Let's Design and Build a (mostly) Digital Theremin!

Posted: 6/10/2021 7:18:15 PM
Mr_Dham

From: Occitanie

Joined: 3/4/2012

I find this question about the sound of the saxophone challenging and interesting.

The sound of the saxophone is probably not only a mater of harmonic content. Maybe a question of note transition and attack as well.

Probably not so easy to achieve on a theremin.


Posted: 6/10/2021 7:50:23 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

My bass clarinet turned out pretty good (IMO, and as far as these things go): https://d-lev.com/audio/2020-06-22_sentimental_journey.mp3

Clarinet harmonics are fairly distinctive, going from odd on the low end to all on the high end.  The alto sax harmonics (of the sample I have) change from note to note, so it's hard to know where to start (and when to stop).  There doesn't seem to be a lot of general behavior to emulate.

These discrete note type instruments are hard to play without a good, quick, precise fingering technique (something I definitely lack, hence much of the lameness in that sample above).  You can't get away with sliding all around without losing much of the realism.

Posted: 6/10/2021 8:06:02 PM
Mr_Dham

From: Occitanie

Joined: 3/4/2012


Trying an approach on my clonewheel organ :
Saxophone drawbar setting from the web = 00 2478 500

Which means:
H1 (8') = 2
H2 (4') = 4
H3 (2 2/3') = 7
H4 (2') = 8
H5 (1 3/5') = 5
("ballpark" units ...  )

No rotary sound or vibrato effect.
With some imagination we have a saxophone but I am missing the articulation effectively...

Posted: 6/10/2021 8:14:15 PM
Mr_Dham

From: Occitanie

Joined: 3/4/2012

Your clarinet sound works pretty good in fact ...

Posted: 6/10/2021 10:47:23 PM
pitts8rh

From: Minnesota USA

Joined: 11/27/2015

That bass clarinet is good...

Posted: 6/14/2021 9:08:06 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

D-Lev Kit Offering

In the past I've thought "never" to a D-Lev kit offering due to the extra support issues, but I've recently had second thoughts.  The internals and software are complete, but the realities of housing a theremin in low quantities have turned out to be harsher than expected.  I realize that most people can't be bothered to build their own housings, but a few might, and a kit represents a good opportunity for everyone.

Sticking the AFE & coil in a 3D printed box would modularize the business ends, and 3D printed control panel and tuner panel would round it out.  I could print and assemble all these things, connect them up, pump it, test it, and ship it out, with everyone secure in the knowledge that it all just works.

Folks could play it splayed out on a table, while coming up to speed and scheming their own enclosures and antennae.  They could paint the panels or make their own, but they would be starting out with something that is entirely functional.  If they don't care about looks they could mount it in any convenient box.  If they want an expensive showpiece they can contract it out to someone with fabrication experience - the D-Lev electronics and software are quite adaptable and forgiving, and the provided printed panels could simplify the enclosure design.

So a modular functioning kit seems like a fairly painless way to get some units into interested people's hands.  The initial build will be 10 kits, and I've amassed just about everything in terms of parts and tooling to do that.

The kit will be priced at $500 USD.  If that seems high, here is a partial inventory of the parts:

$25 FPGA board (currently $38!)
$11 LCD
$5 LEDs
$15 Encoders
$13 ICs
$10 Passives (est.)
$ 3 Magnet wire (est.)
$15 Connectors, wire, screws, etc. (est.)
$5 PWBs (est.)
$10 PETG plastic

Which comes to $112, and that list isn't exhaustive at all.  For instance, today I just made an order for screws, connectors, and heat shrink for over $70 - the incidentals are easy to lose track of, but they really add up.  I have to buy in small quantities, so I don't get the big boy pricing of <$0.01 per passive, and shipping tends to eat me alive too.

And of course my labor is worth something to me at least.  I figure there's a day or two of coil winding, 3D printing, soldering, and general assembly for each kit, not to mention coordination before and after the sale, packing, shipping, support in the field, etc.  (If I were a company I'd be charging for 10 years of R&D performed by a seasoned MSEE at $100/hr!).

To put the kit price in some perspective: the Etherwave main board replacement sold for around $70 and likely cost less than 1/2 that in parts.  The Etherwave Standard kit is gone, but when I bought mine years ago it was around $400 IIRC (though that included the antennas and a simple unfinished case).  So you can see that the parts of a mid-level Theremin can cost relatively little, but that a completed Theremin is sooo much more expensive than just the electronics, even when manufactured in quantity.

I'll be posting some pictures of the kit soon.  You've seen most of it already if you've been following this thread, but the AFE & coil box (sans plate antenna) have been re-engineered, and I did an initial print of that yesterday which turned out pretty nice.

Please contact me if you are interested in a kit, my email address is in my profile.

Posted: 6/15/2021 3:10:30 PM
ContraDude

From: Basking Ridge, New Jersey, USA

Joined: 12/12/2020


D-Lev Kit Offering

Just wanted the world to know that I’m first in line! 🤪

Posted: 6/15/2021 3:50:49 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

"Just wanted the world to know that I’m first in line! 🤪" - ContraDude

If you pay in full immediately, then if you are super lucky your D-Lev Centennial kit might ship next year, some time, maybe.  We're currently doing pilot production, but unfortunately you're way down on our top secret list.  And Santa says you've been very naughty.  I'm kidding, you're down as #1!  Welcome aboard! 

Just wanted everyone to know that if, for whatever reason, you don't like the kit you can return it for a full refund.  And the actual timeline for delivery is maybe a month or less.  Some parts are currently enroute from China, and the encoders should be in stock at Mouser soon.

Posted: 6/15/2021 4:04:47 PM
Buggins

From: Theremin Motherland

Joined: 3/16/2017

dewster, are you planning to include antennas and coils into kit?

Posted: 6/15/2021 4:23:48 PM
ContraDude

From: Basking Ridge, New Jersey, USA

Joined: 12/12/2020

"If you pay in full immediately, then if you are super lucky your D-Lev Centennial kit might ship next year, some time, maybe.  We're currently doing pilot production, but unfortunately you're way down on our top secret list.  And Santa says you've been very naughty.  . . . Some parts are currently enroute from China, and the encoders should be in stock at Mouser soon.

I’m sure Pilot Production must be sailing along - but what about the walnut shortage and planetary alignment? 

Frankly, I think you’re being too specific about expected delivery dates - perhaps stating that the D-Lev Centennial will be shipped by the next turn of the century would be a bit clearer?

LOL! 🤪

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