Emu XL-7 & MP-7 User's Group

On 12/5/02 12:09 PM, "jesse_medway" <medway808@...> wrote:

> That was a great explaination.  I have everything setup
> as you described.  I have a midi keyboard controller hooked
> up to the mp-7 for input and this works fine controlling
> my external devices whent the channel is set to ext.
> 
> Not sure if this helps but the only time I can get the
> pads to work (other than setting transmit to on) is if
> I select either multi a or multi b as the channel.
> Of course that means its sending on all channels though
> and not what I want.  Any ideas on why this setting works
> and a single channel doesnt?
> 
> Thanks
> 
> Jesse
> 

Lets see if we can get to the bottom of this.

First I am running the most recent OS so if your not that might be a reason
for any discrepancy.

Also just to make sure we are both saying the same thing, when you put a
track in MultA or MultiB the pads do not transmit on all MIDI channels on
that MIDI OUT.  What it does is send out on the channel that corresponds to
the currently active (shown) channel when you bring up the PRESET status
screen (button PRESET in the MIXER/VIEW area).

This part is definitely one of the more arcane parts of the XX-7 and I
believe it has undergone a good deal of changes since OS 1.0.  I will try to
explain how it works based on my experience.

Normally there is a relationship between a track and one internal synth
channel.  By default this is track-1 -> 01A, track-2 -> 02A and so on.  Even
when you assign a track to EXT it still retains this coupling, though the
internal channel no longer receives any MIDI.

You can start getting a flavor for this if you assign say 05A to track-1.
If you are in the PATTERN view mode and you use TRACK/CHANNEL to move to
another track, say track-2, and you switch over to PRESET view mode you will
see channel 02A be displayed (this is because track-2 by default was set to
02A).  Switch back to PATTERN view and go back to track-1 and switch again
to PRESET view and you will see channel 05A displayed because that is what
track-1 is set to.

What is happening here is that the XX-7 is trying to keep the currently
active internal synthesizer channel (which is called the "Basic Channel")
aligned with what a track is setup to control.  Normally since the
relationship is one-to-one you don't notice this sort of behavior.  But as
can be seen from the example it does exist.

Where it gets really weird is when a track is set to MultiA or MultiB.
since potentially the track can now control any of sixteen different
channels the above "channel tie-in" no longer really makes any sense.  What
channel would it change the basic channel to?  So it does nothing and leave
the basic channel (the channel shown in the PRESET view) where it last was
before you went to that track.

If you try this yourself you can pretty much cause a track set to MultiA to
play any of the internal A-channels simply by switching over to PRESET view,
changing the active (Basic) channel and switching back.

This operation occurs even when a track is set to EXT (MultiA EXT/BOTH or
MultiB EXT/BOTH).

So if you are in the habit of selecting the external MIDI device channel
from the PRESET view screen and not the PATTERN-EDIT Channel Assign menu you
will get very inconsistent results.  Here is an example.

In EDIT-PATTERN track assign you set Track-1 to 10A, EXT so you can control
your external MIDI module on output A, MIDI channel 10.  You switch to
PATTERN VIEW, select Track-1 and sure enough the pads are playing you
external synth on channel 10, as you had hoped.  You switch to PRESET view
and notice channel 10A is selected there as well.  Pretty much all as
expected.

Later you decide that you really want Track-1 assigned to external MIDI 05A.
Your in PATTERN view and select Track-1.  You switch to PRESET view, use the
data entry wheel or the TRACK/CHANNEL buttons to select channel 05A because
that is the one you want to have the track control.  You audition by playing
the pads and... nothing.  No sound is heard on the external synth.  Why?

If you were to switch back to PATTERN view you would find, to your surprise
that Track-5 is now displayed.  You grumble, change it back to Track-1,
making a note to yourself that the XX-7 sure is flakey, switch back to
PRESET view and... channel 10A again!!!

I think it is pretty clear what is happening here.  The PRESET view active
channel, the so called Basic channel, is changing when you change tracks and
the track is changing when you change the basic channel.  the XX-7 is
working overtime to kept things this way and it is not what you expect.

Now there is an exception to all of this behavior, a way you can set a
track's active channel from the PRESET view and that is when a track is
assigned to MultiA or MultiB.  Under these conditions when you change to
such a track in the PATTERN view the Basic channel does not change from its
most recent setting (which is usually what it was set to according to the
track before or after depending on the direction you came to the current
track from).  Likewise if you select a track with its assign set to MultiA
or MultiB in the PATTERN view, switch to the PRESET view *you can freely
choose which channel you want to control by the pads simply by changing the
current, active channel.

There is a consistent inner logic to all of this so it is not buggy or
designed poorly.  it just is a very complex problem that has be solved in
the way described.  It works very well most of the time but things can get a
bit strange if you deviate from the "normal" usage.

The single most important thing to remember is that the Basic channel is
always determined by what the currently active channel in the PRESET view.
When you change channels here you are changing the basic channel.  Most of
the time this will have the side effect of also changing the active track,
and if the track changed to has a different setting for EXT then you had on
the track you thought you were on you will not have the pads sending MIDI to
an external device as you thought it should.


drk

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