MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

BEMI Easel 1.2v or 2v per oct?
MUFF WIGGLER Forum Index -> Buchla, EMS & Serge  
Author BEMI Easel 1.2v or 2v per oct?
musicalfungus
Ive owned the Synovatron CVGT1 for a while now but have never really used it very often. I began to use it heavily and I have discovered that my Easel (2016 Bemi) appears to be calibrated to track at 2v/oct instead of 1.2v/oct. I always thought the Easels were 1.2. But maybe they differ from batch to batch.

I discovered this while trying to get a eurorack oscillator (Make Noise DPO) to track alongside the Easel. Sending a sequence from eurorack with Rene to the Synovatron CVGT1 and to the DPO. When the Synovatron is set to scale at 1.2v I can never get the notes on each voice to be in tune with each other. But if I set the Synovatron to scale the sequence to 2v then the voices easily tune into unison and they each happily play the sequence together.

Maybe I'm not using the Synovatrons offsets right? Or may I was just wrong about the Easels being 1.2v/oct. Either way I just wanted to leave that bit of info here for anyone else who may be trying to sync their easel to eurorack with the CVGT1 and having issues with notes tracking properly.
papz
Does your Easel well track with the 218 keyboard ?
Unless there were recent changes, the 218 in the BEMI Easel outputs 1.2V/oct.
You can check this by measuring the output voltage with a multimeter : 0V for the lowest key, 1.2V one octave higher, 2.4V 2 octaves higher etc...

The 208 should track 1.2V/oct as well, but some BEMI Easels come obviously uncalibrated and don't even track on 1 octave with the 218.
memes_33
i believe some original buchla VCOs were 2v/oct, but not sure why a new BEMI one would be like that. did you purchase it second-hand? maybe previous owner changed it?
musicalfungus
papz

When using the 218. It appears to track just fine. It's only when I'm trying to get it to play nice with eurorack via the Synivatron CVGT1 module that the 2v setting seems to work best. But as I mentioned. Maybe I am using the offset switches wrong in the CVGT1 module. I will explore more tonight.

In regards to checking with a multi meter. Would I just connect a multimeter probe to the end of the banana jack coming from the "main" output on the 218? Then press keys to see the coresponding voltage?
papz
Yes, the red probe in the main voltage output banana socket and the black probe in the ground banana socket.
Drillionaire
Maybe you mentioned it and I didn't see it, are you connecting the output of the CVGT1 to the keyboard input or the frequency inputs for the individual oscillators?
musicalfungus
Drillionaire

I am using the frequency inputs for each oscillator. I have actually not tried sending it directly to the keyboard input. Not sure why I've never thought of that haha. But I will try that when I get home. Are you thinking that the keyboard input may have different voltage scaling then the frequency inputs?

I played around a little more last night and found that I can actually track alongside the eurorack oscillators pretty damn well while set to the 1.2 scale setting. (through the frequency inputs) Not sure what I was doing the other night that made the 2vt setting so much more effective. I think I just needed to be more patient with my tuning and possibly had some timbral/harmonic side bands being created by modulation that threw off the tuning as well. Using simpler waves the tracking was pretty spot on.
papz
The keyboard voltage input is calibrated for 1.2V/oct tracking.
The frequency and pitch CV inputs are attenuated by the slider, these are thus variable and not calibrated for a defined tracking.
You should patch the CVGT1's output into the keyboard input to get 1.2v/oct tracking.
musicalfungus
papz

Thank you for the knowledge!

I will now plug the CVGT1 CV directly to the keyboard input for proper 1.2v tracking. Makes sense why the 2vt setting worked for me though. I must have just been attenuating the 2vt signal down to the correct 1.2 through the frequency slider CV.
Drillionaire
musicalfungus wrote:
Are you thinking that the keyboard input may have different voltage scaling then the frequency inputs?


I believe they do, and they're variable, as papz mentioned.

I believe the scaling on the frequency modulation scale slider, and frequency sliders were affected by the change from uA726 to SSM2212 matched pairs, and was never compensated with correct resistor value changes. This is also why the FM depth of the modulation oscillator to the complex oscillator is very weak when using the 'modulation' slider in the MO section as compared to patching the modulation oscillator banana to the CO pitch input directly.
musicalfungus
Drillionaire

Interesting. I will have to test that out tonight and see the difference in FM depth that can be achieved by routing directly out of the MO banana output vs the slider.
musicalfungus
Drillionaire

WOW! The modulation depth is VASTLY superior when routing directly from the MO banana output to pitch input vs using just the slider and internal routing.

I also sent the sequence from eurorack directly to the Keyboard input and the tracking is PERFECT!

Thank you!
MUFF WIGGLER Forum Index -> Buchla, EMS & Serge  
Page 1 of 1
Powered by phpBB © phpBB Group