Muff's Modules & More

drewtoothpaste · Posted: Sun May 27, 2012 7:22 pm Post subject: Moog Slim Phatty CV input?

I can't get my Slim Phatty to play notes upon CV/Gate input. Is there something special I need to turn on somewhere? The manual has generally been unhelpful here.

drewtoothpaste · Posted: Sun May 27, 2012 7:30 pm Post subject:

Addendum: I want to be able to feed it a CV/Gate sequence from my Orb (same as I send to my Roland synths or a modular) but it seems to play a sustained note which changes in pitch instead of triggering the VCA envelope with the incoming gate signal.

decaying.sine · Posted: Sun May 27, 2012 7:44 pm Post subject:

I am not sure about the voltages Drew, but is it possible the Orb doesn't appropriately trigger the Phatty because of either too low voltage or maybe bipolar CV ( -5 to +5) versus unipolar CV (say, 0 to 10 or 0 to 5)?

I don't have either synths, so just throwing some ideas your way.

decaying.sine · Posted: Sun May 27, 2012 7:48 pm Post subject:

Just looked it up and Orb looks like it sends 0 - 12V and 0 - 10V for gate and accent out, respectively.

Looks like Slim Phatty is -5 to 5.

Does that mean you need to offset the Orb voltage seriously, i just don't get it

drewtoothpaste · Posted: Sun May 27, 2012 7:55 pm Post subject:

The orb manual says it sends a +12V trigger to the Gate output when a note is played, and the Moog Slim Phatty manual says it takes a +5v trigger, but I'd guess that the Orb's gate output falls to 0 when a note turns off, since it seems to trigger my fully-analog gear OK.

I'm hoping I can just use a different type of cable (TRS with one half unpatched?) or do something in the software editor to allow it to work right.

drewtoothpaste · Posted: Sun May 27, 2012 7:58 pm Post subject:

Hmm, does the gate take -5 to +5? My manual just says "+5v trigger" but maybe this is why it's not working.

decaying.sine · Posted: Sun May 27, 2012 8:01 pm Post subject:

Do you have a multimeter to verify the Orb gate output drops to 0? I can't imagine why it wouldn't, and the evidence does suggest it does if it works with your modular.

I remember having a similar sustained note issue with my a-111 and a-190 but that was about 3 years ago, and I don't recall what caused it or how I got it working correctly.

decaying.sine · Posted: Sun May 27, 2012 8:05 pm Post subject:

drewtoothpaste · Posted: Sun May 27, 2012 8:13 pm Post subject:

I didn't see that, but it sounds like an unpatched cable might normal the gate input to zero which would mean the VCA is open.

I'm working on setting up a Euro sequencing system so offsetting the voltage inside there before sending it to the slim phatty might be a solution, seems like bad design not to let it work with normal CV/Gate signals though!

I do have a multimeter, I'll double-check the orb output next time I'm in the studio.

iamgoldman · Posted: Mon May 28, 2012 4:53 am Post subject:

be careful with sending high voltages into the slim phatty. i was sending a +8v pulse from my drone commander into its gate and fried its OSC1 circuit after a handful of uses. it does receive 0+5v, and since the orb sends +12 gate out, def attenuate or something.

EMwhite · Posted: Mon May 28, 2012 9:57 am Post subject:

Phatty Gate will accept either a 'switch close' (normal footswitch) or 5V, some say 5.1V or something obscure like that. It think it prefers a square'ish leading edge but your sequencer ought to do that just fine.

I'm sure that you know that some modules that we typically mess with are very specific about acting on a gate as it crosses 1.8V or something like that. Moog gives no specific info in this regard.

I've had issues with the gate in my Voyager Old School but after getting it serviced/calibrated, no issues but the VOS does NOT accept a switch.

My advice is to certainly keep voltage beneath 10V and better, attenuate the signal down to a tad over 5V and see what gives.

I think you were the one that posted a .mp3 audio that could be used as a sync signal, maybe have a look to see how high from a voltage perspective that rolls. Obviously, you want a gate with a given duty cycle, not just a quick pulse.

If you've got other analog gear (I recall that you do), maybe setup an LFO with a given pulse width attenuated to the 5V range and tweak it to see if you can snap Phatty to life.

CZ Rider · Posted: Mon May 28, 2012 11:30 am Post subject:

Have a Phatty here. You have to go into a menu under MIDI setup and change the gate in setting from sus.ped to gate and it should work. Just tried this out with an MS-20 LFO out into the Phatty gate in. Same result as you had, infinite sustain till I changed the setting, then it triggered from the LFO. Should work now?

UPDATE:
Just tried this with the square wave out from the MS-20 and got the same infinite sustain, although the ramp LFO out triggered fine. Also tried the clock out from an OB two voice and triggered fine also. So it still might be a gate compatability problem from the Orb? On the MS-20 the ramp LFO out is labled as bi-polar -2.5 to+2.5 and the square out is 0 to +5. The square does not seem to work unless I send it through an offset processor. Strange behavior as with a voltmeter the MS-20 square shows 0 volts at low? Must have to go just below into negative voltage to trigger? I'm stumped as to why.