Odd midi transpose bug? Not! -just base 12 numbers

OS_CE Forums Octopus Support Odd midi transpose bug? Not! -just base 12 numbers

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    I’ve just had at my octopus sequencer for one night and I’m perplexed with an odd Midi note problem.

    When I program a track to output on one midi note; eg. A1 = 33, the octopus sequencer outputs a note that’s 3 semitones higher, eg for this case the note C2 = 36 would be produced.

    I’m using midi-ox to monitor the octopus’ output note value. I’ve checked my midi input hardware (emu 1212m) & midi-ox with another midi keyboard to make sure that midi-ox and the input hardware isn’t somehow transposing the note – it’s not.

    When I check the note’s pitch by pressing down the track key and moving the "pitch" knob I get 1 = red, 2 = red , 3 = orange which should equal 33.

    The note isn’t transposed on the octopus; i.e. when I zoom in on the note, transpose is set to 0.

    I’ve tried resetting the octopus and get the same behavior.

    Could anyone please help to shed some light on this issue?

    many thanks,

    P.S. I’m using OS 1.6.2

    Post edited by: trance4ever, at: 2010/08/04 06:51

    Post edited by: trance4ever, at: 2010/08/05 05:04

    zahir manek

    Do you have Force to Scale on?


    Thanks for the reply Stikey, I checked and "Force scale" was off.

    I figured it out….

    The first thing I noticed is that when you hold down the track selector button and turn the pitch knob the progression of the red and green LED’s corresponds to a base 12 numbering system.

    Hence LED 1 = red
    LED 2 = red
    LED 3 = orange

    means the number 30 in base 12 or 36 base 10 which is the right midi note number for C2 (or C3 depending on which MIDI standard you use).

    If LED 3 was red instead of orange and LED 4 was green that would be 31 base 12 or 37 base 10.

    So…. why base 12? Hmmm…. there are 12 semitones in an octave.

    Then I noticed that the semitones of the C major scale are silk screened across the top of the 10 x 16 grid.

    This allows the note names to be read out directly. The green (or orange) LED is the note name and the number of red (+orange) LED’s lit on the left is the octave number of the note. So 3 red LED’s plus a green LED under the "D" is D3.

    So far I haven’t found a description of this in the manual but I assume it’s there somewhere.


    Post edited by: trance4ever, at: 2010/08/05 05:17

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