[LAU] Advice: solution to hookk up several USB-MIDI devices

[David Kastrup]

"Jeanette C." <julien at mail.upb.de> writes:

> Hey hey,
> I have several keyboards now, which come with their built-in USB-MIDI
> interface (four to be precise) and I have three more synths that need
> to be connected to MIDI. For the latter I use USB-MIDI adapter
> cables. Alas, I also have other USB devices, which need to be
> connected, not least my braille display.
>
> So, what would be the cheapest/best alternative to hook up all those
> MIDI devices? A bigger USB-hub? Is it possible to have more than four
> ports on a hub anyway?
>
> Due to technical restrictions MIDI-chaining is no option.
>
> All my devices have standard 5pin MIDI DIN sockets, so some kind of
> USB-MIDI interface would be possible. Only two of the synth need to be
> connected as inuts, all the other would only receive output (being
> modules).
>
> What would be viable and inexpensive options to get all these device
> connected to the computer?

I use a Roland UM-4 myself which hooks up 4 Midi devices (actually, 4in,
4out) to one USB port (full-speed, so 12Mbps, USB1.1 speeds).  Those are
reasonably cheap to get if you can find them on Ebay.  If you want to
hook up several ones of those via a USB hub, make sure that this hub has
a separate "Transaction translator" per port so that a USB1.1
transaction from one Midi interface does not keep other transactions
from happening: the 12Mbps limitation should only be per Midi interface,
not per aggregating hub which can talk at 480Mbps to the computer.  That
way you keep latencies limited.

I think that 8-fold Midi interfaces are rather rare, so you are likely
best off looking for the 4-fold ones.

Do not use the cheap Chinese Midi interfaces with a violin clef printed
on them: they garble SysEx messages.  I am not sure they are even "full
speed".

-- 
David Kastrup