Opcode's Studio 64X is aimed at those people who need more than just a simple 1-port MIDI interface, and thus represents the entry level of the pro or semi-pro market. It's a 4-port, 64-channel interface, MIDI patchbay and SMPTE box, all housed in a compact, 1U rackmount case. Opcode have been making MIDI hardware since the beginnings of MIDI, so they know what users need -- which is why two of the ports on the Studio 64X have dual output sockets. These built-in 'Thru boxes' enable you to use extra equipment on the spare channels of a port without needing to buy a separate Thru box. The Studio 64X can also generate or receive SMPTE timecode via two dedicated quarter-inch jack sockets.
For a long time Opcode have been associated with Apple MacOS computers, although many of their programs are now also available for the Microsoft Windows/Intel PC platform. The Studio 64X can be used with either of these computer types, although there is one major difference: the advanced MIDI processing facilities which utilise the Studio Patches application (see my two-part feature on using the Opcode Studio 5LX multi-port interface, in SOS October/November 1996, for more details on this) can only be used with a MacOS computer running Opcode's Open Music System (OMS). The rest of the supplied software is more or less the same across the two platforms -- even to the extent of having a special MacOS 'Windows Help' lookalike application so that the MacOS computer can have the same help file as the Windows version. It is possible to connect the Studio 64X to a Mac and a PC simultaneously -- amd when I tried this it correctly auto-detected messages from the two computers, although I didn't try anything unreasonable like trying to run MIDI sequencers on both computers at the same time! All of the computer serial port cabling, plus a plug-top mains power supply is supplied as standard with the 64X.
For this review I tested the Studio 64X using my OMS 2.3.1, System 7.5.5 (updated) equipped Mac Centris 610, and a Windows 95/3.11 Pentium PC (the Studio 64X software is not currently Windows NT-compatible). Installation on the Mac was straightforward. On the PC there were the usual serial port/Interrupt hassles, where you have to assign a COM port and an IRQ to the serial interface. Thankfully, Opcode provided a DOS-based diagnostic program which significantly eased the setting-up process. It is worth noting that the default installation settings in both versions of Windows did not work, and needed changes before communication could be established with the MIDI interface.
The Studio 64X enables you to route any MIDI input port to any of the MIDI output ports (although usually you don't connect something back to itself). It provides comprehensive control over exactly which messages can be sent out of each port, so it's possible to specify that only particular types of messages can pass, to choose which MIDI channel can pass through, or even to change the MIDI channel to a different one. All of the settings in the four available user routing programs are stored in non-volatile (battery-backed) memory inside the Studio 64X. Editing the patching, filtering and other settings can only be done via software on a computer -- but the routing programs are still useable without the computer.
The Studio 64X front panel has a minimalist user interface. The input and output monitor LEDs allow you to visually check that your MIDI signals are arriving at the patchbay, and that they are being routed correctly. Dim LEDs usually indicate MIDI Clock messages, while bright flashes are ordinary MIDI messages, and long bright LED flashes mean SysEx or over-use of pitch bend, mod wheel or aftertouch/key pressure.
Pressing the Program button advances through the four user programs first, then through the four factory preset programs. In each case the relevant LED flashes to show that that the program is active. The first factory program is a 'panic' mode, which sends Note Off messages for each note on each channel to each port, and is used when you get a stuck note. The MIDI/Thru push button selects whether the computer is connected to the Studio 64X, or to the printer, modem or other serial device. It is not easy to figure out which mode the button is in without actually pressing it to find out whether it is in or not! A better indication would have been useful, and would not have increased the cost hugely -- for example, it's possible to get buttons which reveal a brightly coloured band when they are in the 'out' position.
There are two things which worry prospective purchasers of MIDI Interfaces: delays and SysEx incompatibilities. I tested the Studio 64X with my standard 'Thru' delay timing tests, and the delay from the input port to the output port was between 250 and 350 microseconds for MIDI Clock messages. This is about the same as a single byte of MIDI information, and about a third of the time it takes to transmit a single MIDI Note On message -- a fine performance. For Note On and Note Off messages, the delay was longer: between 550 and 700 microseconds regardless of the filtering and channelising settings in the Studio 64X control panel, which is still pretty good. When using the more advanced filtering, splitting and processing functions in Studio Patches, on a MacOS computer, the delay increased to about two milliseconds (2000 microseconds). This delay is obviously longer, but even so it shouldn't present any problems at all, being undetectable for most purposes. During these tests I did notice that the Studio 64X needed to be reset sometimes when I jumped between its on-board patch programs and the OMS Studio Patches, but a reset is easily carried out from the front panel.
For System Exclusive, the concern is about the ability of the interface to cope with big blocks of data -- if the computer or the interface can't move the data around fast enough, some of the data might be corrupted. For this my usual test is to use the SysEx delay feature of my Emu Morpheus, which allows control over the delay between packets of SysEx data. The delay is normally set as 300 milliseconds, so I reduce it to zero and see if there are any problems with SysEx dumps of the complete memory of the Morpheus (about 24 kilobytes of data). The Studio 64X had no problems coping with this.
The Studio 64X provides SMPTE striping and synchronisation facilities. The front-panel SMPTE Stripe/Sync LED flashes slowly when the Studio 64X is generating SMPTE, flashing rapidly when receiving SMPTE. It sends an audio tone signal from the Sync Out socket even when it is not striping the tape, and this helps you to set the correct level on the tape recorder.
A special set of internal connections is also provided for the timing-critical MTC (MIDI Time Code) messages which are produced from the SMPTE sync signals. There's lots of information on SMPTE, sync'ing and striping in the on-line help.
The Studio 64X Getting Started guide is thin -- just 12 A5 pages -- but this is more than made up for by the excellent on-line help information. Since you need to use a computer to edit the patch programs, having help available on the computer as well makes a lot of sense. The help program will be familiar to anyone who has seen a Windows Help file or used the World Wide Web -- the green underlined text links you to more information, and the button bar at the top provides useful functions like Contents, Index, Go Back, Print, Previous and Next. Clicking around the help pages is significantly faster than thumbing through a thick manual. The help pages are well designed, with plenty of pop-up 'glossary'-style boxes to explain words, and lots of links to pages offering additional explanation. In fact, I would rate them well above many of the help pages for business software from names like Microsoft.
If you have a master keyboard (or even a synthesizer that you use as your main keyboard), drum machine and one or two expander modules, the Studio 64X is designed for you. It neatly fills the gap between the 1- and 2-port basic interfaces and the pro 8-port interface/patchbay/SMPTE sync boxes.
When you buy your second piece of MIDI equipment, and connect it to your first, you probably aren't thinking about the future. But when you buy a third, and decide to press your computer into action as a MIDI sequencer and digital audio workstation, then you need a multi-port MIDI patchbay and computer interface -- it's the 'enabler' for running a computer-sequenced MIDI studio. A MIDI patchbay is very similar to an audio patchbay: it allows you to make connections without needing to move plugs and cables.
If you have just one or two items of MIDI equipment, one of the simple (around £50) 1-port MIDI interfaces will suffice. Above this, the cost increases with the number of ports, up to the 15- or 16-port 'professional' interfaces which can cost around £1000. Beyond these, there are custom MIDI patchbays and interfaces made by specialist companies. You need to match your equipment to the number of ports: ideally, in these multitimbral days, you need one port per piece of equipment, with perhaps a spare port or two if you are considering buying some more MIDI equipment. Because an individual MIDI port is capable of supporting 16 channels of information, the Studio 64X's four separate MIDI ports support up to 64 individual channels of MIDI. This enables you to devote a port to each piece of equipment -- although, unless you intend to use the full 16-part multitimbrality that this provides, it also gives you scope for adding in extra equipment on spare channels.
There are two ways in which a MIDI interface and patchbay are used. The basic connections are the same in both cases: typically, the MIDI Out sockets of your MIDI equipment are connected to the inputs of the patchbay, while the MIDI In sockets of the equipment are connected to the outputs of the patchbay.
When the interface is being used between a computer and MIDI equipment, the inputs might be used to record MIDI information into a sequencer, and the outputs would then be used to play back the MIDI information recorded on the tracks in the sequencer. This is when the SMPTE sync facility is useful, since it allows the sequencer to be synchronised to a tape or video recorder. Alternatively, SysEx information from one piece of MIDI equipment might be recorded by a librarian program for editing or storage, or perhaps replayed from the librarian to restore a set of sounds. In this case, the interface is making a direct connection between the computer and the piece of MIDI equipment, which is why separate connections are needed from each MIDI In and Out socket.
But when used without the computer, a MIDI interface and patchbay becomes a way of connecting the equipment in a MIDI studio together. The patchbay can be used to route any of the inputs to any of the outputs, which means that any keyboard connected to the patchbay can be used as a 'master' keyboard to control any other sound-generating modules. In addition, one keyboard can be used to control several others, so that a stacked sound can be produced. It also allows a workstation sequencer and a drum machine to be connected, with either the workstation or the drum machine providing the MIDI clock messages, and no need to move any cables.
SMPTE synchronisation is a way of locking a computer sequencer to a timecode which is recorded onto a tape, thus allowing synchronised audio, video and MIDI work. All MIDI interfaces except the very simplest single-port versions tend to include synchronisation facilities. Basically there are two required functions: striping, which involves recording a timecode signal onto one track of a multitrack tape; and sync'ing, which involves receiving the timecode signal off the tape and turning it into timing information which can then drive a sequencer program on the computer.
The Studio 64X's case is quite small, so it comes as no surprise that the PCB fills much of the space inside. Unlike most of the very hi-tech synthesizers and expanders, Opcode have chosen to use conventional low packing-density, through-hole technology, rather than the higher packing density offered by surface-mount techniques.
The processor is an 80C32 micro-controller running at 12MHz. The serial lines to and from the computer are interfaced with the industry-standard 26LS31/32s and Max 232 chips. There are four custom dual-in-line (DIL) chips marked OPCODE, which may well be used for the routing and filtering operations. Memory is a Sharp 5116 RAM and an EPROM for the Operating System -- marked 'V01 1996'. Most of the chips are HC/HCT series 74 logic, all in DIL packages. The MIDI/Thru switch is a 30-pin monster which can be used to switch the Mac and PC serial lines onto the rear-panel Thru sockets when the Studio 64X is not being used.
Other Opcode Mac MIDI Interfaces include:
MIDI TRANSLATOR II:
1 port, 1 In, 3 Out £58.
MIDI TRANSLATOR PRO:
2 ports, 2 In, 6 Out £105.
2 ports, 2 In, 6 Out, SMPTE £269.
8 ports, 8 In, 10 Out, SMPTE £410.
15 ports, 15 In, 15 Out, SMPTE £939.
The Studio 64X sits between the Studio 3 and Studio 4 in terms of features and price.
Two ports have dual output sockets.
Stand-alone mode for basic patches.
MacOS or IBM PC compatible.
No front-panel indication of current program.
Needs computer for editing patch programs.
Advanced MIDI processing is only via MacOS computers.
A neat, entry-level pro/semi-pro MIDI interface, patchbay
and SMPTE sync box, well suited to a small MIDI system
in a home or project studio.
£ £269 inc VAT.
A MCMXCIX, 9 Hatton Street, London NW8 8PL, UK.
T 0171 258 3454.
F 0171 723 8150.