A technical support community for Apple Logic Pro users.

Topic Author
Posts: 14
Joined: Thu May 14, 2020 6:44 am

Retro Synth. Portamento. AAARRGGGHHHH!!!!

Tue Jun 16, 2020 11:55 pm

So frustrated!

Just want a simple behaviour where each 'new' note slides into itself FROM the pitch of THE PREVIOUS NOTE...!

That's how Portamento has worked on literally every other synth I've ever played (I'm in my 50s - that's a lot of synths)

Most of the patches on RetroSynth seem to either glide in one direction only regardless of the direction of the melody (like if I play a 'downward' line, reasonably expecting the glides to be downward in motion from last-played-note to next-played-note but ALL the notes glide UP from some arbitrary pitch lower down that I haven't played!)
they exhibit totally random behaviour - never the same twice when playing the same line..? and each 'new' note shooting in from a pitch way higher of lower (doesn't seem to be predictable or consistent which 'direction' the glide comes from either) than the previous note???

and then at other times not gliding at all - like, I'll play the line to 'feel out what the glides are going to sound like' before I commit the line to a midi performance - and as I play the line a few times it'll start out (the glide) shooting around all over but then as I continue playing it stops doing it all together?

Driving me bonkers!
User avatar
Posts: 4617
Joined: Mon Aug 03, 2009 2:31 am
Location: Germany

Re: Retro Synth. Portamento. AAARRGGGHHHH!!!!

Wed Jun 17, 2020 12:50 am

Yeah, but how do you *really* feel about it ?

After fiddling with this for a few moments, here is my guess:

One of the central problems of portamento is where to glide from. This obviously includes the very first note, but also, and this is where it gets far more complicated, in a polyphonic situation.

To check, set your polyphony to mono in Retro's Settings. Violà - correct portamento, on every note.

Now switch to 2-note poly and play an octave bass pattern. You'd expect that pitch would chase up and down to follow the note movement. But what really happens is that both notes slowly find their correct positions and then stay there.

This indicates that voice 1 (which plays notes 1,3,5,7,9,etc.) has its own portamento, different from voice 2 (2,4,6,8,etc.). So you hear one portamento mono synth playing notes 1,3,5,7... which is always the same note and thus portamento slowly settles on the actually correct pitch, and the same for voice 2 but one octave higher.

This applies to higher polyphony as well, but much less predictable as you'd have to somehow keep track which voice of 16 actually played which note in the past, which quickly reaches a state of complexity Mr. Rubik would be proud of.

Is this implementation a satisfying solution ? Hardly. But at least now you know what's going on.
Christian Obermaier
Contact me for private Logic Consulting, Training, Troubleshooting via Skype, Zoom or Teamviewer

1 x MacPro 6core 2010 24Gb RAM
2 x MacBookPro i7 2012 16Gb RAM
OSX.14.6. Mojave, Logic X.4.4 & 5.1
Topic Author
Posts: 14
Joined: Thu May 14, 2020 6:44 am

Re: Retro Synth. Portamento. AAARRGGGHHHH!!!!

Wed Jun 17, 2020 4:02 am

:D :D :D guess I was a bit cagey... :D
Bingo! - mono mode.
didn't know....
Thanx friend x