In part two of Nigel Lord's appraisal of the Yamaha Promix 01, he examines the effects processing capabilities of this groundbreaking mixer...

I wonder whether I'm alone in finding onboard effects processors – the kind which pad out otherwise pretty average synth modules – often more interesting and characteristic than dedicated effects units. Could it be that their lower fidelity and realism only serve to increase their sonic interest? Of course, it's also just possible that certain combinations of synth presets and FX programs add up to more than the sum of their parts.

Whatever the reason, I'm happy to report that ProMix's onboard effects processors offer an impressive compromise of character and sonic realism. So much so, that provided you don't have a penchant for some special program only possible on your current effects processor, you could seriously think about selling it off and simply using ProMix's onboard FX. Obviously, with two auxiliary sends in addition to those for the internal FX, it would be useful to keep all your processors and have them all accessible simultaneously.

For those struggling to afford ProMix in the first place, it might be an option worth considering. For the ProMix offers a range of FX programs, which both in terms of versatility and quality are the equal of most of the dedicated processors currently in use in domestic and semi-professional environments.

Not that this is particularly surprising; Yamaha have been known to put together one or two useful designs over the past few years. Indeed, it could be said they have something of an effects-processing pedigree to drawn on – and live up to.

That said, there's nothing here that's going to drag you in by the lapels and have you gasping in disbelief; the ProMix effects are well thought out rather than inspirational, but none the worse for that. Like the EQ and dynamics processing, it is their sheer convenience which is their greatest asset. Patching in is dead easy, using broadly similar screen pages to other processing functions and drawing on some thirty preset programs and ten user programs.

Given the absence of any insert points on the main stereo mix, I would have liked to see an exciter program included as part of the effects set. I'm not a great believer in aural enhancement effects, but they have their uses in livening up the occasional dull mix. With the ProMix, you're given neither the facility to patch in your own unit, nor the necessary built-in effects for routing to the main outputs.

I was also about to criticise the limited number of user programs, but then I read the manual properly and realised that the current effects program is saved (along with the EQ and dynamics parameters) as part of a Mix Scene – and you can store an impressive 50 of them.

With its exceptionally well-written manual and tutorial, getting to grips with ProMix is both quick and painless. For what is a genuinely revolutionary machine, it is perhaps surprising that no conceptual leap is required on behalf of the user. Despite its all-digital format, it still feels very much like a conventional mixer. And as I said earlier, for anyone used to handling existing digital gear such as synths, sound modules and samplers, there should be no barrier to quickly getting the best out of ProMix.

I would have been prepared to bet hard cash that the one thing that wouldn't be included on a MIDI-controlled digital desk retailing for under £2,000, would be motorised faders. Yet here they are, moving up and down in a way that leaves you feeling slightly uneasy – rather like watching the keys of an old pianola with no-one sitting there.

It's important to realise that these are not simply channel faders, but dual-parameter controls which, if Send 1, 2, 3 or 4 functions are selected on the LCD screen, also act as channel-to-send controls. In addition to the sixteen main input faders, there are also faders for the stereo input Chanels, for the selected Return/Send channel and for the main stereo output pair.

Additional top panel hardware includes rotary channel gain controls and -20dB attenuator pad buttons, individual channel select and channel on buttons, plus rotary monitor level and phones level controls. Presumably, the latter have been left in hardware form so that you can quickly kill output level to save your ears/monitors.

Centre stage, you'll see the main programming section, with that impressive 240 x 64 dot backlit LCD and easy-access contrast control, and a key-pad style button matrix to control all the major functions. The contrast control could prove invaluable on stage, with the angle of light constantly shifting. Data entry is via the large and easy-to-use Parameter wheel and Enter button, with cursor movement provided by four directional switches.

Round the back, inputs channels 1-8 are on balanced XLR connections; channels 9-16, though also balanced, are on stereo jacks; and the additional stereo input is via twin unbalanced mono jacks. Phantom power is provided on the ProMix (and there's a switch here to prove it) and of course, there's the obligatory MIDI In and Out ports. Additional connections are provided for the main stereo output pair on balanced XLRs, for monitor outs on a pair of unbalanced mono jacks, and for record out on both unbalanced mono jacks and digital coaxial (phono) sockets. There's also a single stereo jack for headphones.

Effects signals associated with auxiliaries 3 and 4 are sent by a single pair of mono send jacks and returned via, well... nothing actually. Returns from your external effects apparently have to be routed back through the stereo input. This wouldn't be so bad if effects returns weren't stereo, or there were actually two stereo inputs. As it is you'll either have to use only effects which work in mono, or limit yourself to a single external processor. The other options would be a unity gain 2 into 1 mixer of some description; luckily I have a Mackie signal combiner which will do the trick, but with nine combined inputs, a pair of combined stereo outs, plus combined phones out, it's like using a sledgehammer to crack a nut.

Yamaha also provide a 2-track return on the ProMix, which if no plugs are inserted into the Stereo In sockets, actually uses the EQ facilities associated with this channel. As is the way with most mixing desks, the 2-track channels are isolated from the rest of the mixer in so far as they are monitored separately. This prevents feedback occurring when recording and monitoring on the same machine.

Speaking of monitoring, the facilities included on ProMix remain as they were when Bob Dormon had his encounter with the pre-release machine back in July last year. But just to recap...

Monitoring is carried out in what Yamaha refer to as Cue mode, which has its own page within the LCD screen. From here you have an overall view of what's going on in each channel (replete with a miniature version of the EQ display). The Cue signal is sent to the Monitor and Phones output and provides three options. The first, Mix, is related to the Cue screen in so far as channels selected here are added to the Cue mix – stereo channels always being selected in pairs. In Last Cue, only the currently selected channel is cued, 'though again, stereo channels are selected in pairs. Finally, in ST Fix, Cue monitors the main stereo outs and is unaffected by functions selected in the LCD.

That just about covers all the main ProMix features, but with a machine of this sophistication, there are bound to be a number of interesting little touches that serve to make life that much easier. For example, faders can be grouped together for multiple control from a single fader, making it easy to control several channels simultaneously. This applies to all input channels and stereo input channels, and you can run a maximum of four groups at any one time. Perfect for fading out a fully-miked drum kit using a single control. An additional function makes it possible to pair all adjacent input channels to accomodate stereo inputs; again, single fader control is all that is needed.

Although I haven't mentioned much about scene memories – other than that you have fifty at your disposal – it's worth just mentioning that they may be given names up to 8 characters long, they can be recalled using MIDI program changes, and they can also be saved and reloaded via a MIDI Bulk Dump/Request.

Finally, I might just draw your attention to the internal oscillator which produces a highly accurate sine wave or pink noise signal for calibration: an initialisation facility for returning all parameters back to their factory defaults; and a check page within the LCD for the battery on which your RAM is ultimately dependent. Enough...!

In a sense, Yamaha's monopoly on the digital MIDI-controlled mixer market obviates the need for a balanced summary. The ProMix is, simply, number one in a field of one. That said, it would have been easy for them to make economies in several areas, in the knowledge that this was the only machine offering MIDI-controllable mixing. I think the fact that the only absent features of the ProMix are a pair of digital inputs and a more flexible means of returning external effects signals, speaks most highly of Yamaha's marketing approach.

The only criteria on which the ProMix 01 can be judged, is of course, price. But again, Yamaha have the jump on us. With decent quality 16-channel analogue desks currently commanding around £1200+, a machine of this sophistication might have been expected to top the £2000 mark. That it is available for considerably less is better, I'm sure, than anyone dared hope for.

Wisely, Yamaha have been co-operating with the major MIDI software houses to produce ProMix interfaces for the leading sequencer platforms. Logic is already complete, Cubase is on its way, others will doubtless follow. The final assimilation of MIDI into the music production process appears to be complete.

With its release into an age where the importance of 'the mix' has at last come to be appreciated, one can only conclude... this machine changes everything.

For a multimedia experience of the ProMix 01, try out Yamaha's own interactive demo on the CD-ROM. Not only can you learn more of its capabilities, you can also hear what seasoned professionals think of it...

For those of you who use EMagic's Notator Logic on Atari or Mac, we've also provided ProMix 'environments' for controlling your mixing from your sequencer. A Cubase version should be available shortly...