Tuesday, December 30, 2008

Statescape: Idaho

I've got a new Statescape up.  Actually two... kind of.

Saturday, December 20, 2008

MIDI Manufacturer IDs

In the MIDI standard for system exclusive ("sysex") messages, one of the information bytes in the header is an ID number that specifies the manufacturer who defined the particular sysex format. Since each manufacturer is free to define their own sysex formats, the manufacturer ID is necessary so that a synth from one manufacturer won't accidentally respond to a sysex meant for a synth from another manufacturer if they coincidentally happen to use the same model number fields. Manufacturer IDs are handed out by the MIDI Manufacturers' Association, which is also the body responsible for maintaining the MIDI protocol standard. Any manufacturer that wishes to define its own sysex messages needs to apply to the MMA for an ID.

Now, in the original MIDI standard, the manufacturer was defined as one byte long. Allowing for the fact that the high bit in any data byte in any MIDI message must be 0 (in order to distinguish it from a command byte, which always has a high bit of 1), that leaves a usable range of numbers of 00-7F hexadecimal, or 0-127 decimal. Long ago, in the original 1983 standard, the MIDI principals (which at the time were Sequential Circuits and Roland) decided to divide the manufacturer IDs into four groups, to be assigned to manufacturers on a geographic basis:

  • 01 to 1F for American manufacturers (00 was reserved, which I'll get to in a bit)
  • 20 to 3F for European manufacturers
  • 40 to 5F for Japanese manufacturers
  • 60 to 7F were reserved for future use (Some of these have since been assigned for certain special purposes, such as the MIDI Sample Dump Standard)

In the original specification, published by Sequential in the January 1984 version of "The Complete SCI MIDI", these manufacturers were assigned:

American group:

01 Sequential
02 Big Briar
03 Octave/Plateau
04 Moog Music
05 Passport Designs
06 Lexicon
10 Oberheim

European group:

20 Bon Tempi

Japanese group:

40 Kawai
41 Roland
42 Korg
43 Yamaha

Sequential received ID #01 as befitting its status as co-originator of the MIDI standard, along with Roland, which was given the "first" number in the Japanese group. (I don't know why Kawai was given 40; it may have been the case that 20 and 40 were reserved at first, as 00 was, and then un-reserved and assigned later.)

A few things to note from that list. Both Moog Music and Big Briar are assigned IDs. At the time this list was issued, in 1984, Moog Music was the original New York company, owned at the time by Norlin (I think; it was about this time that Norlin broke up), while Big Briar was Bob Moog's company in North Carolina (he had been gone from Moog Music for a number of years at this point). As most of you know, the Moog Music that exists now is actually Big Briar renamed; the original Moog Music has long since folded. So I got curious as to which ID Moog is using now. Turns out the current production Voyager uses 04, the original Moog Music ID, and presumably 02 is no longer in use. The MMA's rules today state that a manufacturer must renew their ID each year, or it can be reassigned (much like Internet domain names). However, I doubt that the MMA will reassign 02, even if Moog is no longer renewing it.

Some of you may be wondering now who those other companies in the American and European groups are. Other than Moog/Big Briar and Lexicon, they are all gone from the music industry now. Sequential you know about, the creator of the mighty Prophet-5 and the co-inventor of MIDI. Oberheim is another familiar name to synth perfomers. Octave/Plateau had an interesting run in the '80s; they created what was probably the first rackmount synth, the Voyetra-8, with a remote keyboard that connected to it via a (non-MIDI) control bus. A couple of years later, they introduced the first computer-based sequencer software, which was also called Voyetra, and at that time they changed the company name to Voyetra. This was a very popular package from 1986 up until about 1992, when competition overcame it.

Passport Designs was also a music software company, coinciding with the MIDI era. Like Voyetra, they marketed a sequencer package, called Trax, that was popular in the early days of computer sequencing. They are probably best known for Alchemy, a sample librarian marketed in the 1990s. They were bought out and the existing product line discontinued in 1998. SIEL was an Italian synth manufacturer of some note, one of the two most successful of the 1980s European manufacturers (along with Crumar). They were bought out by Roland in 1987. Bon Tempi was a European maker of combo organs and string machines. They are still in business, but no longer manufacture any keyboard instruments other than some toys. It's curious that they were one of the first to get a manufacturer ID, since I don't think they ever marketed a product that used MIDI.

Despite the demise of these companies, the field of products that use MIDI has expanded dramatically since that 1984 specification. At the time, it was anticipated that only a few dozen manufacturers would ever request or need IDs. But a funny thing happened on the way to the 21st century: the MIDI-using synth field grew dramatically with the advent of soft synths and plug-ins, plus there was an unanticipated explosion in the number of non-synthesizer applications of MIDI. It's common now to find the protocol in use controlling not only studio effects and pipe organs, but also totally non-musical applications such as video editors and light show controllers. By 1990, the pool of available IDs was running out. So the MMA created an "escape hatch": They redefined the manufacturer ID standard to state that an ID byte of 00 indicates that the following two bytes constitute an extended ID field. This opened up another 16,384 ID numbers. They retained the convention of the geographical groupings: the numbers from 00 00 00 to 00 1F 7F are the American group, the 00 20 00 to 00 3F 7F group is the European group, and the 00 40 00 to 00 5F 7F group is the Japanese group. The group from 00 60 00 to 00 7F 7F is apparently going to be a new Asian (China/Russia/Korea/India et al) group, but I don't think any of those have been assigned yet.

There's a list on the MMA's Web site of the most recently assigned IDs (not updated in about a year, unfortunately), and there are some interesting names that pop up. I wonder why National Semiconductor and U.S. Robotics need MIDI IDs? Nvidia (manufacturer of computer video cards) appears, as does supercomputer maker Silicon Graphics (I didn't realize they were still in business). Some old-school names in the professional audio business appear: Electro-Voice, Shure, Otari. Is someone designing MIDI-controlled microphones and loudspeakers? ID 00 01 51 is assigned to Research in Motion, the Blackberry maker. Can you remotely control your Blackberry via MIDI? If so, why? There's a few sad notes too: among the IDs marked "relinquished" is 00 20 50, which belonged to Hartmann GmbH, maker of the brilliant but ill-fated Neuron.

Anyway, what prompted all this was this posting on Matrixsynth, which points out that Dave Smith Instruments is using ID 01, which was Sequential's. Nice to know that the MMA hasn't forgotten their roots. If anyone should be entitled to use Sequential's number, Dave Smith is the guy.

Monday, December 15, 2008

My order is in

Placed an order for a Synthesis Technology MOTM-650 MIDI/CV converter today, to take advantage of their end-of-year sale. The 650 is just what I need to bring flexible MIDI control to The Discombobulator. I like the idea of being able to drive a lot of different control voltages with the sequencer, and with the 650, you can get up to 12 control voltages out -- a pitch CV, velocity CV, and aux CV (assignable to a MIDI continuous controller) for each of four channels. After thinking some about where to mount it, I'm going to build a fourth block, which will contain the 650, a pair of envelope generators, and a VC panner, along with perhaps a mixer and whatever else I can fit in. This block will serve as the modular's primary interface with the rest of the world, taking MIDI from the sequencer and sending audio outputs to the mixer.

Procuring the 650 will allow me to dedicate the JKJ Electronics (RIP) CV-5 to the EML 101. For the past several years, the CV-5 has done double duty, interfacing to both the 101 and the modular. This has been a pain because the EML uses 1.2V/octave scaling, so every time I move it from one to the other, I have to re-scale it. There are, however, a lot of convenient features about the CV-5, which I'm going to have to work a bit to get the 650 to do the same things. One thing I appreciate about the CV-5 is that it contains a built-in MIDI-controlled panner; you plug in a mono audio signal, and it produces a stereo out. The panning is contolled by the MIDI Pan continuous controller, and it's internal to the interface. This is nice for automating panning during mixing; I do a lot of virtual-mix techniques, and to make that work you need the mixdown to be absoultely as automated as possible.

Other handy features of the CV-5: It processes pitch bend messages and adds or subtracts pitch bend from the pitch CV output, and you can set the bend range via MIDI. It also has a built-in LFO which can be added to several of the CV outputs, and the LFO can be sync'ed to MIDI clock. (It also has the ability to convert MIDI clock to DIN sync, but I don't use that.) A built-in portamento can also be programmed via MIDI and added to the pitch CV output, and there are several choices for note priority, velocity and aftertouch routing, and gate/trigger modes. (This includes S-trigger output, which is another thing I don't use since I'm not driving a Moog with it.)

Those are the sorts of things I've been looking for in a replacement for the CV-5, and the 650 fills the bill. Plus, it is of course built in the MOTM form factor, which the CV-5 is not. And, the 650 has lots of additional goodies, including built-in sequencing, microtuning tables (which work by offsetting the pitch CV output depending on what note is played), and the ability to update the firmware via MIDI. One little glitch is that there is an updater program for Windows and Mac OS9, but not OSX. I'm going to ask Paul S. if he's willing to document the updater protocol; if so, I'll write an OSX updater program and give it away to other 650 owners under GPL-type terms.

Saturday, December 6, 2008

Finishing Assembly of the MOTM-820

Picking up where we left off: Here's the remaining parts, waiting to be installed:

Most MOTM 2U-width modules have the right-side pots mounted on the PC board, and they are used to help support the board's attachment to the panel.  Here are the pots, waiting to be soldered:

One nice thing about the MOTM kits is that they provide pre-stripped and tinned coax for the audio I/O jacks:

And the rest of the I/O is done with twisted pairs.  At this point, all soldering on the board is done.

The panel, as it comes out of the bubble wrap:

Mounting the jacks:

The right way to tighten the jack nuts, without scratching the panel.  The piece of red tape on the socket helps me find it quickly in the toolbox, since I use this size often.

The mounted jacks.  I've left them a bit loose because sometimes it helps during soldering if you can rotate them, to make it easier to get the iron in.  I'll straighten and tighten them after soldering.

The PC board is supported by a metal bracket.  This shows how the bracket will mount onto the panel.  It fastens to two studs that are welded to the back of the panel.  The board mounts on the right side of the bracket, on standoffs.  The pot stems will go through the large holes and be clamped to the panel by mounting nuts front and back.  

Adjusting the mounting nuts on the pot stems on the back side of the panel, so that they are snug to the panel:

The completed mounting, with the board mounted to the bracket, and the bracket mounted to the panel:

This is what the panel looks like from the front at this point.  The two remaining holes are for a toggle switch and an LED that will both mount directly to the panel.

And now we pause for a cat photo.  This is DJ:

Soldering the coax and twisted pairs to the jacks.  I'm using the screwdriver to keep some tension on the coax while I solder it.  Note that at this point the switch and LED have been mounted and soldered, at the upper right of the panel.  

If you find that you have accidentally soldered something to the wrong jack, don't unsolder it; just swap the jacks around.  Of course, I never do that, ahem...

Last step: attaching the knobs.  

I admit it; I'm obsessive about knob registration.  

The completed module, ready to mount and test: