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Author Topic: Microbrute Tuning and Pitch Out Voltage  (Read 138 times)

kwtsh

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Microbrute Tuning and Pitch Out Voltage
« on: August 24, 2014, 06:03:50 am »
Hi

Bear with me please, relatively new to CV gear...so this might be me, not the brute!

Trying to patch the Microbrute and Minitaur together. First things first, checking the tuning on the Microbrute.

I understand gate out is 0-5V, but pitch can go up to C7 on the keyboard = 7V supposedly, The Moog is 0-5V. Can this damage the Minitaur in any way?

Brute has been on for several hours.

Here's my results, confirmed with a tuner and a multimeter on the brute's Pitch Out, reference values first, mine right of midi note numbers. As you can see the frequency accuracy across the range is OK. up to 28 cents out at times in the lower registers of C0 AND similar on C1, but higher, not more variance than 13 cents on C2 then around 2-7 cents for all the rest. What's odd is the voltage being output seems to be wildly off from the reference value.

Also odd:

Gate Out is either 0.15V or 14.77V! I was expecting 0 or 5V? Very confused! Now worried about damaging the Minitaur.

What should I do to fix this? Is there a calibration procedure to follow? Would it help?

C0 = 16.35Hz -> 0V -> midi 12 > 16.62 > 0V
C1 = 32.7Hz -> 1V -> midi 24 > 33.20 > 1.24V
C2 = 65.4Hz -> 2V -> midi 36 > 65.92 > 2.47V
C3 = 130.8Hz -> 3V -> midi 48 > 131.21 > 3.71
C4 = 261.62Hz -> 4V -> midi 60 > 262.0 > 4.96V
C5 = 523.25Hz -> 5V -> midi 72 > 523.5 > 6.2V
C6 = 1046.5Hz -> 6V -> midi 84 > 1050.0 > 7.45V
C7 = 2093Hz -> 7V -> midi 96 > 2100 > 8.7V
C8 = 4186Hz -> 8V -> midi 108 - How can I check these?
C9 = 8372Hz ->9V -> midi 120 - How can I check these?

As I say, am pretty new to Analog gear (oh the revival!), so this could easily be my lack of understanding and nothing wrong with the gear. I certainly don't understand what I'm seeing, so can anyone correct my understanding or help me out please?
« Last Edit: August 24, 2014, 06:14:44 am by kwtsh »

Bruno@arturia

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Re: Microbrute Tuning and Pitch Out Voltage
« Reply #1 on: August 27, 2014, 02:47:49 pm »
you should definitely check you voltmeter calibration, 14.7V is not possible, as the internal power supply is only 12V....

every other CV values you measured seems strangely very high too.
Bruno
Arturia Hardware

kwtsh

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Re: Microbrute Tuning and Pitch / Gate Out Voltage
« Reply #2 on: August 27, 2014, 09:34:59 pm »
Hi Bruno

Thanks for that. The multimeter I'm using doesn't have any means to calibrate that I can see, so I grabbed another and tested the PSU. Originally multimeter was 13,77V, new one was 12.2. So definitely a dodgy meter problem, thanks!

Using the new meter I've just had a very quick look and the tracking of the octaves seems much closer to the reference values, will go through them all tonight.

Checking the gate out however (rear) I still get 0 or 10.2V. I thought it was 0-5V, at least that's what's the manual says for gate out???I don't want to pop the protection diodes on the minitaur which is only expecting 5v. What am I seeing here? Is the manual wrong?! If so that's not cool.

I happen to have a CP251 with attenuators at hand so at least I can work around this.

Please confirm what Arturia believe to be the correct gate out voltage on the Microbrute.

Thanks, Jon
« Last Edit: August 27, 2014, 09:56:06 pm by kwtsh »

Bruno@arturia

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Re: Microbrute Tuning and Pitch Out Voltage
« Reply #3 on: August 28, 2014, 11:42:05 am »
I checked the User manual, it is wrong indeed , sorry about that. MicroBrute Gate Output voltage is 0-10V and not 0-5V.

To drive your 0-5V input you should use an attenuator, or ask the manufacturer in the input can handle 10V.

I'll request an update of the manual.
Bruno
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