Ghost_the_garden wrote: ↑
Mon Jun 28, 2021 12:06 am
Still no report on whether this works with metasonix modules? Wouldn't it be crazy if this thing could coax melodic lines out of an r-54!? I'd test if out if some one sent me the module~for research! (:
TLDR: Yes, you can (but it was a bit tricky)! Sorry, I sort of promised to get back about this. I posted a month ago about it in the Metasonix fb group:
https://www.facebook.com/groups/2183255 ... 998407820/
If you can't access it, here's the text part of my fb post, but I can't post the video here (may upload to youtube or something, but can't do that right now):
Klavis Caltrans as pitch CV controller for Metasonix oscillators
Playing Metasonix modules melodically has always been a challenge, and sometimes takes lots of calibration. Or you sync them with a pulse from another oscillator into the pitch input. I've been exerimenting with self-adaptive real-time patches in the Nord Modular, but that may not be available for everyone.. The small module maker Klavis has a 4ch trainable voltage mapping module (ca €150), and I bought one to try with Metasonix. Here's a test with R55.
During training, the Caltrans basically runs through the CV input range of an oscillator while listening to it, and it finds out how far it goes and which voltage corresponds to which pitch. You can hear that process in the beginning of the video. Sort of like the old Metasonix R60 module, but faster, cheaper, with four channels, and with presets, octave control, transposition and portamento/glissando. After training and setting trasnposition right (on the Caltrans octave and semi knobs), you feed it normal V/oct pitch CV, and it translates it to whatever needed.
It took some tries before I found the right settings on the R55 (gain & master tuning), but finally I was able to get a little bit more than 3 octaves of OK tuning, as demonstrated in the video. During training I have the overdrive set do 0dB, and I run the oscillator through an LPG to remove higher harmonics before it hits the Caltrans training input.
In the video, the CV and arpeggiation is generated from a Squarp Hermod (V/oct out, played from a MIDI keyboard).
I was able to get it working with the R54 too. Most likely it will work with RK4 and RK7, as they contain similar circuits, but I don't have them so I can't try.
The tuning isn't perfect, as these tube monsters are inherently unstable. But the Caltrans helps a long way towards playability. One minor error source may be that the pitch is vactrol-controlled inside the R-modules (?) and that the Caltrans maybe doesn't wait until the vactor fully stabilizes, Not sure.
Note that you can use one Caltrans on four oscillators simultaneously, as it has four individually trainable channels. And the whole setup can be saved in one of four presets. It can also be used to play in pitch on feedback circuits, and other weird patches. Anything that oscillates and where the pitch is controllable by some CV.