Re: [Ensoniq-VFX-SD] Beware cheap chinese USB MID I cables on ebay...
2008-06-21 by Claus
Hi Steve :)
I´ve been using a Winman 1x1 (ISA back then!) with no problems. Midiman BiPort 2x4s (COM port) on Win98se with NO problems. For the last year or so, a MidiSport 8x8 (USB on 98se(!!) is running. No problem either. I've also tried the MIDI I/O on the Evolution UC33e controller and the MIDI I/O on a Terratec Phase 22. All working.
So I'm really wondering what Your problem might be. Maybe I'm wrong, but to my knowledge, VFXs don't use running status. Roland does, as one of the only ones getting to my mind from back then.
To me it really sounds like a 'bad' USB port or something along that line. Which might include bad drivers. The BiPort 2x4s as an example runs way better with v1.02 than the newest avaiable drivers (1.05 I think, allthough discontinued). Have You tried that? It MIGHT help. Else I really would suggest the 8x8s (or similar), since it: Brings LOTS of I/O, works as a MIDI-patchbay. AND can be used without the computer :)) (OK, pricey, but really nice!)
One last (SIMPLE!) suggestion, as I had this problem once: Have You tried spraying the MIDI I/Os on the VFX with elctronic-cleaner? That MIGHT help too. You're on XP?
Regards,
- Claus, DK
----Original Message-----
From: steve@...
Sent: Friday, June 20, 2008 7:47 PM -07:00
To: Ensoniq-VFX-SD@yahoogroups.com
Subject: [Ensoniq-VFX-SD] Beware cheap chinese USB MIDI cables on ebay...
This is a heads up to all of you. If you know of a better forum I
should be posting this in, let me know.
Having recently put some softsynth software on my mac laptop, I wanted
a usb - midi interface that I could just put in my laptop bag and have
with me. There are a bunch of cheap, 1x1 usb midi adapters available
on ebay for around $20 after shipping. I could not find much
information on whether these worked well or not, using google. So I
thought I'd try one.
I hooked it up to my VFX-SD and things were NOT working well. I tried
it with my Macbook laptop and with my windows XP desktop machine. In
both cases, the symptoms were the same. A single note would play
fine, but chords would not, no matter how much time between pressing
each note. And there were stuck notes, etc.
So the short story is: you may get even less than you pay for if you
try to use one of these with a VFX.
I looked at the output with Midi-Ox, and I think I may have a clue to
the problem. The rest of this message is pretty much pure speculation.
It looks like this device does not handle running status correctly.
And at least my VFX-SD seems to send running status whenever it can.
Running status is a midi feature that's been around from the
begining of midi. Status bytes have the high bit set (decimal
value is greater than 127), other bytes don't. For example, a
note on message looks like A0 45 40 (in hexadecimal). A0 is a
status byte that says "this message is a NOTE ON message for
midi channel 1." 45 is the note number, and 40 is the
velocity. If more note on messages need to be sent for
channel 1, the sender is allowed to send just more note
number, velocity byte pairs, without sending the initial byte,
so: A0 45 40 47 42 would be two note on messages on midi
channel 1, one for note 45 velocity of 40, one for note 47
velocity of 42.
This midi interface doesn't seem to react to anything unless there's a
status byte. So, Note-On, Note-off, Note-On, Note-off works, but
Note-On, Note-On, Note-off, Note-off doesn't.
I've heard that these interfaces are rip-offs of the M-Audio midisport
uno; I found this info in the linux alpha drivers section:
- usb-audio: work around broken M-Audio MidiSport Uno firmware
The firmware of the M-Audio USB Uno MIDI Interface has, at least in
hardware revision 1.25, a bug that garbles its USB output. When it
receives a Note On MIDI message that uses running status, the resulting
USB MIDI packet has a wrong CIN (4 instead of 9) and a wrong length
(2 bytes, the status byte is still missing).
This patch adds a workaround to track the CINs and the MIDI messages of
received USB MIDI packets to detect whether a packet with CIN 4 is a
correct SysEx packet or a buggy running status packet.
That suggests that this is probably a bug-for-bug-compatible clone,
and that a workaround is proably already in the other platforms'
USB-MIDI drivers, if only they could be convinced to see this device
as a midisport uno. :-(
Anyway, buyer beware!
--> Steve
--
Steve Wahl steve@...
One day, the light bulb in the fridge burnt out, and I thought to myself,
"At least now I know it's off when the door's closed... Or do I?"