MB808 - i havent Trigger output

MIDIbox SEQ
1

I have some questions about the trigger section in the MB808

 

i have keep the original configuration in the the asm files with the MIDI output port value = 1 like this

When i try to check the DOUT with oscilloscope i don’t see anny voltage .

IT is normal or i need to do something ?

 

 

; Following table allows you to define
;   - the track names (must consist of exactly 6 characters!)
;   - the DOUT shift registers (SR) to which the drum triggers are connected
;     (1-16; 0 disables assignment)
;   - the DOUT pin to which the drum triggers are connected (0-7)
;     Note: since version v1.3 the “real” Dx pin number (D0..D7) has to be specified, in previous releases it was mirrored!
;   - the MIDI output port (0=disabled, 1=Default, 2=Internal, 3=IIC1, 4=IIC2, 5=IIC3, 6=IIC4, 7=Trigger Only)
;   - the AOUT/CV channel to output velocity (1-16, 0=disabled)
;     Note: AOUT module only supports 8 highres channels, but CV outputs can also be realized with DOUTs (see DEFAULT_CV_DOUT* option)
DEFAULT_TRKINFO MACRO
    ;;       Name     SR  Pin MPort AChn
    db  "BD    ",  1,  6,   1,    0 ; Track 1
    db  "SD    ",  1,  5,   1,    0 ; Track 2
    db  "LT/LC ",  1,  4,   1,    0 ; Track 3
    db  "MT/MC ",  1,  3,   1,    0 ; Track 4
    db  "HT/HC ",  1,  2,   1,    0 ; Track 5
    db  "CP    ",  1,  1,   1,    0 ; Track 6
    db  "MA    ",  1,  0,   1,    0 ; Track 7
    db  "RS/CL ",  4,  7,   1,    0 ; Track 8
    db  "CB    ",  4,  6,   1,    0 ; Track 9
    db  "CY    ",  4,  4,   1,    0 ; Track 10
    db  "OH    ",  4,  3,   1,    0 ; Track 11
    db  "CH    ",  4,  2,   1,    0 ; Track 12
    db  "Ext1  ",  0,  0,   1,    0 ; Track 13
    db  "Ext2  ",  0,  0,   1,    0 ; Track 14
    db  "Ext3  ",  0,  0,   1,    0 ; Track 15
    db  "Acc.  ",  7,  0,   7,    0 ; Track 16
    ENDM

 

 

I also read that about the _ Menu Page Selection _ but i can’t change the value of manual page?

 

 

 

Manual: If sequencer playing: position of all tracks will be set to the selected step.
Sequencer not playing: triggers the step of the selected instrument

 

2

When i try to check the DOUT with oscilloscope i don’t see anny voltage .

 

Pulses are very short (only 1 mS) - did you consider this?

 

 

 

I also read that about the _ Menu Page Selection _ but i can’t change the value of manual page?

 

I just checked the Manual page, it works at my side.

Or did you mean something else?

 

Best Regards, Thorsten.

3

Pulses are very short (only 1 mS) - did you consider this?

Yes i understand that is very short

how do you do to see the instrument trigger  led blinking withe the full MB808 ?

I m thinking that i could see the pulse with an oscilloscope no ?

I wanted to check if i have the pulse could you tell me how i can do it ?

 

 

_ Menu Page Selection _

Perhaps i don’t understand how it’s work …

4

how do you do to see the instrument trigger  led blinking withe the full MB808 ?

 

It will blink shortly (will be visible) - so, it would also be a good testing method.

 

 

 

I wanted to check if i have the pulse could you tell me how i can do it ?

 

One thing came in my mind: are you really checking the right 74HC595 pin?

See also this schematic: http://www.ucapps.de/mbhp/mbhp_doutx4.pdf

E.g. in your setup, the bass drum is triggered with the first SR, pin D6, which should be 74HC595 pin #6

For the case that I’ve messed up this: could you please check, if you see a trigger at pin #1 instead?

Or at any other DOUT pin?

 

 

 

Perhaps i don’t understand how it’s work …

 

Start the sequencer, enter the Manual page, press GP1 button.

You will notice that the sequencer always jumps to this step when you are pressing this button.

 

Press GP5 button, the sequencer will jump to this position…

 

Stop the sequencer. 

Press GP1 button - the sequencer will play all instruments which are enabled for this step (you will hear this once the DOUT triggers are working)

 

Best Regards, Thorsten.