Review: Resolution Oct '03
By George Shilling
Mastering equalisers are a rare and exotic breed and SPL has pitched in to the market with its own take on the process. George Shilling meets an early example and proclaims it king of the parametrics.
THIS IS A MONSTER 4U rackmount weighing more than 18kg, with an external PSU that, although compact in size, weighs more than 4kg. This 5-band parametric is truly an incredible bulk – and the price tag is similarly enormous (UK £8795 + VAT). Justification comes not only with the explanation that all the knobs are motorised, but also that the internal circuitry and tolerances are quite extraordinary by any standards.
The equalisation circuitry is, of course, all-discrete Class A. But the special features include 124V internal operation (most pro gear is 15-20V) that enables a remarkable 150dB dynamic range and +34dB headroom. The most important resistors are subject to a tolerances of an exceptional 0.001%, with double thickness circuit boards with double-width tracks, and separate grounding tracks between signal pairs to eliminate crosstalk.
SPL has coined the name SUPRA to describe these components, and this unit is deemed to be the first in a range of products using such technology. The revival of the “transistor sound” starts here, says SPL.
Another remarkable feature of the PQ is the switchable bandwidth mode. Constant Q and Proportional Q switching is available separately for each band on each channel, effectively providing two completely different EQs within the one unit.
The rear panel includes XLRs for audio, and several D-type multipin connectors for Master/Slave operation of multiple units (for surround use or subgrouping), and a promised remote control panel. A fat multipin umbilical connects the power supply unit, the PSU includes the only power switch. When that is flicked, a cascade of relay clicks is heard, followed by the sound of all the motorised knobs turning towards their left-most position. The central panel illuminates from behind, showing the name of the unit. A four-character matrix display shows memory locations and related messages. All the buttons have a lightly-sprung feel. Some, but not all, operate relays, which click audibly when operated. When active they light up, but when inactive the lights go out and their legending is unreadable, despite claims in the manual that they stay dimly lit.
Operation, as a simple stereo EQ, is fairly straightforward. As well as Bypass buttons for each channel, each band features a separate Bypass button and a Constant Q button. There are conventional controls for Amplitude (+/-11.5dB, although this becomes only +/-2.5dB at the broadest bandwidth setting in Proportional Q mode) and these feature an expanded scale from zero to 2.5dB for precise adjustment. The frequency controls all cross over and feature very wide ranges, from lOHz at the bottom, up to 28kHz at the top. I won’t bore you with all the ranges, but to give an indication, the LMF band ranges from 35Hz, while the HMF goes all the way up to 16kHz, and, despite there being an MF band between these two, their available frequencies actually cross over giving plenty of opportunity to ‘double up’.
Bandwidth is variable between 0.1 and 3.7 in proportional Q mode, and 0.9 and 15 in constant Q mode, the last of these enabling very precise and tight tweaking. Sonically, the EQ is faultless, exceptionally clean, and easy to set up. It sounds truly wonderful, and powerful settings never sound unpleasant. The knobs feature dear pointers and, no doubt because of the motors, are quite stiffly damped.
Memory operation is achieved by scrolling through preset numbers with nudge buttons and pressing Save or Recall. An astonishing 800 memory locations is offered. Although the manual doesn’t warn of this, when recalling settings, you must wait until the ‘rcl’ indication on the display has reverted to the memory number before tweaking. (SPL says it has corrected the manual now and adds that during recall you only hear the unprocessed input signal as the PQ is set to bypass mode while changing a preset to avoid switching noises. Ed) When a setting is recalled, the knobs wind round to their correct positions and the relays click in or out as appropriate for each band.
The other useful function for the motors is the ability to link the channels for stereo operation. In Link mode, turning a knob on the channel set as master causes the other channel to follow. Using the right channel as master (as described in the manual) didn’t seem to work, with the motors resisting my attempts to move the knobs. (SPL says current Version 240H software solves this problem. Ed) And the linked channel’s buttons don’t dim, as claimed in the manual. (SPL says they now do! Ed)
The motors don’t exactly whizz about – it takes a good few seconds for a knob to travel around its range. Following recall of a preset, even though the Link button may be lit, it must be pressed twice to reactivate this mode. (Again SPL says this is now sorted Ed) The only other problem here is operational ‘finger trouble’ – 1 found it easy to find myself absent-mindedly trying to adjust both channels in Link mode.
Although it seems that my review unit was still something of a prototype, there are rumours of a recording version in development with greater amplitude ranges and without some of the memory features. Perhaps oddly, this unit lacks any shelving EQ modes. But with unparalleled sound quality, it can certainly be billed as the king of parametrics. Astonishing.
PROS
Ultra-clean; huge dynamic range; loads of recallable settings.
CONS
Not portable (!); gets very hot; Beta-version unfinished design features and manual discrepancies (Both now addressed by SPL in current Version 240H software. Ed).
Find out more about the SPL PQ |
