150ft midi cable ?

Discussion in 'comp.music.midi' started by Greg, May 26, 2003.

  1. Greg

    Greg Guest

    I need a 150 ft midi cable.... so, I need an amplifier too !
    Does anyone have schematics of that kind of booster ?

    Tks


    Best regards.




    Greg
  2. Mike

    Mike Guest

    "Greg" <crf34@wanadoo.fr> wrote:
    > I need a 150 ft midi cable.... so, I need an amplifier too !
    > Does anyone have schematics of that kind of booster ?


    Another option is to buy a 1-in-many-out MIDI through device.
    Some of them "improves" the signal before passing it on.
    Check with the manufacturers, e.g. Philip Rees.

    Kind regards
    Mikael Hillborg
    MHC Synthesizers and Effects
    http://www.mhc.se/software/plugins/
  3. eMail2Me

    eMail2Me Guest

    Is not MIDI stands for Music Instrument Digital Interface? If so, does this
    mean the data output from any MIDI ports is binary (Can anyone please
    clarify this)? For digital signals and IIRC in theoretically speaking, one
    should be able to propagate any digital signal to its max distant without
    any degredation by maintaining its impedance matched across the medium so
    that there is no drop in voltage. Thus, no current passing through the
    medium which implies no generation of electromagnetic fields across the
    medium of propagation that will cause interference to the digital signals.
    For a copper medium, a standard cat-5 twisted pair cable (not expensive)
    should be able to do the job. If the data at the MIDI port is analog, then
    it's a different story.


    Mike wrote:

    > "Greg" <crf34@wanadoo.fr> wrote:
    >> I need a 150 ft midi cable.... so, I need an amplifier too !
    >> Does anyone have schematics of that kind of booster ?

    >
    > Another option is to buy a 1-in-many-out MIDI through device.
    > Some of them "improves" the signal before passing it on.
    > Check with the manufacturers, e.g. Philip Rees.
    >
    > Kind regards
    > Mikael Hillborg
    > MHC Synthesizers and Effects
    > http://www.mhc.se/software/plugins/
  4. eMail2Me wrote:

    >Is not MIDI stands for Music Instrument Digital Interface? If so, does this
    >mean the data output from any MIDI ports is binary (Can anyone please
    >clarify this)? For digital signals and IIRC in theoretically speaking, one
    >should be able to propagate any digital signal to its max distant without
    >any degredation by maintaining its impedance matched across the medium so
    >that there is no drop in voltage. Thus, no current passing through the
    >medium which implies no generation of electromagnetic fields across the
    >medium of propagation that will cause interference to the digital signals.
    >For a copper medium, a standard cat-5 twisted pair cable (not expensive)
    >should be able to do the job. If the data at the MIDI port is analog, then
    >it's a different story.


    The physical layer of MIDI data transmission is certainly digital, but it
    is a current loop interface rather than a voltage interface. This means
    that the transmission line effects that benefit from impedance matching
    don't apply.

    The usual problem with long MIDI lines is the accumulated line capacitance
    that has to be charged or discharged each time the line changes state.
    This has the effect of slowing those transitions and, in the extreme,
    can result in receiver bit errors.

    A solution is to "regenerate" the signal every 50 feet or so with a 1 X 1
    "thru" box. Here's a schematic of just such a device.


    +5V +5V DIN
    +5V 270 | | 220 +-+
    DIN | +--\/\/\/-+ |\ +-\/\/\/--|4|
    +-+ 220 +-------+ | | \ | |
    |4|--\/\/\/--|2 8 6|-+------------| \---\/\/\/--|5|
    | | | 6N138 | | / 220 | |
    |5|----------|3 5|-+ 7407| / +--|2|
    | | +-------+ | |/ | +-+
    |2| COM COM
    +-+

    --
    ========================================================================
    Michael Kesti | "And like, one and one don't make
    | two, one and one make one."
    mkesti@gv.net | - The Who, Bargain
  5. Mike

    Mike Guest

    "eMail2Me" <SPAMMERs.eMail2Me@False.Alarmed.HomeLinux.net> wrote:
    > Is not MIDI stands for Music Instrument Digital Interface? If so, does this
    > mean the data output from any MIDI ports is binary (Can anyone please
    > clarify this)? For digital signals and IIRC in theoretically speaking, one
    > should be able to propagate any digital signal to its max distant without
    > any degredation by maintaining its impedance matched across the medium so
    > that there is no drop in voltage. Thus, no current passing through the
    > medium which implies no generation of electromagnetic fields across the
    > medium of propagation that will cause interference to the digital signals.
    > For a copper medium, a standard cat-5 twisted pair cable (not expensive)
    > should be able to do the job. If the data at the MIDI port is analog, then
    > it's a different story.


    The spec puts requirements on the rise and fall times of the digital signal
    (around 2 microseconds I believe), for proper and reasonably error free operation.
    The longer cables you use, the more capacity they will have and the bigger rise/fall
    time you will get. That's why long cables should be avoided and that's why you
    might have to feed the signal through a reshaper, such as a computer, a keyboard
    which does a software copy or any other *active* device.

    Mikael Hillborg
    MHC Synthesizers and Effects
    http://www.mhc.se/software/plugins/
  6. Greg

    Greg Guest

    A normal midi cable, without amplification, can't be longer than 40 or 45 ft
    ..
    For a 150 Ft cable, I must boost the signal.


    "Mike" <Mike@nospam.com> a écrit dans le message de
    news:yDpAa.11455$dP1.21923@newsc.telia.net...
    > "eMail2Me" <SPAMMERs.eMail2Me@False.Alarmed.HomeLinux.net> wrote:
    > > Is not MIDI stands for Music Instrument Digital Interface? If so, does

    this
    > > mean the data output from any MIDI ports is binary (Can anyone please
    > > clarify this)? For digital signals and IIRC in theoretically speaking,

    one
    > > should be able to propagate any digital signal to its max distant

    without
    > > any degredation by maintaining its impedance matched across the medium

    so
    > > that there is no drop in voltage. Thus, no current passing through the
    > > medium which implies no generation of electromagnetic fields across the
    > > medium of propagation that will cause interference to the digital

    signals.
    > > For a copper medium, a standard cat-5 twisted pair cable (not expensive)
    > > should be able to do the job. If the data at the MIDI port is analog,

    then
    > > it's a different story.

    >
    > The spec puts requirements on the rise and fall times of the digital

    signal
    > (around 2 microseconds I believe), for proper and reasonably error free

    operation.
    > The longer cables you use, the more capacity they will have and the bigger

    rise/fall
    > time you will get. That's why long cables should be avoided and that's why

    you
    > might have to feed the signal through a reshaper, such as a computer, a

    keyboard
    > which does a software copy or any other *active* device.
    >
    > Mikael Hillborg
    > MHC Synthesizers and Effects
    > http://www.mhc.se/software/plugins/
    >
    >
    >
    >
  7. Mike

    Mike Guest

    "Greg" <crf34@wanadoo.fr> wrote:
    > A normal midi cable, without amplification, can't be longer than 40 or 45 ft
    > .
    > For a 150 Ft cable, I must boost the signal.
    >


    Boosting only won't help since the problem is the rise and fall (edges) of the signal.
    Thus you need to use a thru box or any other active device, which reshapes the signal
    rather than just amplifying it.

    --
    Kind regards
    Mikael Hillborg
    MHC Synthesizers and Effects
    http://www.mhc.se/software/plugins/
  8. JB Seattle

    JB Seattle Guest

    That is correct, but then you already told him once before--some people
    won't read what they do not want to hear.
    JB
    "Mike" <Mike@nospam.com> wrote in message
    news:OwtAa.11522$dP1.21950@newsc.telia.net...
    > "Greg" <crf34@wanadoo.fr> wrote:
    > > A normal midi cable, without amplification, can't be longer than 40 or

    45 ft
    > > .
    > > For a 150 Ft cable, I must boost the signal.
    > >

    >
    > Boosting only won't help since the problem is the rise and fall (edges) of

    the signal.
    > Thus you need to use a thru box or any other active device, which reshapes

    the signal
    > rather than just amplifying it.
    >
    > --
    > Kind regards
    > Mikael Hillborg
    > MHC Synthesizers and Effects
    > http://www.mhc.se/software/plugins/
    >
    >
    >
    >
    >
  9. >Is not MIDI stands for Music Instrument Digital Interface? If so, does this
    >mean the data output from any MIDI ports is binary (Can anyone please
    >clarify this)? For digital signals and IIRC in theoretically speaking, one
    >should be able to propagate any digital signal to its max distant without
    >any degredation by maintaining its impedance matched across the medium so
    >that there is no drop in voltage. Thus, no current passing through the
    >medium which implies no generation of electromagnetic fields across the
    >medium of propagation that will cause interference to the digital signals.
    >For a copper medium, a standard cat-5 twisted pair cable (not expensive)
    >should be able to do the job. If the data at the MIDI port is analog, then
    >it's a different story.


    It's a current loop.

    CubaseFAQ page www.laurencepayne.co.uk/CubaseFAQ.htm

  10. >That is correct, but then you already told him once before--some people
    >won't read what they do not want to hear.


    I've seen a system that converts midi to a signal suitable for
    transmission down a balanced microphone cable, then converts it back
    at the other end. If this is more than a one-off application, it
    could be worth investigating.

    Has he told us what he's trying to do?

    CubaseFAQ page www.laurencepayne.co.uk/CubaseFAQ.htm
  11. In article <0349dvciddj4soep6jacm8be2pebja09oc@4ax.com>,
    Laurence Payne <l@laurenceDELETEpayne.freeserve.co.uk> wrote:

    >I've seen a system that converts midi to a signal suitable for
    >transmission down a balanced microphone cable, then converts it back
    >at the other end. If this is more than a one-off application, it
    >could be worth investigating.


    That is what I have been making since 1985:
    http://www.hinton.demon.co.uk/midiprods.html

    Our system can drive 1km of audio grade cable and is used by large
    theatres, major tours and theme park installations.

    The 15m limitation of MIDI is part of its spec and is a consequence of both
    having protection against blowing up two outputs connected together and the
    use of optoisolators to avoid groundloops.
    It is not a question of boosting the signal, it has to be guaranteed to
    work with all products meeting the MIDI spec (however marginally).
  12. M.O.T.E.

    M.O.T.E. New Member

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  13. Dave Borr

    Dave Borr Guest

    Graham Hinton <hitman@spammer.deathsquad.com> wrote:

    > In article <0349dvciddj4soep6jacm8be2pebja09oc@4ax.com>,
    > Laurence Payne <l@laurenceDELETEpayne.freeserve.co.uk> wrote:
    >
    > >I've seen a system that converts midi to a signal suitable for
    > >transmission down a balanced microphone cable, then converts it back
    > >at the other end. If this is more than a one-off application, it
    > >could be worth investigating.

    >
    > That is what I have been making since 1985:
    > http://www.hinton.demon.co.uk/midiprods.html
    >
    > Our system can drive 1km of audio grade cable and is used by large
    > theatres, major tours and theme park installations.
    >
    > The 15m limitation of MIDI is part of its spec and is a consequence of both
    > having protection against blowing up two outputs connected together and the
    > use of optoisolators to avoid groundloops.
    > It is not a question of boosting the signal, it has to be guaranteed to
    > work with all products meeting the MIDI spec (however marginally).


    Graham (or anyone else):

    Would such an item allow use of a wireless mic system to provide
    wireless transmission of MIDI data in live performance?

    Or simpler, are there such things as wireless transmitters/receivers for
    use directly with MIDI data?

    Purpose: to play an over the shoulder keyboard controller which
    transmits MIDI data to on-stage synth units, alowing one to maintain
    mobile freedom to move around a venue during performance.

    If so, please suggest manufacturers, web sites, or such to help me
    review.

    Dave
  14. In article <1fvsn90.58da3i1gdwnzsN%dborr@tic.bisman.com>,
    dborr@tic.bisman.com (Dave Borr) wrote:

    >Graham (or anyone else):
    >
    >Would such an item allow use of a wireless mic system to provide
    >wireless transmission of MIDI data in live performance?


    No, because the wireless microphone channel only has an audio bandwidth and
    MIDI needs more than double that.
    In might be possible to reshape or use data compression on the signal, but
    the price for that is delay and errors.
    With my Long Haul system I absolutely guarantee a worst case delay of 11
    microseconds over 1km of cable delivering a perfectly reconstituted MIDI
    signal, i.e. it is transparent in practically all applications. You are not
    going to get that sort of performance out of a radio link, especially a
    microphone one.
    Also my system is not mic level signals, it just uses existing cabling in
    installations.


    >Or simpler, are there such things as wireless transmitters/receivers for
    >use directly with MIDI data?
    >
    >Purpose: to play an over the shoulder keyboard controller which
    >transmits MIDI data to on-stage synth units, alowing one to maintain
    >mobile freedom to move around a venue during performance.
    >
    >If so, please suggest manufacturers, web sites, or such to help me
    >review.


    There have been some offerings in the past that have failed miserably due
    to the reasons already stated.

    There was a prototype Bluetooth device shown (not working) at NAMM the
    other year by M Audio and mentioned in the current SOS. I quote the
    article: "I'm not sure if I'd like to do a live gig based on this
    technology, any more than I'd like the steering wheel to be connected to
    the wheels of my car by Bluetooth right now."
    Quite.

    This sort of device is a chimera, you can sort of imagine what it would be
    like, but if you find one it doesn't work like you hoped.
  15. In article <1fvsn90.58da3i1gdwnzsN%dborr@tic.bisman.com>,
    dborr@tic.bisman.com (Dave Borr) wrote:

    >Graham (or anyone else):
    >
    >Would such an item allow use of a wireless mic system to provide
    >wireless transmission of MIDI data in live performance?


    No, because the wireless microphone channel only has an audio bandwidth and
    MIDI needs more than double that.
    In might be possible to reshape or use data compression on the signal, but
    the price for that is delay and errors.
    With my Long Haul system I absolutely guarantee a worst case delay of 11
    microseconds over 1km of cable delivering a perfectly reconstituted MIDI
    signal, i.e. it is transparent in practically all applications. You are not
    going to get that sort of performance out of a radio link, especially a
    microphone one.
    Also my system is not mic level signals, it just uses existing cabling in
    installations.


    >Or simpler, are there such things as wireless transmitters/receivers for
    >use directly with MIDI data?
    >
    >Purpose: to play an over the shoulder keyboard controller which
    >transmits MIDI data to on-stage synth units, alowing one to maintain
    >mobile freedom to move around a venue during performance.
    >
    >If so, please suggest manufacturers, web sites, or such to help me
    >review.


    There have been some offerings in the past that have failed miserably due
    to the reasons already stated.

    There was a prototype Bluetooth device shown (not working) at NAMM the
    other year by M Audio and mentioned in the current SOS. I quote the
    article: "I'm not sure if I'd like to do a live gig based on this
    technology, any more than I'd like the steering wheel to be connected to
    the wheels of my car by Bluetooth right now."
    Quite.

    This sort of device is a chimera, you can sort of imagine what it would be
    like, but if you find one it doesn't work like you hoped.
  16. Greg

    Greg Guest

    I'm happy : Thank You.
    With your help - "That is correct, but then you already told him once
    before--some people
    won't read what they do not want to hear." - I finally understood.

    It was kind to be so nice. :)

    By the way, I'll use a pair of converters midi/RS485/midi.

    Thank's again .


    GReg


    "JB Seattle" <shnoozle8@hotmail.com> a écrit dans le message de
    news:LMMAa.19218$Io.1704592@newsread2.prod.itd.earthlink.net...
    > That is correct, but then you already told him once before--some people
    > won't read what they do not want to hear.
    > JB
    > "Mike" <Mike@nospam.com> wrote in message
    > news:OwtAa.11522$dP1.21950@newsc.telia.net...
    > > "Greg" <crf34@wanadoo.fr> wrote:
    > > > A normal midi cable, without amplification, can't be longer than 40 or

    > 45 ft
    > > > .
    > > > For a 150 Ft cable, I must boost the signal.
    > > >

    > >
    > > Boosting only won't help since the problem is the rise and fall (edges)

    of
    > the signal.
    > > Thus you need to use a thru box or any other active device, which

    reshapes
    > the signal
    > > rather than just amplifying it.
    > >
    > > --
    > > Kind regards
    > > Mikael Hillborg
    > > MHC Synthesizers and Effects
    > > http://www.mhc.se/software/plugins/
    > >
    > >
    > >
    > >
    > >

    >
    >
  17. Guest

    Guest Guest

    Graham Hinton <hitman@spammer.deathsquad.com> schreef in berichtnieuws
    BAFE82389668D8704@0.0.0.0...
    > In article <1fvsn90.58da3i1gdwnzsN%dborr@tic.bisman.com>,
    > dborr@tic.bisman.com (Dave Borr) wrote:
    >
    > >Graham (or anyone else):
    > >
    > >Would such an item allow use of a wireless mic system to provide
    > >wireless transmission of MIDI data in live performance?

    >
    > No, because the wireless microphone channel only has an audio bandwidth

    and
    > MIDI needs more than double that.
    > In might be possible to reshape or use data compression on the signal, but
    > the price for that is delay and errors.
    > With my Long Haul system I absolutely guarantee a worst case delay of 11
    > microseconds over 1km of cable delivering a perfectly reconstituted MIDI
    > signal, i.e. it is transparent in practically all applications. You are

    not
    > going to get that sort of performance out of a radio link, especially a
    > microphone one.
    > Also my system is not mic level signals, it just uses existing cabling in
    > installations.
    >
    >
    > >Or simpler, are there such things as wireless transmitters/receivers for
    > >use directly with MIDI data?
    > >
    > >Purpose: to play an over the shoulder keyboard controller which
    > >transmits MIDI data to on-stage synth units, alowing one to maintain
    > >mobile freedom to move around a venue during performance.
    > >
    > >If so, please suggest manufacturers, web sites, or such to help me
    > >review.

    >
    > There have been some offerings in the past that have failed miserably due
    > to the reasons already stated.
    >
    > There was a prototype Bluetooth device shown (not working) at NAMM the
    > other year by M Audio and mentioned in the current SOS. I quote the
    > article: "I'm not sure if I'd like to do a live gig based on this
    > technology, any more than I'd like the steering wheel to be connected to
    > the wheels of my car by Bluetooth right now."
    > Quite.
    >
    > This sort of device is a chimera, you can sort of imagine what it would be
    > like, but if you find one it doesn't work like you hoped.
    >
    > Yes, there is a wireless midisystem that works without any delays and

    already is in use by one or more of my colleges in germany whoom walk around
    whit a wireless accordeon and use it whit a master switchtboard transmitted
    to a workstation positioned somewereelse, unfortunatly i don,t know the name
    of the company whp builds the sets but i know its german made ( costs about
    8to 10000 euro,s ) good luck whit your surch.
    >
  18. Note Jam

    Note Jam Guest

    Midi is sent at a baud rate of 31250. Thats much faster than audio amps and
    mics upper frequency limit, which usually is 20,000 or less.

    Might possibly drive a large bright infra-red led from your synth, and then
    have a circuit with a infra-red photo transistor as input to your midi devices.


    If this worked, you would have to limit yourself to what ever range was
    allowed, and probably remain positioned in a certain direction, but could at
    least move around.

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