Navigator Rotation

Has anyone found a way to scale Navigator’s Rotation overall range of speed to be slower? I find myself always turning the Rotation knob close to center and any voltage I put into the Rotation VC input (DC switch on) has to be heavily attenuated or it flies all over the place.

Patching a really small DC offset (Maths and such) thru 2x 5v->1v Cadet V into the Rotation VC input as above still only gets me into somewhat slow territory but it’s touchy and I can never get anything glacial going on.

I’m not certain if I’m just not patching something right on the module to achieve very slow speeds.

Also totally open to changing some values on the board if anyone knows which components those might happen to be. :slight_smile:

1 Like

I’ve had the same difficulty. I’ve had more success with software, like FFMPEG, but at some point resolution and framerate become issues. When you can increase the res and fps, as with software, that helps, but with hardware, like LZX, we’re stuck.

So I’m not even sure we want slower rotation. It just seems like it would be a nice thing to have because we imagine the video world is continuous like our sensory world. Push things like this hard enough and we’re reminded that video is discrete.

Could this be why Navigator’s rotation doesn’t go slower?

1 Like

Yeah, I feel this too! Minor changes create just drastic changes using rotation, would be great to be able to tame this a bit somehow.

1 Like

Yeah, that’s definitely part of my question. The technical demands of video are way more complicated and finicky than audio rate stuff. If it’s an inherent limitation of how ramps can be rotated with analog circuitry without it glitching out, I could understand that (and would love to know more about the theory behind it!).

I wonder how Navigator’s circuitry actually interprets voltage into the Rotation VC control, though. It doesn’t seem to be necessarily looking for a clock or periodic waveforms and it seems to shift the Rotation’s speed/direction purely in relation to the amplitude/polarity of an incoming voltage.

I’ve played with Navigator a good bit now so I kind of doubt it’s my patching technique but I would love to be proved wrong. :slight_smile:

When I have some time, I’ll pop it out of the case and see if I can trace where that Rotation VC input ends up. It’s possible it might just be some passive components that set the range but that’s totally conjecture based on fiddling around with audio rate ICs.


You could try attenuating the CV to get finer control. I don’t know how effective this would be, but it’s one of the reasons I use a passive attentuator module. I’ve just never bothered using it on the Navigator rotation CV. I guess I have enough “hot” CV sources to tame before I think about increasing the attenuation between video modules.

1 Like

Did you ever get around to looking at the back of your Navigator @rempesm & tracing the VC knob connections on the PCB? If so, did you change out any resistors or capacitors?

Would a negative offset CV slow down the rotation - is it summed with the control then clipped, or clipped then summed? edit- just realised it’s a bipolar control, so maybe CV attenuation is the answer…

This is insightful:

I’ve achieved this with audio Eurorack, for rotation of vector images:

cos(α+β)=cosα cosβ−sinα sinβ
sin(α+β)=sinα cosβ+cosα sinβ

And from reading about the navigator, a few of the Befaco A*B+C could be used for multipliers and sums to achieve Anchor and Position controls, along with a Through-Zero Quadrature LFO to provide rotation control. It’s the speed of that LFO that dictates speed of rotation… though I’m curious how the Navigator can be set to spin 8x only - :thinking:

1 Like

A friend was describing how a Frequency Shifter works the other day & I’m somehow reminded of of it because of your equation @Rik_bS.

Thw topic reminded me to dig up the pics and post this -

1 Like