MF-102 not tracking my kenton Pro-Solo MkII grrr...

[gshiff]

Hey folks,

So, I've looked through the archive and am afraid I already know the answer to this question, but figured I try anyway in case someone has some new info the share.

I've got a MF-102 (ring mod) and a Kenton ProSolo MIDI-CV. I can't for the life of me get the pitch of that internal oscillator to track properly to the Kenton. I can get one note in tune, then a note say 2 octaves up, but the notes in between are all off. I own a variety of vintage analog synths and they all work beautifully with the kenton so I'm thinking this is a lost cause, but I thought I'd throw it out there.

Reading the "Lord of Ringmod" article it talks about getting that oscillator to track the CV from a Voyager (with the CV expander so that you can attenuate the signal), just fine. So it seems that the Kenton should be able to do it too (with a bit of scaling which the Kenton does internally).

Please help!

Greg
P.S. I wrote Moog Tech support a couple of times and no one has gotten back to me, anyone else had luck with them?

[shakti]

call rudi amos or tony @ moog.
They're great!

[GregAE]

Hey folks,

So, I've looked through the archive and am afraid I already know the answer to this question, but figured I try anyway in case someone has some new info the share.

I've got a MF-102 (ring mod) and a Kenton ProSolo MIDI-CV. I can't for the life of me get the pitch of that internal oscillator to track properly to the Kenton. I can get one note in tune, then a note say 2 octaves up, but the notes in between are all off. I own a variety of vintage analog synths and they all work beautifully with the kenton so I'm thinking this is a lost cause, but I thought I'd throw it out there.

Reading the "Lord of Ringmod" article it talks about getting that oscillator to track the CV from a Voyager (with the CV expander so that you can attenuate the signal), just fine. So it seems that the Kenton should be able to do it too (with a bit of scaling which the Kenton does internally).

Please help!

Greg
P.S. I wrote Moog Tech support a couple of times and no one has gotten back to me, anyone else had luck with them?

IMO, this isn't a Moog Tech support question because you're using the RingMod in non-standard way (as an outboard tracking oscillator) with other non-Moog gear (the Kenton). AFAIK, Moog never intended for the RingMod to be used this way, but it can as the LOTRM article explains.

The RingMod oscillator doesn't track at 1V/octave (it's something less - like 0.8V/oct or something - I never measured it). This is why you have to run the Voyager Pitch CV through an attenuator to get it to work. While your Kenton will output a 1V/oct CV, it probably doesn't have the adjustability needed to reduce that CV to a workable range for the RingMod. This would explain why the Kenton works well with your other gear but not with the RM.

[GregAE]

call rudi amos or tony @ moog.
They're great!

An FYI - Rudi (Linhard) is in Germany, not Asheville, NC. He's not one of Moog's Tech Support staff. Amos or Tony are folks to contact for assistance.

Rudi wrote the Voyager firmware and occasionally participates on these forums. His company is Lintronics (http://www.lintronics.de)

[gshiff]

Greg,

Thanks for your response. You wrote the Lord of Ring Mod article didn't you? Its great, by the way.

In the article it mentions that the MF-102 oscillator tracks at slightly less than 1 v/Oct, so you run the CV out of the Voyager and attenuate the whole thing just slightly. Correct me if I'm wrong, but shouldn't that have the same effect as "scaling" the output of the Kenton (which the Kenton allows you to do in a both positive (sightly more than 1v/Oct) and negative (slightly less) way. Or does the attenuation on the VX-351 do something else all together?

I'm just wondering if perhaps there's a calibration issue with the Oscillator on my Moogerfooger (wonder if there's a way to adjust it...)

Greg

[EricK]

How far approxomately is it off?

I think without attenuation, my 102 would be like 2 octaves sharp at an octave.

Is there a way to disable the scaling function?

EricK

[gshiff]

Its not octaves off, its more like the distance between the notes is wrong, so that some notes are sharp and others are flat.

But scaled so that a low C and a C two octaves up are perfectly in tune.

And yes, the Pro Solo is quite flexible, you can disable scaling, do coarse and fine tuning on it. All the bells and whistles.

Erik, are you able to get your 102 to track properly? How are you doing it?

+G

[GregAE]

Greg,

Thanks for your response. You wrote the Lord of Ring Mod article didn't you? Its great, by the way.

In the article it mentions that the MF-102 oscillator tracks at slightly less than 1 v/Oct, so you run the CV out of the Voyager and attenuate the whole thing just slightly. Correct me if I'm wrong, but shouldn't that have the same effect as "scaling" the output of the Kenton (which the Kenton allows you to do in a both positive (sightly more than 1v/Oct) and negative (slightly less) way. Or does the attenuation on the VX-351 do something else all together?

I'm just wondering if perhaps there's a calibration issue with the Oscillator on my Moogerfooger (wonder if there's a way to adjust it...)

Greg

I did write the LOTRM article - glad you liked it.

The attenuators of the VX-351 simply turn down the voltage, nothing more.

My initial thought was that the Kenton wasn't providing enough attenuation for the RM to track properly, but then I remembered that you said you could get the scaling right for a low C and a C two octaves up, not just in between.

Is it possible that you're scaling a Hz/Volt signal instead of a V/Oct CV?

Can you try it with an attenuator?

[gshiff]

yeah, I thought that might be it, so I tried it with both settings (the Hz and Volts) neither worked properly.

I don't have a hardware outboard attenuator.

Greg

[EricK]

All that Im doing is attenuating the signal with the cp251.

[GregAE]

Your issue with the RM got me curious about the voltage needed for the RM to produce a chromatic scale, so I did a bit of experimenting.

Using the Voyager as the source pitch CV, I set up and scaled the RM as described in the LOTRM article. After a warm-up period of several hours, I rechecked the scaling. It had drifted a bit, so I re-tuned the RM oscillator, and then broke out my trusty Fluke Digital Volt Meter. I took measurements for every F and every C across the keyboard (3 1/2 octaves) giving me a total of eight measurement points (four 'F's and four 'C's).

The RM averaged 720mV/octave across the range of the Voyager keyboard. By contrast, the same test on the FreqBox averaged 998mV/octave (just 2mV less than a perfect 1V/octave). In both cases, with the voltage properly adjusted the tracking of both devices was nearly perfect over the full keyboard range. Comparing the RM with the Voyager oscillators, only a hint of beating occurred on some notes - just what you would expect from analog oscillators.

You might be surprised that the RM tracking voltage is considerably less than the 1V/octave standard, but it's important to remember here that Moog never intended for it to be used as a tracking oscillator by itself. The fact that it can be used this way extends the possible applications. (Note: The RM has no temperature compensation for oscillator stability, but nevertheless works quite well as a tracking oscillator provided it's in a controlled environment like a studio)

But here's the bottom line: in order to get your Kenton to work with the RM, it would have to scale a 1V/octave signal down by more than 25% to get to the desired 720mv/octave range. It may not be possible for the Kenton to scale that much - you may need an attenuator to knock the voltage down.

The good news is that if you're handy with a soldering iron, you can easily build an outboard attenuator for just a few dollars in parts. It's really nothing more than a small project box, a couple of 1/4" TS jacks, a 10K ohm potentiometer and some wire. Oh, and don't forget the all-important knob with the silver disc inlay (standard Moog issue).

PM me if you need more info here.

[willi]

Is it possible that the scaling being applied by the Kenton is too much for 2 octaves? I mean, perhaps it should be calibrated to a larger interval such as 4-5 octaves. I haven't used the device though so I apologize if this suggestion doesn't apply or make sense.