Microbrute LFO sync doesn't go slow

[chipaudette]

Hi,

I recently got a Microbrute and I've been running its sequencer from the MIDI clock from my TR-707. It seems to run pretty well (though, in my few short days with it, I've really only played 16th-note steps at 100-120 BPM...maybe problems lurk in other configurations).

The problem that I'm having is that, while the LFO does sync to the built-in sequencer, I can't set it to run as slow as it should. The slowest that I can run my LFO is 1 measure...ie, for the triangle wave, I get 2 beats up and 2 beats down. The user manual states that I should be able to get it to sweep over 4 measures.

Is this a problem with my Microbrute? Or is it user error...how do I get it to sweep more slowly, yet still be sync'd?

Thanks!

Chip

[pflosi]

I think this is a terminology problem (note that I don't have a microbrute myself): what they refer to as "measure" in the manual is what you refer to as "beat". One quarter note, not a whole bar.

My indicator: they say the divisions are "4 measures, 2 measures, 1 measure, ½ note, ¼ note"; if their "measure" would be a whole bar, you'd have a big jump from 1 whole bar to half a quarter note... "4 measures" in their terminology is "4 beats" or "one measure" (or I'd say: one bar) in your terminology...

Cheers!

[chipaudette]

In terms of their divisions "4 measures, 2 measures, 1 measure, ½ note, ¼ note", there is no incongruous jump between "1 measure" and "1/2 note"...

In written music, a "whole note" is actually one measure, which is 4 beats in 4/4. So, if a "whole note" is 4 beats, then a "1/2 note" is 2 beats and "1/4 note" is one beat. This is true in American English, at least (http://en.wikipedia.org/wiki/Whole_note).

So, if we were to write out Arturia's professed LFO time divisions in terms of beats based on this long-standing definition of whole note, the LFO periods available on the Microbrute should be "16 beats, 8 beats, 4 beats, 2 beats, 1 beat". Sadly this isn't what we see...though that's certainly what I'd been hoping for.

If the Arturia engineer who coded up the LFO used your timing interpretation, we would see "4 beats, 2 beats, 1 beat, 1/2 beat, 1/4 beat". The first three definitely exist...it's the last two that I haven't check. They'd be kinda too fast for traditional LFO duties, yet not yet fast enough to enable audio rate modulation. So, IMHO, they'd be quite unusual speeds to include. I'll check it out when I get home tonight.

I suspect that my test will show that those fast speeds (1/2 beat, 1/4 beat) are indeed there, at which point your interpretation will be proven correct, which is that they don't conform to the standard written-music definition of "measure" or "whole note". That would be a bummer for me.

What I'm really hoping is that some other Microbrute owner out there does actually get a slow 4-measure sweep (16 beat sweep) when sync'd. If they do, then my unit is defective and I can get it fixed (or it's user error, which is always a possibility). That is hoped-for outcome from all this.

Can anyone with a Microbrute tell me if they can get a slow 4-measure sweep when sync'd?

Chip

[pflosi]

Yeah indeed I messed it up with my "quarter notes" above, too little coffee in the morning

My conclusion still stands though, let us know how it turns out. Synced LFOs can work as pseudo-envelopes or for ratcheting effects if you adjust the division on the go (or better, modulate it), so I think I could find use for it at 1/4 beat (1/16 note).

[meatballfulton]

It's common for the synching of LFOs at very fast or very slow tempi to not work properly at the extremes of the range because the LFO simply cannot run at the needed speed.

At 120BPM, you have two quarter notes per second. Four bars would be 16 quarters or 8 seconds. That's a frequency of 0.125Hz.

From the manual:

The LFO is designed to operate from approximately .1 Hz up to 200Hz.

So at 120 BPM it should be able to sync to four measures. Have you checked over at the Arturia Forums?

Good luck

[chipaudette]

So at 120 BPM it should be able to sync to four measures. Have you checked over at the Arturia Forums?

Yeah, I posted this over at the Arturia forum last week. It's a lot slower over there, so no action. That's why I posted it here...hoping there'd be more traffic and maybe someone who'd encountered the same problem (or maybe even had a solution!).

Chip

[dustinh]

Did you have any luck figuring this out? I recently bought a microbrute myself and did a search for this very issue and found this. I'm also trying to figure out why the lfo will only cycle as slow as 1 measure when the manual clearly says it can sync to a 4measure cycle. I really wanted a synth that could do slower synced lfos. I like that the lfo doesn't retrigger when in sync mode. I wish my mopho could do that, but as far as I know, the mopho's lfo can only be in retrigger mode with lfo sync turned on, meaning i can't play sequences over a slowly evolving lfo with either synth.

interesting note: the manual says the the sync rates for the lfo is, 4 measures, 2 measures, 1 measure, 1/2 note, and 1/4 note. The actual range is 1 measure, 1/2 note, 1/4 note, 1/8 note, and 1/16th note. Exactly 4 times faster than what it says.

[chipaudette]

No, there's been no resolution to this. I still enjoy the synth, but I sure do wish that the LFO would sync slower, as the manual says that it should.

My post on the Arturia forums has not been any help, either.

http://forum.arturia.com/index.php?topic=83268.0

Chip