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Upper Note Limitation

Posted: Mon Aug 13, 2012 9:43 am
by Richard J
Obviously the Minitaur is billed as a bass machine - and definitely no complaints there - but what was the point of arbitrarily restricting the oscillators to only play up to a certain note value?

I think it would sound excellent in the higher registers, especially when combined with some audio-range LFO, detuning, etc, etc.

Anyone have any info on the Moog policy in this regard?

I'm guessing the upper limit of playable notes is controlled digitally within the unit, but I'm not sure. Anyone have any info on this?

Anyone 'considered' how to work around this issue to extend the functionality of the Minitaur?

Anyone had any feedback directly from Moog reps on this issue?

R

Re: Upper Note Limitation

Posted: Mon Aug 13, 2012 10:35 am
by MC
The upper limit has nothing to do with "moog policy".

The limit is due to circuitry. Moog went to great lengths to replicate the original Taurus pedals. The oscillators were v/hz in contrast to the more common v/oct. V/hz is cheaper to build, lent itself easily to the one octave pedalboard, and lack of LFO/pitch bend (in the original) did not require v/oct. But V/hz has a smaller pitch range because the voltage doubles for every octave and you quickly reach the power supply voltage, and you can't go higher than that. That's why it has an upper limit.

Re: Upper Note Limitation

Posted: Mon Aug 13, 2012 7:03 pm
by thealien666
MC, are you telling us that the Minitaur has an internal V/oct to V/Hz converter for its oscillators ?

Re: Upper Note Limitation

Posted: Mon Aug 13, 2012 10:34 pm
by MC
If it is similar to Taurus 3, then yes.

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 1:46 am
by Richard J
But is this consistent with the fact that the Minitaur has a CV/Gate input?

Does this imply it is actually a v/oct system?

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 6:43 am
by smut
interesting to read about this matter. Certainly, moog is smiling from the background.

If the limitation has to do with "moog policy", I cannot underline this. There are no really overlapping features to other moog stuff, e.g. to the SP. The differences are to huge (different sound, storing, Filter 6-24, overload, arp, less hidden knobs...)

I cannot belive on the technical side, that there is no possibility to unlock this limitation. Maybe, someone comes out presenting a solution, even it is not an ordenary OS.

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 9:34 am
by MC
Richard J wrote:Does this imply it is actually a v/oct system?
The CV jacks are v/oct and is converted to v/hz internally
smut wrote:I cannot belive on the technical side, that there is no possibility to unlock this limitation. Maybe, someone comes out presenting a solution, even it is not an ordenary OS.
There is nothing to be unlocked. It's an inherent limitation of the v/hz system and opamp technology. For every descending octave, the voltage halves. Assuming maximum power rail of 12V and a design top pitch at 12V, each descending octave goes 12V, 6V, 3V, 1.5V, 0.75V, 0.375V, 0.1875V. As you descend in the lowest octaves you are creeping into the microvolt offset error domain of opamps. Offset error is a necessary evil of opamps and cannot be avoided. To compound the problem, offset error will drift so you can't implement an auto-correction factor with software. Offset error translates to tuning error. The lower you push the v/hz oscillators, the worse the tuning. That is why v/hz oscillators have a limited range of useable frequencies. We've known this since the 1960s.

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 10:12 am
by smut
o.k. seems to be no posibility. What a bummer!
Do you think, the sound of the minitaur would be different with OSC v/oct ?

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 10:50 am
by MC
Yes and no.

A v/hz oscillator is essentially a v/oct oscillator with the omission of the linear voltage to exponential current converter. That converter has zero impact on the timbre of the oscillator.

However there are timbre differences between oscillators of different waveshaping designs. The timbre of a ramp with distorted shape is going to sound different than a clinically shaped ramp with perfectly straight edges. The impedance coupling between stages also impacts the sound.

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 1:02 pm
by smut
you are well informed, thanks a lot!

If there is no technical way inside the minitaur to play the upper notes, it would be necessary to switch off the upper notes? Now it plays the middle C on every higher key.

I love the sound very much and I'm thinking about to play these higher notes extern by pitch or something with pitched samples and the lower ones out of the minitaur. It may make no sense but it is just a crazy idea. :idea: In this case, upper "silent notes" out of the minitaur are required.

Re: Upper Note Limitation

Posted: Tue Aug 14, 2012 3:22 pm
by Richard J
All sounds very technical..!

I had no idea it was constructed like this.

As for the upper note, I have actually used this limitation to my advantage, ie by having Osc 2 detuned by an octave while Osc 1 is fixed. I can then play a melody in C on Osc 2 whilst Osc 1 holds the note.

I'm still unsure how the unit knows that at a certain point, the Osc's shouldn't play any higher.

I have read all the technical replies so far, but I would love to hear what Moog (Amos et al.) could tell us.

R

Re: Upper Note Limitation

Posted: Wed Aug 15, 2012 9:34 am
by _DemonDan_
smut wrote:If there is no technical way inside the minitaur to play the upper notes,
it would be necessary to switch off the upper notes? Now it plays
the middle C on every higher key. :idea: In this case, upper "silent notes"
out of the minitaur are required.
Hi smut,

Since there is no built-in keyboard, I'm assuming you are using a MIDI
controller keyboard.

Many of them allow you to set the playable range for a particular "Zone",
"Timbre", "Part", etc. (depending on brand).

Simply set the High range to that C and no MIDI notes above that will go
to your Minitaur (and thus, "silent notes").

You can then add a second "Zone", "Timbre", "Part", etc. on your controller
that only plays the upper range of MIDI so that it can play a different synth.

Re: Upper Note Limitation

Posted: Wed Aug 15, 2012 12:28 pm
by smut
@_DemonDan_:

Thx for your answer.

Of course, I use a midi controlled keyboard and controll all - including the hidden knobs and can store "patches" for a quick select. Very comfortable without the editor software.

I know to split the keyboard but not all have this possibility. I only try to figure out all for playing the full range of octaves. :roll:

Re: Upper Note Limitation

Posted: Wed Aug 15, 2012 12:50 pm
by _DemonDan_
smut wrote:I only try to figure out all for playing the full range of octaves.
If you're willing to get a little tricky, you can squeeze
three more notes out of the Minitaur:

Turn the Fine Tune up so that C now plays Eb.

Now set the transpose on your MIDI controller to play
three half-steps lower.

You can now play up to the Eb above that C.

Re: Upper Note Limitation

Posted: Wed Aug 15, 2012 2:35 pm
by Richard J
Yes - thought about that, but hadn't tried it yet.