Little Phatty Stage II CV Mod Tracking Problem

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amphonic
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Joined: Fri Feb 05, 2010 12:37 am

Little Phatty Stage II CV Mod Tracking Problem

Post by amphonic » Fri Feb 05, 2010 1:00 am

I just received my new Little Phatty Stage II with the CV Output Mod. I am having problems using it to control a Synthesizers.com Oscillator. It seems like the Little Phatty is not actually sending 1volt/octave from the Pitch CV Out. A scale starting at E tracks to 25cents short of Eb one octave up. I hooked up my handy Multimeter and it confirms my suspicion, the Little Phatty is not sending 1 volt per octave. Is there a way to calibrate the Pitch CV Out to work at 1 volt per octave?

I am pretty frustrated at this point.

Thanks
Amphonic

Sir Nose
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Post by Sir Nose » Fri Feb 05, 2010 9:33 am

I wonder if it's because the LP functions at .95 or .97 volts/octave internally. Just a tad less than 1. When the CV out mod was proposed on this forum I ask if the CV out mod would send a full 1V/octave and was told yes. This was by a member of the forum quoting info he was given by Amos.

http://www.moogmusic.com/forum/viewtopic.php?t=6931&postdays=0&postorder=asc&start=30

I sure hope it's not an issue with all CV out mods. I was hoping to get the CV out mod myself and would need to reconsider if it does not play well with others. If you have a CP-251, you should be able to play with the signal till it tracks properly. Just a lot of fiddling.

amphonic
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Post by amphonic » Fri Feb 05, 2010 9:55 am

Thanks, I dont have a CP-251 but I do have a Signal Processor to fiddle with the CV, but that is not exactly a fun way to spend the evening. The CV mod is advertised as 1volt per octave on at the Moog Music site so I am guessing mine is not quite right or I am missing something obvious.

amphonic
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Post by amphonic » Fri Feb 05, 2010 5:11 pm

Contacted Moog Support via email. It seems my Phatty was calibrated incorrectly. The fix should be pretty easy. A trim pot inside is used to adjust the volts per octave.

Sir Nose
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Post by Sir Nose » Sat Feb 06, 2010 2:53 pm

nice :)

///OSS
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Post by ///OSS » Sun Feb 07, 2010 3:15 pm

I wish that could be used for the CV ins as well, as I was never able to use the LP with other 1v/oct devices due to the .96 or .97 system it uses...sucks, as I did try with the CP but it was a pain in the arse. too sensitive and the notes just always sounded funny as it tracked up or down.
Little Phatty Stage #0042 - OS2.0 | CP-251 | MF-107 FreqBox | MF-102 Ring | MF-105B Bass MuRF

sine
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Location: Hollywood, Florida

Post by sine » Mon Feb 08, 2010 8:15 pm

amphonic wrote:Contacted Moog Support via email. It seems my Phatty was calibrated incorrectly. The fix should be pretty easy. A trim pot inside is used to adjust the volts per octave.

Can you do it yourself? If so, where is the trimmer and how do you get at it?

popgoblin
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by popgoblin » Wed Oct 09, 2013 2:16 pm

Did anybody else experience problems with the CV out? My Stage II with factory installed CV out is way off...

br
Morten

Sir Nose
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by Sir Nose » Thu Oct 10, 2013 1:27 pm

CV out should be 1v/oct.

CV in is .97v/oct or there abouts

popgoblin
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by popgoblin » Fri Oct 11, 2013 9:10 am

My problem is more that, for instance, C3 is more like "F3" compaired to other equipment.... Can that be adjusted somehow? I've tried all the calibration rutines...

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stiiiiiiive
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by stiiiiiiive » Fri Oct 11, 2013 9:56 am

Hmm… F-based keyboard on the controlled equipment, isn't it?

popgoblin
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by popgoblin » Mon Oct 14, 2013 8:13 am

F-based? Is that a thing?

My other CV-capable equipment (Elektron Analog Four, Anushri, ES-1) is waaaaay better calibrated, so the Little Phatty's... erhm "deviant" behavior surprises me....

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stiiiiiiive
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by stiiiiiiive » Mon Oct 14, 2013 4:28 pm

I saw this between some "regular" CV'd equipment and a MG-1, which is precisely F-based. As I understood your scale is right but offset by -say- a fourth (C to F), I had this idea.

Now if you think something is wrong, you definitely should write/phone to Moog techs.

popgoblin
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Re: Little Phatty Stage II CV Mod Tracking Problem

Post by popgoblin » Tue Oct 15, 2013 10:05 am

will do - thank you for your input!

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David Smyth
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Re:

Post by David Smyth » Wed Oct 16, 2013 10:28 pm

///OSS wrote:I wish that could be used for the CV ins as well, as I was never able to use the LP with other 1v/oct devices due to the .96 or .97 system it uses...sucks, as I did try with the CP but it was a pain in the arse. too sensitive and the notes just always sounded funny as it tracked up or down.


When I sent my 3 Phattys (1x Little St. II, 2x Slim) to my local Moog tech (for another problem), I also got him to calibrate all of the Pitch CV In's to 1v/octave.
It can be done.. :D

David.
NZ
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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