Actual information on Claravox

I think I might just have to bite the bullet and install virtual box with Mac OS - I didn't really want to put it on my main PC but .....

I think I might just have to bite the bullet and install virtual box with Mac OS - I didn't really want to put it on my main PC but .....

The virtualized app is certainly usable, even though wasting several gigabytes of RAM just for the Claravox editor is not an elegant solution in the long run.

Moog promised Android and Windows versions but I'm not getting my hopes up to see those any time soon.

Something a little bit interesting: I was just looking at a resource from Moog shared here: http://www.thereminworld.com/forums/T/33550?post=221044#221044

If you look at the image of the inside of the cabinet, you will see that 

1) it DOES NOT have the wire connecting the metal tab at the end of the antenna mount to the circuit board for either the volume or the pitch side

2) The USB cable goes "over" the other components rather than underneath the volume side circuit board and antenna mount.

Both of these differences match the picture I posted of my unit earlier...so i guess it wasn't a mistake, that's the way Moog was making them at one time...

It sort of leads to the question, "how did this thing ever work"? I have a guess, and it involves a different material for the volume antenna (maybe with an electrically conductive varnish?) in the very early models, such that the connection through the screw was sufficient. Then Moog switched vendors (maybe more than once) and the new antennae didn't conduct enough, but prior to shipping they tested w/ one of their original antennae. This would explain the DOA units I think.

That's not to excuse Moog, just suggesting one possible explanation of how this might have happened

"Both of these differences match the picture I posted of my unit earlier...so i guess it wasn't a mistake, that's the way Moog was making them at one time..."  - bendra

I guess I was wondering if the mistake was more one of the earlier factory assembly instructions omitting the wires, and not so much that some units squeaked through without them?  Electrically connecting the spring contacts seems essential to consistent operation, and I don't think that happens without the wires (I should have checked this last time I was in there).

"It sort of leads to the question, "how did this thing ever work"? I have a guess, and it involves a different material for the volume antenna (maybe with an electrically conductive varnish?) in the very early models, such that the connection through the screw was sufficient. Then Moog switched vendors (maybe more than once) and the new antennae didn't conduct enough, but prior to shipping they tested w/ one of their original antennae. This would explain the DOA units I think."

Any conductive metal should work the same, capacitance is all about the outer skin area of the tube (technical "skin effect" is a reduction in the effective conduction cross section with frequency, which tends to increase the resistance of inductors, a DCR adder).  I've made absolutely fine antennas from PEX plastic plumbing covered in a single thin layer of aluminum tape.  I believe the mass increase is just a supplier thing, and unless there are outer dimensional changes they should behave identically as long as the brass coating or whatever is making sufficiently good electrical contact with the mounting.  It seems reasonable to imagine that DOA units were perhaps tuned at the factory with a different "stock" antenna loop to keep from scratching up the ones that shipped, and the varnish on the shipped loop prevented good contact.  Other factory units may have been tuned with insulated loops, so the delivered units died later once the varnish wore away sufficiently.  I think that is the most likely failure scenario for Jeff's (ContraDude's) Cvixen.

Field Calibrations & Modes Questions

A couple of questions to the group that the manual doesn't seem to address:

1. The Cvox manual describes pitch field calibration procedures for both Traditional and Modern modes.  As I understand it, Traditional mode pitch field calibration is just an offset to the PITCH null knob, which allows use over a wider range of environmental capacitance.  Modern mode has a similar pitch field calibration procedure. 

My question is: Do these interact at all?  Like if you do one, do you then have to do the other for both modes to work correctly?  Or are they completely independent of each other?

==========

2. The Cvox manual describes a volume field calibration procedure for Modern mode only.  But IIRC in Traditional mode the Cvox will allow you to at least "go through the motions" by blinking the lights and responding to button presses associated with the Modern mode volume field calibration. 

My question is: A) Am I remembering this correctly?  B) If so, does it change anything in the Traditional mode volume response?

I guess I was wondering if the mistake was more one of the earlier factory assembly instructions omitting the wires, and not so much that some units squeaked through without them? Electrically connecting the spring contacts seems essential to consistent operation, and I don't think that happens without the wires (I should have checked this last time I was in there).

I understand why you would say that, and I can only reply that for me it works acceptably well without the wires. Presumably also works in the unit pictured in the Moog antenna adjustment article ¯\_(ツ)_/¯

1. The Cvox manual describes pitch field calibration procedures for both Traditional and Modern modes. As I understand it, Traditional mode pitch field calibration is just an offset to the PITCH null knob, which allows use over a wider range of environmental capacitance. Modern mode has a similar pitch field calibration procedure.

My question is: Do these interact at all? Like if you do one, do you then have to do the other for both modes to work correctly? Or are they completely independent of each other?

One does not seem to interact with the other; running calibration in modern mode does not change the pitch field in traditional mode and vice versa. I've used the calibration on each mode to make the fields somewhat similar size so I don't have to retune as much when switching from one to the other

2. The Cvox manual describes a volume field calibration procedure for Modern mode only. But IIRC in Traditional mode the Cvox will allow you to at least "go through the motions" by blinking the lights and responding to button presses associated with the Modern mode volume field calibration.

My question is: A) Am I remembering this correctly? B) If so, does it change anything in the Traditional mode volume response?

A) Had not tried until now, but I just tried and yes you can go through the steps of the volume calibration procedure in traditional mode
B) No, it does not affect traditional mode volume response - but it DOES affect modern mode response! Not what I'd expect, but there you are

"One does not seem to interact with the other; running calibration in modern mode does not change the pitch field in traditional mode and vice versa. I've used the calibration on each mode to make the fields somewhat similar size so I don't have to retune as much when switching from one to the other"  - bendra

Ah thanks for that clarification.  I've been wondering if they were somehow dependent on one another, and it makes sense that they aren't.

"A) Had not tried until now, but I just tried and yes you can go through the steps of the volume calibration procedure in traditional mode

B) No, it does not affect traditional mode volume response - but it DOES affect modern mode response! Not what I'd expect, but there you are"

And thanks for testing that!  It seems like a borderline SW bug to me, only adding to the calibration confusion.  It's too bad that they didn't make the mode switching just for the pitch side, and left the volume side essentially Modern.

I don't know, but I get the distinct feeling that no one at Moog actually plays the Theremin.  Expertise needs to be largely in-house.

"Electrically connecting the spring contacts seems essential to consistent operation, and I don't think that happens without the wires (I should have checked this last time I was in there)."

The flat springy strip goes between wood and plastic insert, and the screw that contacts the PCB also "screws through" the spring. So there is an electrical connection, but a very flimsy one. Making the cable connection did not make a difference for my Claravox, but I have no doubt that the screw/spring connection will fail over time so I added the cable anyway.

By the way, it is not necessary to solder the cable to the spring, just use a short wire, crimp a automotive 6.3mm flat terminal connector to one end and a lug to the other. Fits the end of the spring perfectly and is removable without leaving a mark.

"The flat springy strip goes between wood and plastic insert, and the screw that contacts the PCB also "screws through" the spring. So there is an electrical connection, but a very flimsy one. Making the cable connection did not make a difference for my Claravox, but I have no doubt that the screw/spring connection will fail over time so I added the cable anyway." - hudri

Ah, excellent, thanks for that info!

"By the way, it is not necessary to solder the cable to the spring, just use a short wire, crimp a automotive 6.3mm flat terminal connector to one end and a lug to the other. Fits the end of the spring perfectly and is removable without leaving a mark."

Sounds like a plan!

"I don't know, but I get the distinct feeling that no one at Moog actually plays the Theremin.  Expertise needs to be largely in-house.

I'm afraid I have to agree. FYI, Based on an exchange I had w/ Jared from Moog, I'm going to be sending my instrument to them after the holidays for all of the latest fixes and components.