ForumsSoftware ← Request - option to stop oscillator

First off, excellent synth, Randy.
I don't know if this has been brought up before, but I was wondering if there could be an option to only run the oscillator when the synth receives MIDI notes.
I like to have multiple AU plugins open either on different MIDI channels or keyboard splits, and with this setup it's unfortunate that Aalto uses CPU even if I'm not playing it at the moment.
I know CPU usage is being worked on, but I think it would be nice not to have to account for Aalto's usage if I switch to another instrument (the context is in a live situation).
Thank you thank you.


Hi David,

I totally understand. I will look at solutions for you for the next update after 1.1.


I think that using the effect Bypass should be a clear way to reduce CPU usage. I have not personally tested how Aalto currently handles Bypass, but hopefully that could be implemented if it isn't already. Bypass should allow you to leave Aalto inserted in your host with a patch loaded, but taking no CPU.

Using MIDI Notes to start an oscillator can be a problem, since a long release means that the oscillators should continue to run well after the MIDI Note Off message.

There's also the consideration that an analog modular synth still runs the oscillator even when the Gate is off, allowing organic phase variations between each note - stopping the oscillator could make it less analog.


All I know is that the other AU instruments I use do not have this problem. It's possible that it's just an optimization issue, but it seems like it also has something to do with how Aalto's oscillators work. I completely understand wanting to make the synth sound as analog as possible.

"Bypass" is the name of an effect? Do you have a link? I have found no other way to have the instrument loaded but bypass it's use of CPU.

Yes, I think the most obvious solution is the optimized release of Aalto, which seems to be imminent based upon the information elsewhere on this site.

Meanwhile, "Bypass" is a concept which all DAW software implements, not the name of an effect.

In Logic, when you insert an instrument into a track and open the UI window, there is a Bypass button. This is true whether it's one of the proprietary plugins that comes with Logic, or a third-party instrument like Aalto. Bypass is available for all effects and instruments. A quick shortcut for this, without even opening the UI, is to Alt-click the instrument in the I/O insert on your track.

In Live, the concept is abbreviated to the simple universal I-O icon for a power button. When you're not using an effect or instrument, you bypass or "turn it off" to save CPU power.

I'll stop here with the specific examples, but I think you'll find that all DAW software has the same concept implemented in one way or another.

Okay, at first I thought that's what you were talking about, but then I thought that would be too easy and why didn't I think of that.

I'm using a plugin host called Rax (not a DAW) and at first it seemed like there was no option to do this. On second glance though, it looks like there is indeed an option but it isn't working correctly. I'm going to drop an email to the Rax folks and see if they can take a look at it.

Thanks for the help.

Also, thanks for looking into it, Randy.

Quick Update:

Apparently the Rax instrument bypass is not working correctly--a bug that they are working on. I booted up Garageband quick and tried the instrument bypass, and you were right rsdio, it essentially turns off the instrument.

So this should work for my purposes once it's fixed in Rax.