issue16

EMUSIC-L Digest                                      Volume 56, Issue 16

This issue's topics:
	
	MIDI ring networks? (5 messages)

Your EMUSIC-L Digest moderator is Joe McMahon .
You may subscribe to EMUSIC-L by sending mail to listserv@american.edu with 
the line "SUB EMUSIC-L your name" as the text.
 
The EMUSIC-L archive is a service of SunSite (sunsite.unc.edu) at the 
University of North Carolina.
------------------------------------------------------------------------
Date:         Tue, 14 Sep 1993 18:00:08 BST
From:         "Steven D. Bramson" 
Subject:      MIDI ring networks?

There must be a number of people out there who are using a MIDI network with a
ring included in the topology.  For example, you have a synth which you use as
a master keyboard and as a tone generator, one or MIDI expanders as additional
tone genrators and a PC/Mac/Amiga/Atari etc. for sequencing.  You want to use
the synth keyboard as input to your computer sequencer and you want the
sequencer to play the same synth as a tone generator.

The above must surely mean you have a ring where the MIDI output of the master
synth is fed back to the MIDI in of the same synth via the computer and
possibly via one or more expanders.

Here are a couple of examples

Synth Out --> In Computer Out --> In Synth Thru --> In Expander

Synth Out --> In Computer Out --> In Expander Thru --> In Synth

I know that some synths have a Local Control Off feature where you can make
the synth ignore input from its own keyboard and only take input from MIDI in.

Here at last are my questions.  If you do not use Local Control Off

1. Does the network lock up resulting in no sound?

2. Do you get a double note when you press a key on the master synth?

3. Is the delay small enough that if you do get a double not you don't hear
it?  (Let's not start a flame war on MIDI delays)

4. Do you get a continuous note when you press a key on the master synth?

5. Does it just work OK?

6. Is it synth/computer/midi interface/sequencer software dependent?


 Steven D Bramson    Data Management Group   JET Joint Undertaking
 Abingdon     Oxfordshire              OX14 3EA     United Kingdom
 E-mail sdb@jet.uk   Voice 0235 465 013           Fax 0235 465 399
------------------------------------------------------------------
 JET is Europe's fusion research project
 Disclaimer: Any views expressed are mine and do not represent those of JET

------------------------------
Date:         Wed, 15 Sep 1993 08:36:00 GMT+0100
From:         Chris Gray 
Subject:      Re: MIDI ring networks?

>There must be a number of people out there who are using a MIDI network with a
>ring included in the topology.  For example, you have a synth which you use as
>a master keyboard and as a tone generator, one or MIDI expanders as additional
>tone genrators and a PC/Mac/Amiga/Atari etc. for sequencing.  You want to use
>the synth keyboard as input to your computer sequencer and you want the
>sequencer to play the same synth as a tone generator.
>
>The above must surely mean you have a ring where the MIDI output of the master
>synth is fed back to the MIDI in of the same synth via the computer and
>possibly via one or more expanders.
>
>Here are a couple of examples
>
>Synth Out --> In Computer Out --> In Synth Thru --> In Expander
>
>Synth Out --> In Computer Out --> In Expander Thru --> In Synth
>
>I know that some synths have a Local Control Off feature where you can make
>the synth ignore input from its own keyboard and only take input from MIDI in.
>
>Here at last are my questions.  If you do not use Local Control Off
>
>1. Does the network lock up resulting in no sound?

No.

>2. Do you get a double note when you press a key on the master synth?

Yes.

>3. Is the delay small enough that if you do get a double not you don't hear
>it?  (Let's not start a flame war on MIDI delays)

If both synth and sequencer had instantaneous reaction times then you wouldn't
be able to hear it.  This is an excellent way to measure the combined
reaction times of your synth and sequencer.  With your background you
should be able to design experiments to work out the separate contributions
of the two components. :>

(Spoilsport.  You know I just love flame wars on MIDI delays).

>4. Do you get a continuous note when you press a key on the master synth?

No, because the synth will (hopefully) not relay the information it
receives on its its In to its Out; you need to use the Thru port to
create that kind of chaos.  (NB some brain-damages boxes with only two
ports have the ``feature'' that the Out is also a Thru).

>5. Does it just work OK?

See 2. above.  This is not a satisfactory way of working.

>6. Is it synth/computer/midi interface/sequencer software dependent?

Very.  See 1-5 above.

> Steven D Bramson    Data Management Group   JET Joint Undertaking
> Abingdon     Oxfordshire              OX14 3EA     United Kingdom
> E-mail sdb@jet.uk   Voice 0235 465 013           Fax 0235 465 399
>------------------------------------------------------------------
> JET is Europe's fusion research project
> Disclaimer: Any views expressed are mine and do not represent those of JET

But who would listen to the views of a mere torus?

__________________________________________________________________________
Chris Gray        cgra@se.alcbel.be         Compu$erve: 100065.2102
   Ignore my broken mailer - the addresses above are the only truth
__________________________________________________________________________

The "soft thru" feature on the sequencer, which when ON, wends from MIDI
OUT a copy of everything received.
                                                - Roland, EP-7 manual

------------------------------
Date:         Wed, 15 Sep 1993 11:09:30 +0200
From:         Kalev Tiits 
Subject:      Re: MIDI ring networks?

Steven D. Bramson writes:



I know that some synths have a Local Control Off feature where you
can make
the synth ignore input from its own keyboard and only take input from
MIDI in.

Here at last are my questions.  If you do not use Local Control Off

1. Does the network lock up resulting in no sound?

2. Do you get a double note when you press a key on the master synth?

3. Is the delay small enough that if you do get a double not you
don't hear
it?  (Let's not start a flame war on MIDI delays)

4. Do you get a continuous note when you press a key on the master
synth?

5. Does it just work OK?

6. Is it synth/computer/midi interface/sequencer software dependent?


in my somewhat limited experience, the answers are:

1. No
2. Yes
3. depends on the synth, generally you dont hear the doubling

(see #5)
4. dont know what you mean exactly, if you press a key continously,
you will get a continous note yeah.

5. No

(the synths ive used make some nasty not-exactly-in-phase effects
when you do this. but then again this might be what you want, it is
not what i want anyway. plus it cuts your polyphony to half of what
it would be otherwise. having said that, some synths might still
sound ok. the ones i tried were some older ensoniq machines) anyways,
i recommend, if you have the local off switch, use it. i dont think
there is any harm trying it out.
6. yes, to an extent (see above).

Kalev Tiits
University of Helsinki, dept of musicology
Helsinki, Finland
kalev@elisir.helsinki.fi

------------------------------
Date:         Wed, 15 Sep 1993 08:28:36 EDT
From:         Bill Fox 
Subject:      Re: MIDI ring networks?

Steven D. Bramson asked about a circular topology.  I'd like to add that
if your keyboard doesn't have local on/off control, most likely your
sequencer does have software thru (echo) control which is another way to
break the circle when appropriate.

Bill Fox

------------------------------
Date:         Wed, 15 Sep 1993 18:38:30 GMT
From:         james lowell noxon 
Subject:      Re: MIDI ring networks?

The MIDI ring newtork is one of the 3 possible classifications that come
from network topology. The other two are buss ( using a patch bay ), and
star ( using a midi merge system ). The ring is the cheapest expandable
network, but it is tricky to use - get organized or get double notes, even
the dreaded MIDI feedback ( messages circulating endlessly - also called
a LAN storm ).

To make a loop network ( ring ), you need a two input midi switcher for each
unit in the loop. The two inputs select between: MIDI out ( data input to the
loop from this location ), MIDI thru ( data passed on from the previous member
of the loop ). The output of the switcher goes to the MIDI in of the next unit.

To use the network, select the unit you wish to enter data from, switch to
MIDI outs on the two switchers on either side of this unit, switch to MIDI thru
on all other units. Now everyone "listens" to this member, and it does'nt play
double notes. You have 'broken' the loop at the point where you are currently
entering data. As you use other members around the loop, you move the 'break'
by always switching to MIDI out on either side of that member, and switching to
MIDI thru elsewhere. When you get to doing overdubs on a sequencer while
syncing the sequencer to the drum machine and playing a controller without
a MIDI thru, ... phew ... yes it is complicated and beyond the scope of an
email newsgroup, - BUT IT CAN BE DONE ! I show in my instructional video and
lectures / workshops - anything that can be done with the equipment involved
can be accomodated with either the loop network or the midi merge system (star
network). The difference is the loop requires careful organization and the
star network costs more ( but you never have to change any switchers again ! ).

--
PJ Noxon - aka - Park James Noxon
president of MIDIMIX - inventor of the midi merge
jnoxon@indiana.edu

------------------------------
End of the EMUSIC-L Digest
******************************