DBX 580: 500 SERIES MICROPHONE PREAMP — AudioTechnology
dbx managed to pack loads of control onto a 500 series front panel without it getting overwhelming. What’s more, the 580 preamp’s sound is as clean as it looks.
Review: Greg Walker
I’ve always been a fan of the dbx sound. Whether it be patching a kick or bass guitar through a vintage 160VU compressor, tweaking a 160A in a live rig, or running a vocal through a 902 de-esser in an old 900 series rack. There have been few more reliable or sonically useful brands throughout the last 30 years in both live and studio environments. Owning a 900 series rack of compressors and EQs myself, I was doubly curious to check out the new and very affordable 500 series modules recently released by dbx. In the next issue of AT we’ll be looking at the new compressor, de-esser, EQ modules — which build on the heritage of the older designs as well as an innovative subharmonic synthesiser. For this issue, we’ll be focussing on dbx’s new foray into the world of preamplification — the 580 microphone preamp.
LAID OUT RIGHT
I’ve got to say right off the bat that I love the look and feel of the 580 preamp. I don’t know if it’s dbx’s long experience with designing compact circuits for the 900 series cards but I’ve seldom seen a better laid-out set of controls on a 500 series unit (and I’ve used and reviewed a lot of ’em). There’s plenty going on in terms of controls with continuously variable gain, high and low ‘detail’ boost and low cut filter knobs as well as no less than six switches for phantom power, 20dB pad, polarity invert, low cut enable, detail enable and mic/instrument selection. Add to that a lovely backlit VU meter for output gain, a variety of coloured LEDs that indicate which of the controls are engaged, plus a peak meter and a jack input for Hi-Z instruments, and you’ve got a very well populated front panel that nevertheless is clear and easy to ‘read’. In use the dbx 580 feels very pro with all controls being smooth to the touch and the switches robust in operation. The busy front panel is surprisingly quick to acclimatise to. The only control that is slightly difficult to get at is the phantom power switch and this is fine by me as its location makes it very difficult to accidentally engage — a smart and subtle bit of design nous by dbx.
DEVIL IN THE DETAIL
Perhaps the most notable feature of the 580 preamp is the inclusion of high and low ‘detail’ controls which are basically EQs under another name. The high detail control introduces a shelving filter with a corner frequency of 10kHz, useful for adding top end clarity and focus on things like vocals and acoustic instruments. Low detail is a more complex circuit that simultaneously introduces a bell filter boost centred around 125Hz and another bell filter cut around 400Hz. The combination of these two EQs plus the low cut filter (a 12dB/oct Bessel filter that is continuously variable from 30-300Hz) means there is a tremendous amount of tonal sculpting available prior to hitting tape or DAW.
The preamp circuit itself is a fast solid-state design offering up to 60dB of clean gain, probably not enough for old school passive ribbons and dynamics on quieter sources, but more than adequate for most other applications. There’s no ‘warmth’ or ‘drive’ controls to be seen so if you’re looking for saturation effects best to look elsewhere. I know I’m not alone in often liking to use gear that has an inherent colour and/or drive to it for imbuing sources with character, but having said that, there are many situations where what is required is a clean, transparent signal path with quick transient response that allows things like drums and percussion to pass through unscathed. Such preamp circuits retain their clarity and punch under duress, and this is where I see the dbx 580 doing its best work.
My first experiences with the dbx 580 were with an active ribbon mic on percussion instruments where I was immediately pleased by the nice full frequency response and smooth definition of the sounds. When I switched to violin I was similarly impressed and I found the full-bodied tones from a number of overdubs combined well and sat sweetly in the mix. Next up were acoustic guitar and drum room duties using a Soyuz 017 tube LDC. Again the results were good with a nice sense of body to the sounds. When I engaged the high detail control and added 3-5dB of boost the acoustic gained a sweet sheen up top without getting too clangy in the upper mids, and I also found the high detail boost to be a real winner for drum tracking with a similar sense of refined clarity on overheads and room mic without too much harsh cymbal wash or nasty transient behaviour. Conversely, the low detail boost came in very handy on a couple of bass guitar tracks where the extra emphasis on the fundamentals gave my old Ibanez bass more authority down low.
When the focus changed to miking up individual drums I was pleasantly surprised by how well the 580 captured kick and snare sounds. The combination of the dbx’s fast transients with its -20dB pad and a little lift of the high detail EQ was an excellent combo. I found the low detail control sometimes added too much bulge to the sounds but a little touch could be helpful to bring out the weight of the kick in particular. For a few years now I’ve been using an older API 512B mic pre on kick (which I love for its fast transient response) but I could see myself swapping that out for the 580 on a regular basis. Finally, mention must go to the instrument DI which I really liked on bass guitar. Again the fact the EQ was always on hand to help tailor a sound was of great use here and I found my DI’d bass tones sat really well in a variety of mixes. In fact my only slight gripe with the unit was that at the high end of its taper the DI signal got a bit jumpy so small and careful gain adjustments were required.
CHIP OFF THE OLD BLOCK
Its hard to fault dbx on this one. They’ve kept the cost in comparatively cheap and cheery territory while delivering impressive sonic performance and a rich feature list that really adds value in many applications. While having a 580 preamp in your 500 series rack may not serve every purpose, the clarity and flexibility it offers on things like drum and percussion recording make it a winner in my book. Add to that its abilities as a sweet DI and as a versatile performer on guitars and bass and you’ve got a very handy addition to your studio.