Emagic AMT8

Colin Owen rediscovers the joys of Atari‑tight timing on his blue G3 Mac with Emagic's AMT8 interface, featuring their new Active MIDI Transmission.

The AMT8 is the first of a new generation of Emagic MIDI interfaces designed to work with the USB protocol, as well as both Mac and PC serial ports. This former facility will be of particular interest to owners of the newer Mac G3s and G4s, as these have no built‑in serial port, and USB is also available on some PCs, though I haven't had the opportunity of testing the device with a PC. There has been a lot of talk about the reliability of USB in regard to MIDI, particularly in terms of timing accuracy. As we'll see later, however, the AMT8 has this pretty much cracked.

The AMT8 is a relatively straightforward eight‑input, eight‑output MIDI interface, but it boasts Emagic's new Active MIDI Transmission technology. This, in conjunction with Emagic's Logic sequencer, uses a clever look‑ahead buffering system to improve the timing of MIDI signals at the interface ports. The interface also has a MIDI patching facility, controlled by editing software for Mac and PC that comes on an included CD‑ROM. Also included are all the various cables you may need for connection to a computer — USB, Mac serial, and RS232 for the PC — and, of course, the obligatory wall‑wart power supply and printed manual.

A straightforward installer takes care of the software setup, and the manual is quite clearly written with copious detail on all aspects of the unit's setup and operation for both Mac and Windows systems. It also has useful troubleshooting and glossary sections.

Seven of the AMT8's eight MIDI Ins and Outs are on the rear of the unit, with MIDI In and Out number eight located on the front panel so you have somewhere to plug that visiting synth. The bright blue front panel is clearly laid out, with its two MIDI ports to the left, eight red LEDs for MIDI input activity and eight green LEDs for MIDI output activity. Three orange LEDs indicate which host interface is being used and a panic (all notes off) button doubles as a mode switch. There's also a red LED to indicate whether you're in patch mode or computer mode, and a power button with a further red LED. All the LEDs are bright and clearly visible.

In addition to the seven MIDI ins and seven MIDI outs, the rear panel houses the RS232 PC, RS422 Mac serial, USB, and power sockets. In many respects, the AMT8 is a scaled‑down version of the forthcoming Unitor8 MkII. As such, it has none of the latter's sync features, and (unlike the Unitor) its firmware cannot be updated via MIDI. There's also no 'click' input or host‑through socket as on some other interfaces. Even so, most people will find they have all they need, as the AMT8 happily accepts MTC (MIDI Time Code).

AMT is Emagic's answer to MIDI timing problems, and though I don't know all the details, I gather it works by sending the data to the interface slightly early, after which it is clocked out exactly when needed. I can remember how in the days of the Atari, music used to 'feel' right as well as be in time. For me, that was lost when I moved to the Mac, with its serial interface: the Mac definitely lost something on the timing front. You can improve things by using interfaces on both the printer and modem ports, thus spreading the load around a little, but to me, music never felt the same as when I used the Atari — until now. I'm happy to say that the AMT has recaptured that musical feel, for me, and the absence of all those little delays is very noticeable — things really come to life without them. I'm converted, anyway. Note, however, that since Active MIDI Transmission depends on specially written software, the only sequencer it currently works with is Logic: when used via OMS, as you would with a different sequencer package, the AMT8 behaves just like a standard multi‑port interface.

Using The AMT8

In old‑fashioned Mac serial mode (hooked up to my G3 via a Stealth card) the unit worked perfectly first time. However, I encountered a snag working in USB mode: for some reason, mapped instruments in Logic are not transmitted, and their MIDI Thru function doesn't work either. Sending the same mapped track data via a non‑mapped instrument works fine, so I suspect the problem lies within the Logic software rather than in the interface hardware. To confuse things further, If you open a second output to the modem port (Stealth port in my case) with a second serial MIDI interface connected, it turns out the missing mapped data is being sent to the modem port, even though the track is ostensibly routed to the USB port of the same number. Emagic claimed that they would try and fix these problems in the next software upgrade, but a new version appeared just as I was finishing this review off and the problem remained.

OMS does not escape unscathed, either. If you're an OMS user you'll have trouble with mapped instruments too, only this time the data will be sent to all USB ports regardless of where you try to route it. Mapped instruments seem unable to access the OMS studio setup items directly, though sending the data via a non mapped track is an instant workaround. The OMS driver that came on the CD could not recognise USB at all, so OMS wanted to see the AMT8 via the modem port. Clearly this is no good if you're using a recent G3 or new G4 and you haven't bought a serial‑port card! The good news is that Emagic's web site offers a beta version of a driver that will fix this problem. I downloaded and installed the newer driver and it did indeed fix the problem, even though OMS wasn't entirely happy about it, and kept complaining that it still couldn't see the AMT8 via USB. Clicking on the 'Forget about it' button seemed to solve the problem, and OMS happily communicated with the AMT8 that it claimed it couldn't see! Such joy.

For those of you who already have a synchroniser that can output MTC, it is possible to achieve sync via the AMT8: simply plug the MTC source into one of the AMT8's MIDI inputs and you're in business. I got the AMT8 to sync up perfectly with the timecode on my ADAT using this method (I used my other interface as a stand‑alone SMPTE to MTC converter).

AMT8s can be used alongside other interfaces to increase your I/O options, should you so desire. If you're a blue‑and‑white G3 owner you can buy an AMT8 with confidence that it will work, and you can still use your old serial interface — mixing USB and serial is no problem. You can even have two computers plugged in at the same time.

Conclusion

There two reasons to buy this unit — AMT, and USB. AMT is definitely worth having as the improved timing is wonderful, though no other software companies have yet taken advantage of it as far as I'm aware (though Steinberg are planning to support AMT). If you don't need sophisticated sync options but do need a multi‑port USB MIDI interface, the AMT8 is a good solution, and you can still achieve sync with MTC via any MIDI input. The mapped instrument problem needs to be resolved sooner rather than later, and I'd like to see the system coexist rather more solidly with OMS, but for routine work, it's exactly what's needed.