Issue 59
Read Next:



February 2, 2007



Bristling with ‘scads’ of I/O, the latest Digimax contender looks to inexpensively bolster just about any DAW-based rig.

Text: Brad Watts

The more Presonus equipment I see, the more impressed I am. The Central Station monitoring system, for instance, had me salivating when it was first released. After having already purchased a similar monitoring device just a few weeks earlier, I remember feeling slightly miffed that the Central Station had appeared on the market when it did.

This week I’m on the lookout for an inexpensive eight-channel preamp, so it was an unexpected bonus when I received the Presonus Digimax FS for review. Presonus has a good deal of experience designing this style of converter/preamp combo by now, which it’s gained through the production of its previous Digimax and Digimax LT devices. The Digimax FS serves up the widest array of features of the lineage but still manages to come in as the least expensive of the entire Digimax range, perhaps due to its Chinese manufacture. The FS also foregoes the usual Presonus brushed aluminium fascia and instead uses plastics on its front panel. The remainder of the unit is plate steel and extruded alloy.

Like its brethren, the FS is a single rackmount unit of 150mm in depth. Unlike previous incarnations, however, the Digimax FS has its Neutrik combo XLR/TRS input connectors arranged across the front panel instead of the rear. I imagine Presonus’ R&D reckoned this offered better access to the input connectors for the majority of its projected user-base, such as people wishing to add a further eight inputs to their Digidesign 001/2, RME, MOTU interface etc. Besides which, Presonus has packed a smorgasbord of I/O into the rear panel leaving no room to mount real-estate-hungry XLR connections anyway.


So what’s going on out the back, I hear you ponder? Scads of I/O, basically. Eight balanced TRS jacks provide direct analogue outputs from each of the preamps – useful if you’re using the unit in a stand-alone situation to send the mic preamp outputs to a separate recorder. There are eight balanced TRS outputs from the Adat or SMUX-connected outputs, with the final eight TRS jacks configured as insert points for the eight preamps. All up, it’s an incredibly comprehensive complement of I/O and, as previously mentioned, a much larger feature set than any previous Digimax design. Aside from the analogue connections there are Adat and SMUX optical inputs and outputs, so a full complement of eight ins and outs is possible all the way through to 96k (the FS will support 44.1, 48, 88.2 and 96k sample rates). Wordclock in and out is present with a termination button should the FS find itself at the end of the clocking chain – nice one. Power is supplied via an external powerpack.

Of the XLR combo inputs on the front panel, the first two are also capable of receiving high-impedance instrument signals. The remaining six TRS inputs are happy with line level signals. To the left of these are two phantom power buttons. Yes that’s right, only two. Phantom power is switchable for Channels 1-4 and 5-8. This is an occasion where the FS falls short of the older Digimax designs, both of which supported individual phantom power switching. Personally, this limitation irks me, although it may be of no concern to others. If panel space is a premium I’d rather manufacturers used smaller recessed switches accessible via a ball-point pen, than lump the phantom power into groups. Sure, many studios can just leave their phantom power running all the time, but personally I’d prefer to engage it on a mic-by-mic basis, without the added concern of what mics are receiving power that shouldn’t. Regardless, the Digimax’s phantom supply provides the full 48V and ramps up and down slowly when switched on and off to avoid clicks and thumps.

Off to the right of the XLR inputs are eight stepped gain controls allowing up to 60dB of mic amplification (according to the panel printing), although the manual specifies the maximum gain at 55dB. Each gain knob has a single clip indicator LED and no pad or polarity switching either – again, no doubt due to the lack of space, but both these requirements can be effected with a quick bit of DIY and building some in-line pads and phase reverse cables [which you should mark clearly to avoid them causing you grief at some later date – Ed.]. Aside from the gain controls, the only remaining switches select internal sampling rates and word or Adat external sync. All the pushbuttons glow a contemporary blue with the Adat/BNC sync button alternating between red and blue, depending on the flavour of sync required.


Like most of Presonus’ equipment, the Digimax FS is none too shabby in the specs department. Frequency response is 20Hz through to 40kHz, with an A/D dynamic range of 107dB and a D/A dynamic range of 110dB (both of these figures are A-weighted).

The mic pre’s themselves (according to Presonus) use 30V rails and a Class A, discrete design, so there are no integrated chips (ICs) employed in the circuit. Sonically, the preamps sound quite presentable; they offered plenty of bottom and a smooth top-end to most of the signals I ran through it. I didn’t find the sound at all grainy or forced; they’re honest, useful workaday preamps. As I mentioned, I was keen to hear the Digimax FS for personal reasons as I’ve been looking for a reasonable set of Adat lightpipe-equipped I/O to expand my current system and eight useable mic pre’s. I’m of the opinion that these preamps will suit my situation – better-than-average, clean, while adding eight line I/O points to my rig. I can use it with either of my two systems as they both utilise the Adat format (but they don’t have SMUX, unfortunately). In any event I can see myself holding on to this unit regardless of what system I’m using. With the FS’s SMUX I/O it should remain ‘future-proof’ – at least for a couple of years. In fact, an inexpensive 16 I/O 96k rig could be made by simply combining two Digimax FS units with M-Audio’s ProFire Lightbridge. Now that’s got me thinking…



Leave a Reply

Your email address will not be published. Required fields are marked *

More for you



Issue 59