Completed: D-Lev Digital Theremin Prototype PIII

Posted: 5/14/2021 3:38:02 AM

From: Porto, Portugal

Joined: 3/16/2017

Awesome! Looks so nice! Really professional work!

Posted: 5/14/2021 11:04:14 AM

From: Northern NJ, USA

Joined: 2/17/2012

Beautiful work Roger!

I was going to comment on the little fold out legs, but you did so in part 2 - with tolex on top no less, you're killing me here man!

The negative LCD is quite attractive, but I wonder how well it functions on a well-lit stage or in sunlight (something I worried about early on)?  These LCDs seem to be a combination of reflective and transmissive, which is nice for all occasions.

The mike mount via adapter and T-nut is quite clever!

Are those metal knobs solid, or somehow insulated?  On my P3 I've had to remove a couple of the knobs because they were bottoming out before the encoder press click, and have noticed that grasping the bare metal encoder shaft and wiggling it around a little causes the shaft to make intermittent contact with the grounded shaft sleeve, which jiggers my body ground around enough to cause a disturbance in the force field.  Before this I assumed the encoder shafts were 100% connected to the ground tab, but apparently that isn't the case.  Have you noticed this?

I see you have a healthy ground wire running from the banana jack over to the pitch AFE and back to the volume AFE.

I assume the shallow CNC routed trough to the right of the power switch is clearance for the audio PWBs?

The I/O plate is really nice looking!  I think having the power switch a rocker on the bottom makes a lot of sense, it shouldn't be too convenient to accidentally flick, nor too inconvenient to intentionally flick.

Again, beautiful workmanship!

[EDIT] Very nice extra verbiage!

Posted: 5/14/2021 1:59:22 PM

From: Northern NJ, USA

Joined: 2/17/2012

"the white on black display is working fine under very bright LED shop lights, so I can't imagine that stage lighting could be a problem.  I am most definitely using some of these going forward - they are much better than I expected.  But for a light or white cabinet I think I would stick with the black on white.  We'll see."  - pitts8rh

Another thing that scared me away from trying negative displays was the potential (strictly in my head) of being too revealing regarding the contrast pot setting.  What's your feeling on that?

"Knobs are a problem.  I do have some black plastic, almost pointerless knobs that I like but sometimes metal just looks nicer."

I agree the metal knobs look quite spiffy!  With your mad 3D printing skilz (you have completely mastered the medium) I'd love to see you try some dappled / textured knobs.  I absolutely love my printed knobs, the giant wire nut ergonomics are about as good as it gets, and you can really pack them together on the panel without major interference issues.

Posted: 5/15/2021 9:57:15 AM

From: germany, kiel

Joined: 5/10/2007

Hats off! To both of you.

Posted: 5/16/2021 2:13:27 PM

From: Northern NJ, USA

Joined: 2/17/2012

Tell Becky "beautiful pix!"  What did she use for the neutral backdrop?

The Logo (nice!) looks like it's maybe 3D?

"3) I'm not at all happy with this horizontal layout when used on a standard mic stand.  The encoder push buttons require enough force that the whole mount flexes.  I'm going to look into using either a photo tripod or a custom wood or metal stand."  - pitts8rh

I realize the knob locations are rather baked in by the master PBW, but I was thinking (out loud) that one could maybe locate both columns of knobs to the right of the LCD?  This would position them more in the center over the mike stand mount, where there's more leverage to be had?  It would also address the adjusting hand obscuring the LCD.  But things would cramp up a bit too.  Just curious, how did you settle on the overall width of the case?

Would the mount benefit from a larger diameter interface at the wood?  Like maybe a fender washer between the adapter and the underside?

"5) Available pitch correction that is discreet and can help sweeten your sound against other accompaniment.  It's intended to put the theremin on more even ground with other instruments rather than cover up poor technique."

Au contraire! ;-)  It covers up all kinds of sloppiness, in my playing anyway.  I've noticed (for better or worse) that I use it to "form" the melody by quickly centering the notes, rather than via volume dips.  But when I'm off pitch I'm really off pitch - it's a bit of a high wire act - meanwhile my volume "technique" languishes.  (I really should develop a formal fingering technique rather than mainly using my wrist & arm - someday...)

"4) I feel that all voice presets should by default have pitch correction turned off instead of on, except in cases where a few examples are grouped together."

This is a "factory" preset issue, and I'm not exactly sure what to do about it.  Folks can certainly get fiddly and set things up however they want with the librarian software, but (except for voices that use hard quantization) the best initial pitch correction settings are a minor conundrum.  Perhaps you're right, that it should be off by default (maybe good to go, but levl[0] to defeat it).

"5) I'm grasping to think of more cons; most of the issues and these functions have been hashed out to the point that I almost feel that the D-Lev is tailored specifically for me, even though there is something to appeal to almost everyone."

You came on the project when the architecture was still fairly plastic, and you helped me immensely to implement pitch preview, the odd/all oscillator parameter, pitch correction, and many other features.  And you ferreted out issues with the envelope generator and resonator (the joys of being an alpha / beta tester).  So it actually was somewhat tailored specifically for you! :-)

Posted: 5/16/2021 7:40:25 PM

From: Berlin Germany

Joined: 4/27/2016

It's incredibly interesting how the teamwork led to this great results. Thank you for the insights into all considerations, developments, implemented modules and last but not least into the craftsmanship. This looks like a real friendship between you both and the theremin technique.

Posted: 5/17/2021 12:53:25 PM

From: Basking Ridge, New Jersey, USA

Joined: 12/12/2020

Wow! What a beautiful instrument. Your attention to detail is fantastic! I’m really eager to hear how it sounds. 

While I’ve ordered a Claravox, at this point, I’m really disgusted with Moog and have no intention of purchasing anything from them again. The amount of detail pertaining to the features of the D-Lev is far greater than Moog has provided on the Claravox and it certainly appears that you’ve greatly outdone them with your design. Moog has provided relatively little information and, other than a few teaser videos, we know relatively little about the Claravox. 

Great job! I would certainly consider canceling my order for the Claravox if there was an alternative, such as the D-Lev, available. 

Posted: 5/17/2021 6:36:09 PM

From: Northern NJ, USA

Joined: 2/17/2012

Roger has thrown his entire life into this labor of love for an extended period of time, taking on the task of alpha / beta tester, spearheading the PCB initiative, and exploring exotic cabinetry design. Many features in the D-Lev owe their existence / refinement to his keen insights and observations.  And now he's making the first demo units and editing the manual!  Roger's been an all around incredibly good friend and collaborator, and I can't imagine anyone on earth better suited to advancing this project!

ContraDude, now that my wife and I are inoculated (Wednesday will mark 2 weeks past the 2nd Pfizer shot) we're starting to let our quarantine guard down.  I'd be thrilled to have you over to our house (in Boonton, NJ) to demo the D-Lev and meet and greet and stuff!

Posted: 5/17/2021 9:30:07 PM

From: Occitanie

Joined: 3/4/2012

But please stay tuned

The case is beautifull. And the sound samples on D-Lev's website are beautifull too.
So yes, antenas are deployed and tuned

Posted: 5/21/2021 11:57:09 AM

From: Porto, Portugal

Joined: 3/16/2017


How did you select top panel tilt angle? What angle you are using in your design? Is screen visibility good enough?

What is spacing between encoders? Is it feasible?

You must be logged in to post a reply. Please log in or register for a new account.