KB cv output calibration?

[Senojkcid]

The KB cv out on my Mother 32 is nowhere close to triggering my other synths (Oberheim SEM) in tune. I first noticed this when I tried the "Tips" on pages 11 and 12 of the manual.

TIP: By patching the KB CV output to the LFO RATE CV input, you are able to increase and decrease the LFO Rate based on the pitch of each note played.
TIP: In LOW PASS mode, with the RESONANCE and MIX controls at maximum, the VCF can be used as a Sine wave sound source. Simply patch the KB output to the VCF CUTOFF input, and patch the VCF output to the EXT. AUDIO input. Now adjust the Filter CUTOFF control to fine-tune your new oscillator.

This is the type of fun is what a semi modular is for. But not much fun when it will only play in tune for maybe 5 notes. I confirmed the drift by hooking up my SEM to be triggered by the Mother. Not super experienced in "old school" analog synth calibration, I'm told it can be a bitch.

Is this issue addressable? Is this issue addressable with the 4 "most important" calibration pots Moog made accessible?
VCO: VCO Offset, Frequency Control Gain, External 1V/Oct Gain, and KB CV Gain.

Thanks

[Ted3000]

I've never played a VCO VCF synth that has 100% perfect tracking.

Yes, the calibration tool is to scale the tracking response. It was done by a Moog tech before it left the factory, with professional meters and scopes.

I would never in a million years start adjusting those tiny flimsy trimpots. You'll end up making it worse without experience and the right tools.

It's probably the KB CV at fault, since it's that signal driving the pitch of the LFO or cutoff when you patch KB to those points.

The main oscillator tends to track very well, but feeding keyboard voltage to an LFO or filter is never going to get you perfect tuning over a large range. Even an octave is asking a lot.

That sour beating you get when you have tracked self-oscillation or audio-rate LFO tuned against the main oscillator is kind of a signature sonic element of voltage controlled synths, and I'm totally fine with it. I enjoy my full digitally controlled DCO-based Novation Bass Station II for it's juicy yet surgical sound. I like my M-32 for it's vintage free running imperfectly tracking sound.

[Senojkcid]

I hear what you are saying and could maybe accept the internal moog "tricks" to have a "second"
oscillator not be perfectly in tuning. But I should be able to hook up my vintage Oberheim SEM and the Mother 32 together and play in tune. My Prophret 5 and the SEM do when I use the P5's CV/gate outs to trigger SEM. The SEM plays in tune when trigger by my QuNexus. All three play great together when the Prophet triggers the 32 with midi and the SEM with CV. And yes the Mother 32 plays in tune when triggered "old school" through CV/gate by the QuNexus. But the CV/Gate out of the Moog's Mother 32 don't track in tune??? I must be doing something wrong!? Is the KB out not the correct CV out?

Thanks

[dumbledog]

I've noticed some real weird things happening with my Mom's KB out. Last week I was using it with my FreqBox just fine -- everything in tune perfectly. Then I wanted to use the KB out to track the filter as well so I patched KB into the buffered mult... And suddenly the KB jack didn't track the FreqBox right, even when it I took it out of the. Mult. Took a day of the Mom being unplugged to fix it, and it wasn't the first time it's happened.

Next time it happens I'll break out the voltmeter and see what's up.

[jido-genshi]

I hear what you are saying and could maybe accept the internal moog "tricks" to have a "second"
oscillator not be perfectly in tuning. But I should be able to hook up my vintage Oberheim SEM and the Mother 32 together and play in tune. My Prophret 5 and the SEM do when I use the P5's CV/gate outs to trigger SEM. The SEM plays in tune when trigger by my QuNexus. All three play great together when the Prophet triggers the 32 with midi and the SEM with CV. And yes the Mother 32 plays in tune when triggered "old school" through CV/gate by the QuNexus. But the CV/Gate out of the Moog's Mother 32 don't track in tune??? I must be doing something wrong!? Is the KB out not the correct CV out?

Thanks

You've got to remember that there were different standards of CV, especially with Vintage synths (Prophet 5, Oberheim) vs Modern Eurorack (Mother-32, et al.) Though both your Vintage synths and the Mother-32 Eurorack are 1volt per octave CV (as opposed to the Korg/Yamaha Hertz per Volt standard) my understanding is that Eurorack usually operates in a 5v range (0v to 5v, or -2.5v to 2.5v) while most Vintage synths require 10v (0v to 10v, -5v to 5v). So this could be the cause of the tracking issues, you'll need to research this more...

[DaveBee]

The manual (page 40) states that the Mother operates on a voltage of -5 to +5 for VCO control.

[Ted3000]

Interesting finding:

If I patch the KB to Mix 2, crank the mix knob all the way to left, and plug the mix out to the filter cutoff, I can play the filter's self-oscillation in perfect tune with the oscillator across a wide range. But plug KB directly to cutoff and it won't track well.

The same mixer trick is not working with the LFO speed. I can't do anything to make it track well to use as a second oscillator. Tune it perfectly against the regular oscillator, with either KB direct to speed, or KB through the VC mix trick, and then play it an octave down - LFO is sharp by nearly a semitone.

Again - this does not bother me in the slightest the way I use my M-32. Just an observation.

[Senojkcid]

jido-genshi? What happens if you trigger one mother with another? I too am getting Ted3000 results adding the VCO mix 2 in the chain. But just direct cv control mother to mother, do they track in tune?

[jido-genshi]

jido-genshi? What happens if you trigger one mother with another? I too am getting Ted3000 results adding the VCO mix 2 in the chain. But just direct cv control mother to mother, do they track in tune?

Yes, they do track in tune. I had this same question asked on Gearslutz awhile back, so I made this unlisted video a couple of months ago showing one Mother-32 KB Tracking the other through all 10 Octaves, as well as in different intervals (Fifths, etc.) and using the Glide.

https://www.youtube.com/watch?v=CGu9mlZ683o

[Loopstation]

Hello,

I purchased the Mother Moog 32 and been playing with it as a standalone unit. After this interesting learning proces I conected the mother 32 with several CV/gate synths (microbrute/MFB Nanozwerg/arturia beatseppro/Korg sq-1/Roland sh-101). I did then notice that the keys in octave position 5 sound in tune.

From the moment you go up the octave ladder the moog goes out of tune. I tested it also with midi and the problem stays.

Then I set up the Moog Mother 32 in calibration set-up and attached a tuner to the audio output and indeed the keyboard is way out of tune once you go up or down the octave position.

What shall I do now? Callibrate or not. And whitch is a good tuner to callibrate.

[sonicspacerec]

i am also having trouble with this. i posted a thread but for some reason it din''t show up after modification.

in it, i expressed my frustration at having to use a CP251 with both the mult and mixer employed (multing the pitch CV and mixing two copies of it) in order to put out the necessary voltage to drive other synths. if the Mother was putting out >=1v octave this wouldn't be a problem, as i could just use an attenuator, but i must use this expensive solution to solve what should be a simple problem.

i wish to sequence my Voyager via CV+gate from the Mother as a sort of 4-osc monster

i have tested the tracking of my Voyager + other synths with another sequencer, the SQ1, and they works perfectly, so i'm pretty sure the Voyager is reasonably well calibrated. on the other hand, the Mother will not play nicely with any of my synths. it's consistently flat when tracking higher, and only works with the CP251 patch i describes.

ideally i'd employ the CP251 for more exotic tasks such as blending CV's to send the voyager's pitch or filter.

[flatlandcycle]

This has to do with impedance matching (mismatching). You most likely need a good buffered multiple (buff mult) Eurorack module. I wish there was a less expensive solution...

You will make a big mess if your Mother-32 is already calibrated correctly. The following article has a simple multimeter test at to see if the KB out is putting out correct voltages (near bottom of page at "Measuring Tracking Errors"):

http://learningmodular.com/when-do-you- ... -multiple/

See the following video explanation:

https://vimeo.com/198236866

[conspiracytherapist]

For what its worth, I had hoped to pair my FreqBox with the Mother-32. After realizing that they would not stay in tune beyond a note or two, I just called Moog and they told me that the Mother-32 doesn't output at 1v/oct, I think they said something like 0.9v/oct.

I gave up after hearing that. As has been stated, many swear an active mult will do the trick. It is unfortunate that the mults on the CP 251 and Minimoog Voyager CV expander don't do that trick. I know the Mother-32 is for Eurorack, but I think it was a huge missed opportunity to not make the KB tracking play nice with our other Moog gear—otherwise it's a great playmate for my Voyager, Sub Phatty, and Moogerfoogers.