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Spirit Digital 328

8-buss Digital Mixing Console (Preview) By Paul White
Published June 1998

Spirit Digital 328

The Spirit name stands for quality analogue mixing at affordable prices — but can their new 328 carry the company's traditional values into the digital age? Paul White takes a first hands‑on look at Spirit's digital debut.

Digital mixers have been around for a few years now, but it's only recently that prices have fallen far enough to challenge analogue desks on cost grounds alone. A typical digital console includes a degree of automation, often with moving faders, and there's a tendency to include built‑in effects and dynamics processors — largely because it's cheaper to do that than provide additional analogue I/O to accommodate external boxes. This provides a lot of functionality for the price, but may well restrict the ease with which external processors can be connected.

With everyone competing on price, the main difference between models tends to lie in how the available processing power is deployed, and in the design quality of the user interface. This latter consideration is very important, as anybody brought up on an analogue desk is already used to having instant access to virtually any function, whereas with a digital desk it is invariably necessary to use multi‑function controls to keep the control surface manageable and affordable. The challenge is to make the digital control surface operate as much like an analogue console as possible, but without providing knobs and switches for every parameter.

Spirit have come into the digital mixer market after observing the strengths and weaknesses of the first generation of products, and though the overall functionality of their 328 isn't hugely different to that of similarly priced competitors, they have taken a different approach to the user interface. The main difference is the use of what Spirit call the E‑strip — a row of knobs above the channel faders that can be used either to access a single channel control (such as an aux send or tape return) across the whole console, or which can function as a virtual channel strip that provides one‑knob‑per‑function access to all the EQ, aux and pan controls of the currently selected channel.

Although we've already reported on this mixer, we didn't want to do a preview before the majority of the functions were implemented. At the time of writing, there was still a little tidying up to do in some areas of the software, and there was still some work to be done on the dynamics processors, but the console was otherwise fully usable. The processing power of the desk, for those interested in such things, comes from a Motorola 56002 processor.

Analogue‑To‑Digital Conversion

Spirit Digital 328

Spirit have designed the 328 to look as much like one of their analogue consoles as possible and, in analogue terms, it functions approximately as a 16:8:16:2 in‑line mixer with additional general‑purpose stereo inputs and direct channel outputs via the digital interface. In fact it's rather more than this, because all the tape returns, stereo ins and FX returns have the same routing facilities as the main input channels. Digital interfaces for Tascam (T‑DIF) and ADAT recorders are built in as standard: two pairs each of T‑DIF and ADAT, both in and out. You can get up to 24 tracks of digital recording by using both the groups and the direct channel outs, though you still only have 16 true tape return channels. Of course it would be possible accommodate 24‑track recording by bringing one of the 8‑track recorders back via eight of the analogue channels, which would also provide an opportunity to insert analogue processors between the tape machine and the desk. I use the term 'tape machine' throughout this preview, though the 328 is compatible with any digital recording system that has an ADAT or T‑DIF interface. Apparently Spirit have already used the desk with a Korg 12/12 PCI card‑equipped computer‑based hard disk recording system with no problems.

...within 10 minutes, and with no manual in sight, I managed to find my way around most of its features...

The 328 has two built‑in effects units based on Lexicon algorithms, two assignable dynamics processors (mono or stereo), and automation of all mix parameters with the exception of the analogue input gain controls. Apparently the Spirit designers felt it was better to include two really good dynamic processors than 16 perfunctory ones; the algorithms for these are designed by Orban and dbx.

When the desk is used on its own, it can provide snapshot automation (manually sequenced or MIDI controlled), with up to 100 snapshots of all the desk's digital controls, while full dynamic automation is possible with a MIDI sequencer. The automation can be referenced to SMPTE or MTC, and mixer maps are currently under construction for Cubase VST and Logic Audio to make operating the automation as transparent as possible. In dynamic mode the familiar read write and update modes of automation are supported.

The Channel Strip

The best way to understand the main features of this desk is to first examine a channel strip. (All 16 are identical, by the way.) The analogue input stage has an XLR mic input and a balanced jack line input controlled by a single Trim knob — phantom power can be applied globally. A switchable low‑cut 100Hz filter is fitted to each channel and there's a conventionally wired TRS jack analogue insert point following the input stage, after which the signal is digitised.

All 16 channel strips include a 10‑segment bargraph meter, switchable to show the mic/line channel levels, the tape return levels, or the master group and aux send levels. A record button is placed directly beneath the meter to arm a multitrack recorder via MMC. At this point, the E‑strip runs across all 16 channels. It comprises 16 encoder‑style knobs, each of which is surrounded by a ring of indicator LEDs, plus a row of switches for selecting Fader Bank (mic/line, tape or master), Meter Bank (mic/line, tape or master), and Rotary Control function select buttons that allow the knobs to access any of the aux sends or the pans across all 16 channels. An indicator LED shows whether you're working with the mic/line or tape channels (as both have identical features), and this status is flipped when the Fader Bank selection is changed. This kind of 'one control across the board' method of control is quite common in other digital mixers, but what sets the 328 apart from the rest is that when you select an individual channel, the 16 control knobs then work as a conventional channel strip with one knob per function. All the E‑strip's functions are printed beneath the knobs: frequency, gain and shape for three bands of parametric EQ (the outer bands can be switched to shelving), plus four pre/post selectable aux sends, and two further sends for the two internal effects and pan. The rings of LEDs around each knob indicate the filter bandwidth, gain settings and so on.

Below the E‑Strip, channel controls continue with channel Select buttons for both the Mic/Line and Tape banks, a channel Mute button and a Solo button, which works in either PFL (pre‑fade listen) or SIP (solo‑in‑place) mode depending on how you set it up in the master section. All the faders are full 100mm Panasonic motorised units, unlike the short throw types used by many of the 328's rivals. A single stereo fader controls the main output.

Master Section

Console master sections can be scary places, but the 328's is almost cuddly! At the top you'll find controls for all the analogue ins and outs for 2‑track tape, control room, aux sends and so on. As well as a choice of two selectable 2‑track returns, there are two sets of stereo analogue line ins with the same channel features and routing destinations as the main channels. The first of these, STE 1, has four stereo inputs that are mixed into one stereo pair with a level control for each, while STE 2 has a single pair of inputs. Of course, all four STE 1 inputs must be processed or EQ'd in the same way, but four mixable stereo inputs are a great way of bringing keyboards or effects returns back into the mixer.

The 2‑line backlit liquid crystal display looks more suited to a synth than to a digital mixer, but the truth is that you seldom need to look at it except when calling up a setting from a library or choosing an effect. Four cursor buttons steer you around the display, while another rotary encoder allows parameter values to be changed. A Confirm/Yes button acts as an enter key, and most actions can be undone or redone using the Undo or Redo buttons. It's in this section that snapshots and dynamics processors can be accessed.

Moving down the panel, there's a large SMPTE readout, plus transport and locator buttons that can be used to control any recorder that supports MMC (MIDI Machine Control). The physical rather than virtual button theme continues in the Select section where there are eight discrete Group routing buttons, as well as further buttons for channel Phase reverse, EQ In/Out, channel Direct outputs, SIP Safe mode, Route to Mix, Record Arm, Mute and Solo.

Routing is quickly and easily accomplished using a combination of the channel select buttons and the Route to Group buttons, and as all the console buttons are illuminated, the routing status can be clearly seen. Furthermore, holding down just a Group button in the master section causes the select switches in any channels routed to that group to light up, so it's very easy to check the channel routing. There are also discrete buttons for setting up the Solo status and for storing, recalling and stepping through snapshots.

Finally, internal effects levels can also be set via rotary encoders, and you can EQ and route effects in the same way as other channel signals (except that it's not possible to route an effect to itself, a sensible safety precaution to prevent feedback). Both the effects and dynamics processors are editable.

Operationally Speaking

What I liked most about this desk was that, within 10 minutes, and with no manual in sight, I managed to find my way around most of its features and was able to set up a mix quite efficiently. This is partly because the E‑strip makes setting the EQ, aux sends and pan far easier than on desks that offer access to just one control type at a time. Channel data can be copied to an adjacent channel simply by holding down the Select button of the source channel, then prodding the Select button of the destination channel, a simplicity of operation that is carried through most of the desk's switchable functions. As the mixer maps weren't complete, I was unable to check out the dynamic automation, which uses non‑registered controller data, but the snapshot system proved to be very straightforward. In addition to the 100 main snapshots, there are 20 further user setups that can, in effect, be hidden to prevent accidental overwriting. These may be used to store a starting configuration for a mix, including the I/O routing, sample rate, SMPTE frame rate and so on.

Though the analogue inputs have insert points, there's no straightforward way to insert an analogue effect into the signal path if you're using the digital tape returns. However, if the two on‑board dynamics processors aren't enough, you could use a spare pre‑fade send to route a signal to, say, a compressor, leave the channel fader down to remove the dry signal, then return the compressor output to a spare analogue input channel. It's also possible to configure the AES/EBU or S/PDIF connectors as master stereo insert points for use with outboard devices that have a digital interface.

With analogue in‑line consoles, it's common to have to share facilities between the main and monitor channels, but with the 328, both the main ins and tape ins have exactly the same facilities, so all you need to do is select the tape fader bank instead of the mic/line fader bank when you come to mix.

Impressions

So far, I've concentrated on the user interface and said nothing about the sound of this mixer. Despite its budget price, the 328 uses 24‑bit, 128x oversampling converters, and offers the ability to use noise shaped dither when reducing the output signal for 16‑bit media such as DAT. The dynamic range is quoted as 109dB for the mic input, and the sampling frequency can be selected from 44.1kHz, 48kHz, or external sync (over a 30‑50kHz range). Certainly the mixer seemed very quiet, though there was a very low level of audible hiss when the effects were switched in, but as more work has to be done on this section, I'll wait until the final review model before commenting. It's worth mentioning that the mic amps are Spirit's UltraMic design, so they should be as quiet as those on a good all‑analogue desk. Unusually, for a digital desk, the EQ has an analogue sound to it, and each band has a set frequency range rather than having all sections cover the full frequency range. Apparently designer Graham Blyth has put a lot of work into the EQ, and he may well do further tweaks before desk goes on sale.

I don't like to draw too many firm conclusions at the preview stage, but my initial impressions of the 328 are very positive. Its weakest points are the lack of any insert points in the digital tape return path combined with limited dynamics processing, and its relatively basic effects when compared with the competition. I'm told, however, that the effects capabilities will be extended in version 2.0 of the software to include dual effects such as chorus/reverb, delay/reverb and so on. On the other hand the user interface is well ahead of anything else I've seen to date, the built‑in digital interface for 16 Tascam/ADAT tape return channels (24 tape sends) is excellent, and all 16 main channels have both mic and line inputs. The provision of five stereo analogue inputs makes it easy to connect external effects units or to route other stereo signals into the mix and, if you outgrow the mixer, you can cascade two together with nothing more complicated than a single cable.There's a lot more I'd like to say about this mixer, even at the preview stage, but space prevents me — so you'll have to wait for the in‑depth, full review in a month or two. Spirit are confident that the desk will be on sale by early summer.

Optional Extras

  • 8‑Channel I/O: this connects to the T‑DIF port to provide eight unbalanced analogue group or direct outputs and inputs.
  • AES/EBU Interface: four pairs of AES/EBU digital ins and outs on XLRs. Connection is via the T‑DIF sockets.
  • Mic Preamp Interface: provides eight mic inputs using the same low noise Ultramic preamps as in the 328. Each input has a gain control, high‑pass filter, insert point, phase button and pad switch; connection is via the T‑DIF sockets.