Martin Russ shows his age and his roots as he looks at a thoroughly modern recreation of a bygone age — Emu's Proteus-based Vintage Keys module.

Here's your shopping list: Farfisa Organ; Solina String Machine; Yamaha CP70 Piano; Moog Modular System 55; Sequential Prophet 5; MiniMoog; Fender-Rhodes Mark 1 Piano; Rhodes Chroma; Hammond B3 Organ; Oberheim OB-Xa; Wurlitzer Electric Piano; ARP 2600; Hohner Clavinet; Moog Taurus Bass Pedals; Mellotron; Fairlight CMI; Yamaha DX7.

At today's equivalent prices, you might get some change from fifty thousand pounds — if you could still buy them. These are the instruments that shaped the sounds of popular music from the '70s through to the mid-80s. Many of the current Sample & Synthesis (S&S) instruments attempt to provide vague emulations of some of these, but no-one had really approached it in any serious way outside of the larger sample libraries. Until now.

The Emu Vintage Keys is not just another version of the Proteus. This 1U high rack module is dedicated to producing classic sounds from the early days of synthesizers, when programming was king and memories were unheard of. The H-series chips give the Vintage Keys several notable features which have been missing so far in the Proteus range: resonant filters, envelope retriggering and portamento, for example. Analogue synth extras, with samples of the original instruments, at an affordable price?

SO WHAT'S NEW?

The Vintage Keys breaks away from the established Proteus series of instruments in several ways. The front panel has been redesigned to make it easier to use, and the sculptured plastic casing has been replaced by a more utilitarian enamelled and folded steel cover. I always wondered why all that effort had gone into the Proteus box when all you did was hide it away in a rack, and so I was pleased to see that the Vintage Keys actually puts the gloss where it is visible — the front panel is black anodised brushed aluminium alloy. With the addition of some glossy black plastic surrounds for the knobs and mains switch, the overall appearance is significantly enhanced — it looks expensive.

Placing the backlit green LCD behind a larger recessed window helps the looks and improves the viewing angle; I could never read the Pan setting on the Proteus without moving round to look at it straight on. Looks aren't everything, although with a module which is designed to emulate some instantly recognisable instruments of old, it is good news that Emu have put considerable effort into making the Vintage Keys stylish.

So, nice design, but what about the sounds? Emu's are known for their skill and attention to detail in making the most of available memory space, and the Vintage Keys contains some instantly recognisable source samples as well as lots of single cycle waveforms. The quality is helped by the 18-bit DACs, where the two extra bits (the data is stored in 16-bit linear format) should help keep noise low and dynamic range high — especially important where there is lots of mathematically demanding processing, as required by the Vintage Keys' (digital) filters.

Ultimately, however, it is the variety and depth of timbral resources which matter, and although this is good there are a few minor weak spots which brings me to the trump card in Emu's hand — the expansion ROM. The basic Vintage Keys comes with 8MB of ROM, and there is a special SIMM socket for expanding this to 16MB. If you've installed extra RAM in your computer you will know how easy SIMM sockets are to use — which makes quite a change from the awkward (and rarely user-installable) connections used by most manufacturers.

One obvious benefit of the extra ROM option is that Emu have the flexibility to correct any unforeseen omissions in the expansion ROM. The major missing element in the initial 8MB is the DX7 Electric Piano sound, that tinkly sound which was well over-used in the mid-80s. I would also have preferred some more 'electronic' drum sounds to suit the analogue theme, but then the unit is called the Vintage Keys, after all.

PROGRAMMING

Excellent samples taken from a wide variety of classic keyboard instruments are not necessarily a guaranteed recipe for good sounds. Analogue synthesizers need dynamic filtering, portamento and envelope retriggering if they are to sound authentic, and sampling filter sweeps eats memory and fixes just one 'snapshot'. The Vintage Keys uses a digital emulation of the classic resonant low-pass filter, providing the gentle roll-off of the 2-pole 'Oberheim' style filters, and the steeper, more synthetic sounding 4-pole 'Moog/Prophet/ARP' filters. An auxiliary envelope generator can be used to provide the independent filter sweeping that characterises late-70s and early-80s VCF-dominated synth sounds.

Unlike some competitors' digital filters, Emu let you modulate the filter cut-off with lots of different sources all at once. So, if you want to use an LFO for timbral tremolo, whilst sweeping with a decaying envelope, and still have after-touch brightness control, you can have it all. (You can also by-pass the filter entirely, which produces a louder, brighter sound than with the filters apparently wide open. Actually, because of the way that the filter modulation works, you can't open it fully by using just the frequency control — you need to use the Aux envelope or some other controller to really open it, and then the difference is much less marked.)

Apart from the filter and other analogue extras, the Vintage Keys has the same synthesis structure as the Proteus. There are two 'oscillators' producing the basic raw timbres — although Emu complicate things by calling them 'Instruments', and the samples are often multi-sampled or looped so you get a much more finished sound than you might expect. You can modulate the pitch and level of these with a wide variety of sources to produce panning, velocity crossfades and time crossfades.

The synthesis power of the Vintage Keys is deceptive. There is a lot of flexibility built in, although this is not immediately obvious from the editing pages. Some aspects are less than obvious, even given the clear and somewhat 'laid-back' style of the user manual. For example, the Alternative envelopes took me a while to figure out — for each basic sample/wave, there is a default envelope, whilst the Alternative envelope allows you to define your own custom envelope. Although this sounds simple, it means that you can happily change the envelope without anything happening to the sound unless you have the Auxiliary envelope turned On — conversely, it is very useful for making quick A/B comparisons whilst programming.

MODULATION AND EFFECTS

The MidiPatch Modulation System provides comprehensive routing of the keyboard and velocity controls, as well as the real-time controllers like the such LFOs, Auxiliary envelope and MIDI Controllers. You do need to carefully plan out what you want to achieve with the modulation routings because unlike with analogue synthesizers, where there are often level controls at the input and output of modules, Emu provide adequate but more frugal numbers of level controls for the Vintage Keys. Old instruments rarely had effects units built into them, and so the Vintage Keys does not follow on from the lead set by the Emu Proteus Master Performance System (see Jan/Feb '92 SOS). The Vintage Keys returns to the Proteus style in another respect: the 'Detune + Double' of the MPS is back to being called 'Chorus'.

"If you want to use an LFO for timbral trentolo, whilst sweeping with a decaying envelope, and still have aftertouch brightness control, you can have it all."

INSIDE

The Vintage Keys box is small (just under 9" deep behind the front panel), which might make you suspicious about exactly how much is inside. Actually, you get a lot for your money. The inside contains a small universal 110/240 mains power supply and the main PCB, with some smaller PCBs on the front panel. The main PCB uses almost exclusively surface mount technology — which means that it uses components which are typically about half or even a quarter the size of normal 'thru-hole' components and 'glues' them to the surface of the PCB with the solder connections. The board may be small, but there is a lot on it. Build quality was very high — the PCB and interior were neat and tidy. A thoroughly professional product.

The main processor inside is a Motorola 68000, and the three large ASICs (Application Specific Integrated Circuits: custom chips) were made by AMI. The six DACs (digital-to-analogue convertors) are Analog Devices AD1860s; the PCB is designed to take either the thru-hole or surface-mount versions. AD1860s are capable of running at up to 8x over-sampling rates, and this could explain the simple active filtering on the audio outputs — the combination of a high quality DAC and gentle filtering offers a good way to achieve excellent audio performance.

Perhaps the most interesting aspects of the interior are the two spare ASIC positions and the memory card provision. The original Proteus had those annoying slots that looked like card slots but weren't, whilst here the PCB is ready for a card connector, but the front panel isn't! I assume that the extra ASICs might be used to double the polyphony to 64 audio channels on a related product, and the card slot may be for a future product which uses the same PCB. Given the rapid pace of Emu releases (Proteus 3/World, Procussion, Proteus MPS and Emax IIIP in the last year or so) there may yet be more surprises, but at least you now know some of what to expect.

MIDI MATTERS

The Vintage Keys provides a Program Change Mapping Table to map the 384 patches to the 128 available MIDI program change messages. You can also access banks of patches using SysEx messages — but not by using a General MIDI type Bank Select Controller. MIDI Overflow can be used to pass notes beyond the basic 32 to another module — although why the manual calls note 'stealing', note 'ripoff' is beyond me... Multi mode allows the Vintage Keys to respond as a 16-part multitimbral synth, and the default display lets you access all 16 channels very easily — if only every expander module was this easy to use.

The SysEx implementation is comprehensive, with support for the MMA tuning standard, bulk dumps, and even conversions from Proteus patches. There are eight global velocity curves to match Master keyboards to the module. Perhaps the most novel MIDI extra is the use of note numbers to choose characters when naming the patches — you can 'play' the name instead of scrolling with the data entry knob.

A welcome addition to the specification sheet are the MIDI response times — 4ms for a single note is about the average for current instruments, whilst the 7ms for layered notes is somewhat better than the norm. As I mentioned in the March 93 issue of SOS, MIDI response times are an ongoing project of mine...

CONCLUSION

The presets didn't immediately grab me, although the front panel was much easier to use than the Proteus — what a difference a new layout, larger Data knob and an extra button makes — but when I started to do some editing and programming the Vintage Keys suddenly took on a different character. I was able to quickly reproduce my favourite Oberheim sounds, as well as some classic Prophet sync sounds, and my impression changed. With lots of scope for user programming, and extra MIDI Files of sounds from Emu, the supplied RAM presets are probably not fully representative of what you can do with the Vintage Keys. A disk of the sounds I programmed during the review period will soon be available from SOS, and Emu's Dave Bristow is also working on sounds.

My opinion of Vintage Keys changed from 'not sure' to 'rather impressed' just because I took the time to explore it — this is a timely reminder that you can't review something from the specs alone, or from only a brief audition in a shop. The Vintage Keys is a very powerful and capable addition to the Proteus range — the filtering and portamento that you couldn't do before is now available in a unit which complements the existing products very, very nicely. Rock/pop (Proteus 1), classical (Proteus 2), world (Proteus 3), percussion (Procussion), and now analogue (Vintage Keys) — what next from Emu?

Further information

Emu Vintage Keys £869 inc VAT.

Emu UK, (Contact Details).