I just got a Slim Phatty and have been trying to get it working properly. I have been finding that, while oscillator 2 tracks my midi keyboard notes perfectly fine, oscillator one will not stay relative to it (or in tune at all for that matter). When I play using oscillator 2 only, all intervals sound normal. However, if I try to mix in oscillator 1 in unison, or just use it by itself it is obviously out of tune. When I turn on the synch mode, for example, and oscillator 1’s level is totally off with 2 on, pressing the synch 1>2 button will cause the note to jump by about a semitone up higher on the midi keyboard.
Playing the two oscillators together, I had thought number 2 was out of tune with 1, so I tried adjusting the frequency until they were in unison, but moving up or down say an octave on the keyboard, everything is wildly out of tune again. It seems like the scale oscillator 1 is playing is not correct as even octaves sound like they’re around a semitone off (sharp, it seems).
I tried using the autotune function, but it doesn’t seem to have helped. None of the tuning options seem to fix it, since it sounds like the intervals between notes are incorrect reltative to one another.
Has anyone else had this problem?
I even tried restoring the factory settings thinking I might have accidentally adjusted something improperly. Same issue.
Page 46 of the manual explains how to do this. This should fix it, the note calibration seems to be the solution for this one. But make sure the phatty is fully warmed up when doing this!
All is explained there, but just to be sure. This calibration will take a while, just so you know
I am running the calibration now (yeah, it does definitely take a while, ha ha). However, I had to restart it because I needed to unplug and move the synth, so before I stated the calibration again, I tried it with a keyboard and it seems like, for the most part, the notes sound right. Obviously, since the calibration hadn’t finished, some of them were still out of key, but the ones it had gone over seemed to be better.
I don’t know what the issue was with it though. Shouldn’t it have been calibrated at the factory?
I don’t know if this should’ve been done at the factory though, maybe a moog employee can tell you. But just calibrate it again and you’ll have a wonderful synth!
edit: ps: it’s analog, pure analog. Sometimes you’ll need to do this anyway, but it should be stable for a long time after a calibration. I only did it once last year, but it was only to be sure. It sounds like you really needed it though!
Well, it seems like the calibration helped, but a lot of the presets still sound way out of tune (between the two oscillators). It seems to get worse the higher up the scale I go. This is true even after leaving the SP on for several hours. I can retune the second oscillator on the presets to get them pretty close to in tune, but if I jump octaves on one of the oscillators it goes out again or if I play higher notes it also starts to go out of tune.
If you are going to try the calibration approach, it is important to do all calibration steps.
First the pitch wheel, then note calibration, then PW Amount, then Osc2 Frequency.
All of these calibrations interact to keep the instrument in tune.
If you do all of these things, following the instructions in the manual, the result should be a well-tuned Phatty.
If after all calibrations, there is still any serious detuning, it’s not correct. I would recommend to email techsupport at moogmusic dot com, in that case.
I did do all the calibrations but I did not do them in that order so I will try that next.
It seemed basically in tune a couple days ago but after i came back from a weekend trip it seems kind of out again.
For example, when i have the same waveform/note playing using the test button latched and I press the octave buttons for each oscillator, number two seems to properly go through the octaves (although the highest one seems like it might be a little flat, to my ears). Number one seems to get sharper the higher it goes, I think, but it’s hard to tell, exactly (unfortunately I don’t have my tuner handy because I am on holiday vacation) cause its far enough off that it seems like its almost going into quarter tones.
I’m going to try calibrating one more time in that order, but it seems like things are still weird.
Well, I turned it off for a little while and turned it back on. Once again, it seems like Osc 1 is way off but Osc 2 is right on.
I would say maybe it’s not warmed up enough yet but it seems to be off within itself rather than just generally off in pitch. Plus Osc 2 sounds normal…
Yeah, this seems off. Here were the autotune readings after the unit had been on for probably around 45 minutes:
2’ : 72.25
4’ : 60.01
8’ : 47.76
16’ : 84.51
Right now it seems a bit better but I’ve had it on for quite a while, now (over an hour and a half, probably).
2’ : 72.01
4’ : 59.97
8’ : 47.93
16’ :84.06
Osc 2 seemed to be in tune after maybe 10-15 minutes.
Is it possible the heater isn’t working properly on the first oscillator or something?
Ok, so I’ve been doing a little study of my SP’s tuning over time (according to the autotune function) while playing a latched note “60” in all four octaves.
I used 10 minute increments and took readings:
60 mins (Kind of weird behavior. Watched the pitch go down as I was taking the last reading, so I ended up taking them all again.)
2’ : 71.84 / 71.80
4’ : 59.81 / 59.77
8’ : 47.78 / 47.74
16’ : 83.87 / 83.82
70 mins (Similar behavior as at 60 mins but more obvious. Watched the pitch drop.)
2’ : 71.77 / 71.34
4’ : 59.75 / 59.33
8’ : ??.?? / 47.32
16’ : 83.65 / 83.36
So, I checked the fine tuning and, for some reason, it had gone down to -699 over two hours, during which time I hadn’t even touched the tuning knob and had it on auto.
After zeroing it again, things seemed to be in tune. It seems like, after 70 minutes, the tuning becomes stable, but then why is autotune dropping everything by more than a half step? I don’t understand it.
I am pretty sure the tuning knob does not do anything when in autotune mode.
Is the actual output frequency out of tune or is it that the tuning values are changing?
Are you checking the tuning by ear/with a tuner or just looking at the tuning values?
The LP autotunes itself when no notes have been played for a couple of minutes (I forget the exact amount of time it waits). It does this by muting its output and playing the calibration patch and comparing that frequency to the desired frequency. Just a few moments after turning the instrument on, your LP’s processor needs to tell the oscillator to play a note slightly higher than 60 to get a note that sounds as a 60. As the LP warms up it’s oscillators get sharper (their output frequency rises). So, to produce the desired frequency the processor needs to request a lower frequency to get the correct frequency to sound.
If you are not using a tuner/your ear and are just looking at the tuning values change, your LP is probably just keeping itself perfectly in tune.
The auto-tune has a wait time of 15 seconds no notes being played.
What you’re seeing is quite normal as the slim warms up, you’ll notice differences too between whether the studio is warmer or cooler.
I think the auto tune is a blessing - it does such a good job I’m surprised it isn’t the default setting. I love how I can leave it for a while, come back and it’s perfectly in tune - unlike how it used to be with analog oscillators.
I just wish the auto-tune had been extended to the second oscillator.
Hmm ok interesting info about how the autotune works. The problem is, though, that it seems to be taking over an hour to go from normal room temperature (It’s not cold in my house) to stable tracking of the octaves (i.e. being in tune even within itself). That doesn’t sound like the 15 minutes the manual and other users says it should take to stabilize.
I didn’t check it with a tuner because the output was muted in this mode, but I could try that today by going back and forth between auto mode and just the latched note to see if it’s dropping in pitch. However, when I decided to use the fine knob to correct it back up to 0 on the fine control value then played a note in all the octaves it sounded fine, not out of tune with the second oscillator, and every value was reading as within a few cents of where it should be, so that would lead me to believe that that wouldn’t have been the case had I left the fine value where it was. This part is weird but not really unfunctional, I suppose.
I will have to test this with an external tuner today, going back and forth.
