can be adequate.  I've actually used a wrist strap to connect myself to the theremin ground, eliminating the need for any theremin connection to external earth ground.

2) It's important to make sure that if you made tuning changes (with the tool) to make the theremin work when ungrounded that you be able to undo those changes once you get it properly grounded.

3) The keyboard amp with a reverb is a very good idea.  Reverb is almost essential for the theremin, not for hiding mistakes as some claim but for giving you the little bit of cover that's necessary to mask pitch transitions.

4) Headphones can be a must have. Or a sound-proof room. It's going to sound ugly for a while, and some of us never want to be (or should be) heard .

When you find yourself tiring of the range of sounds available in the Etherwave, or you find the compression of notes near zero-beat to be annoying, then you may want to consider some type of modification (there are mods other than the one you have in mind).  But it doesn't really hurt to spend some time with the stock theremin. 

Posted: 3/3/2021 3:20:26 PM

From: Denmark

Joined: 3/2/2021

Thank you for the reply!

I'm feeling like I'm slowly starting to understand,  but I'm still having a hard time understanding what exactly "grounding" means. Should the theremin be touching something connected to the ground? Should I plug in a cable where the other end touches some plumbing such as a radiator? 

I just went to the music store and got something, but the guy knew nothing about theremins and he honestly just confused me further. I got a small mixer where I can plug in the theremin and my headphones and stuff, but it seems to be powered via USB, so I'll have to plug it into my computer, and I don't think it's grounded. So I'm not sure that's gonna help me.

Any chance you can suggest a keyboard amp with a reverb like you mentioned? My budget isn't super tight, but bring a University student, I probably shouldn't spend too much haha.

Posted: 3/3/2021 3:57:48 PM

From: Denmark

Joined: 3/2/2021

Yet another update: The mixer thing seems to Work! The volume antenna acts like expected, and the sound is much nicer too! There seems to be a reverb knob on the thing as well, which is cool, and it does indeed help - it seems to distort the sound slightly at higher pitches though, so I'm not sure if it's completely optimal

Posted: 3/3/2021 3:58:20 PM

From: Denmark

Joined: 3/2/2021

I have to tune it again now though, but that's not gonna be a problem 

Posted: 3/3/2021 5:22:32 PM

From: Minnesota USA

Joined: 11/27/2015

"I have to tune it again now though, but that's not gonna be a problem".

Be careful with that and keep track of your adjustments so that you can return at least roughly to where you started.  Without any test gear you are sort of working blind, and if you start adjusting more than one coil you can get lost very quickly.

Grounding is a complicated subject, but in simple terms think of you and the theremin as being part of a closed electrical circuit.  It isn't necessary for different elements in this circuit to be connected by wires, as they clearly are not with a theremin.  Your body is a conductor (albeit a poor one) that interacts with the oscillating electric fields surrounding the theremin's antennas.  But in order for the theremin to be able to generate an electric field from its internal AC voltage source (the oscillator) it needs a fixed reference for that voltage to "push" against.

Likewise, for your conductive body to be able to affect that electric field it needs to not simply follow the voltage variations as it enters the field. Your body must not be able to simply bobble along with the voltage variations in the electrical fields, but it must tend to resist them. In one way or another your body must be held nearer to the voltage reference that the theremin is pushing against.  This reference is what is usually called ground, and this term can mean different things depending on the context of the subject, which doesn't help when you're trying to understand what it is.  There are many types including earth ground, local ground, chassis ground, digital ground, analog ground, etc.  Just think of it as a reference against which all other voltages are measured.
Earth ground is what you get when you connect to something that can be traced back to a conductor that is buried in the dirt - water pipes, ground rods, or house electrical grounds (if your country has grounded mains).  A local ground (this can go by different names) is some other means of connecting yourself back to the theremin - a wrist strap, metal chair, conductive floor mat, or a wire held in your teeth (not recommended!) any of which would be connected back to the theremin's ground side. Earth ground can be the same as the local ground, and here in the U.S. that is usually the case if you ignore noise issues.  Contrary to popular belief a theremin does not need a true "earth" ground any more than a flashlight needs to be connected to a stake in the ground (though in noisy environments there may be a benefit in having an earth ground for a theremin). But like any other device the theremin does need a local ground, or a path through the player that ultimately closes the circuit.

Another way of looking at it is that the theremin can be considered a two terminal device that must have both terminals connected (not necessarily by wire) to close a circuit.  The antenna is one terminal, and that side of the circuit is closed through the capacitance created by the proximity to your arm/hand.  But what about the other terminal?  That ideally would close the circuit by direct connection to your body.  But since players generally don't like to sit in metal chairs or wear conductive straps while playing, the theremin ground-to-player connection is usually made the same way as the wireless connection through your hands to the antennas. And that's by connecting the theremin to some reference ("ground")  that your body is also connected to, by proximity and capacitance.

So in summary, your body needs to be part of the circuit between your theremin's antennas and the chassis "ground" of your theremin. A connection to the dirt, whether on Earth or Mars, or the metal floor of the International Space Station isn't an essential part of the circuit.

This is a lot like trying to define a word without using that word in the description.  But if you managed to get to the end of this maybe you'll have a better picture.  Or not .

Posted: 3/3/2021 7:06:05 PM

From: The East of Netherlands

Joined: 6/18/2019

Any chance you can suggest a keyboard amp with a reverb like you mentioned? My budget isn't super tight, but bring a University student, I probably shouldn't spend too much haha.

Behringer Ultratone K450FX, has built-in effects, including reverb, and has a headphones out option as well.

Posted: 3/4/2021 12:24:46 AM
CB Thereminist

From: Ontario

Joined: 1/28/2020

I really can't recommend enough the Fishman Loudbox Artist acoustic amp. I used a Bose S1 Pro PA speaker for a while (which I admit was a phenomenal entry speaker for practice and performance), as well as a high-end ($1400 CAD) PA speaker from Yorkville, but the Artist has my heart. I find piano speakers far too dry, personally, but the Artist is soft and full-bodied with proper EQ. It has the capacity for body-quaking lows, piercing highs, and the fullest (really excessively so) mids I've ever heard. All of which, of course, you can dial back as I do to hit a blend you're comfortable with. You could maybe look into the Fishman Loudbox Mini too, but the headroom is pretty low, so I'd recommend trying it first to test for clipping or undesirable distortion.

With regard to reverb, I personally think it's non-essential and even detrimental for practice. You need to work at getting your hands to move quickly and accurately, as with anything. Hearing ugly glisses where you don't want them is great motivation to improve. That said, for performance, some reverb can be nice to add body to otherwise dry-sounding theremins (like the Etherwave Standard/Plus without the ESPE01 module). The Artist has two types of reverb, echo, delay, two chorus options, a flanger, bypass, really responsive on-board EQ, and more. If you can afford it ($800-900 CAD new, but you can find them used (as I did) for cheaper), I'd go for it - from one Uni student to another. (:

As for the ESPE01 module... frankly, it's nice to have, but not necessary starting out. The improvements to linearity and the slightly smoother timbre are amazing to have, but they're also things you appreciate more once you're a little further into your theremin journey. For now, I would work with what you have and go from there.

Hope this helps!

Posted: 3/4/2021 12:52:57 PM

From: Denmark

Joined: 3/2/2021

Wow Pitts8rh, thanks for the explaination - I think you manager to explain it in a way that makes sense to me, I really appreciate it (:

And thanks for the suggestions with regards to amps! I think both the Behringer Ultrafine K450FX and the Fishman Loudbox are slightly out of my budget as of right now, but I shall keep both in mind as I venture Forth!

Would those amps be considered small? I live in a somewhat small apartment, so physical space also plays a role for now. 

Haha reading all these replies and my own post makes med realize how little I knew about this stuff before I went in, but I love it!

Posted: 3/4/2021 1:29:00 PM

From: Northern NJ, USA

Joined: 2/17/2012

TheDoomedPooh, I use this simple headphone amp the vast majority of the time when playing (so no one else will hear it yowling like an alley cat):

There are loads of similar products around $25 USD that probably work as well.  You would need to ground your Theremin via some other means though.  I power my Theremin via my PC USB port, which is earth grounded, and have a separate ground wire going to the AC outlet that is directly connected to my Theremin ground.

I've had some experience with the ESPE01 module (installed several, designed my own BJT version) and would caution you that, while it does expand the bass end, it also removes important timbre variation.  And it is quite expensive for what it is (2 transistor buffer, probably <$1 in parts) and the installation is rather intrusive. 

Some here were discussing a much simpler passive coupling scheme that may not throw out the baby with the bathwater:

I have no experience with it, but it seems simple enough (one RC) that almost anyone could install it, and I would definitely try that first.  You might want to play the stock instrument for a while, to have a better feel for any changes that you might make.

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