Joemeek SC4 DAD and C2 Compressors
To the casual reader, it must seem like there is a new Joemeek product almost every month, and perhaps that is not far off the mark. Far from resting on any laurels, Ted Fletcher, the man behind Joemeek, has continually sought to upgrade and improve existing products, as well as introduce new designs. Eagle-eyed Joemeek-spotters will have noticed subtle improvements to existing designs, with version numbers appearing on the back panels such as ‘V2.03’, as if they were software releases. Although the designs benefit from years of audio history and experience, Fletcher obviously sees his designs as a modern technological progression.
Now I’ll come clean: the SC4 and C2 are both green Joemeek compressors. But hey, why change a winning format? The brand has an endorsement list which reads like the ‘Who's Who’ of music and pro-audio. And as well as three floors and 14 employees working at Joemeek headquarters in Newton Abbot, Joemeek now has a factory in Scotland churning out units by the truck-load.
Oddly enough, the manual states that the SC4 IS an SC2 (the first Joemeek photo-optical Compressor), albeit one with numerous enhancements. The SC4 retains a similar sized 2U case, with useful front panel handles. On the back of the black case there are XLR analogue connectors in pairs of inputs and outputs. There is also a pair of TRS jack sockets providing insert send and return, not for left and right as might normally be expected, but Mid and Side which reveals a major new design feature for a Joemeek. Although Sum & Difference techniques are commonly used in broadcast, and were once popular with disc-cutting engineers, the circuitry to do this is rarely, if ever, built into studio outboard compressors.
When working with stereo material, the SC4 decodes the left and right inputs into sum and difference signals, not entirely dissimilar from those one might derive from a Mid/Side mic technique. These are then compressed separately, before being encoded back into normal stereo before the output. This system results in an unbeatably solid and stable stereo image, even with moving sounds and heavy compression. Apart from this major benefit, there are a couple of other bonuses. The aforementioned insert points can enable separate external processing of mid and side components, so why not auto-flange the ‘Side’ and filter the stuff in the middle, for example? The possibilities are endless, and can give you some unusual fun and inspiration. Another related feature is a continuously variable Width control on the front panel. This has a centre-détente for normal stereo, but can be rotated left into mono, or right to an enhanced-width stereo output, resulting in an apparently wider-than-your-speakers stereo image. On an entire mix this can be a little disconcerting, but used sparingly it can be very effective.
Unlike other outboard manufacturers, Joemeek has not released any Pro-Tools plug-in versions of its products. Ted Fletcher asserts that the exact characteristics of Joemeek analogue electronics cannot be accurately reproduced by DSP technology. Fletcher quotes frequency response up to 30kHz using the analogue connections, which is obviously unavailable digitally with a maximum sampling frequency of 48kHz. However, rather than ignore the burgeoning digital market, Fletcher has come up with a solution in the form of the SC4 DAD. With the addition of a digital board one can now directly interface with any digital recording set-up. By utilising high-quality 24-bit converters running at 44.1kHz or 48kHz, signal integrity is retained as far as possible within the limitations of the format. Digital connectors are provided on both AES/EBU XLRs and TOSLINK optical connectors, with a rear-panel pushbutton to switch from Consumer to Professional mode, necessary for interfacing certain devices. This will rarely need to be switched, but I would say that I think all buttons should be on the front of any device designed to be rack-mounted. An IEC socket includes a fuseholder, which is rotatable for voltage conversion.
On the front, legending is the usual black-on-green. Fluorescent orange would be better, but you soon learn where everything is. The biggest knob is the Input Gain on the left, with multiple soft détentes. On the far right the Output Gain is similarly knobbly. Next to the Input knob are two pushbuttons for Digital Input selection and M&S. The latter bypasses the decoding circuitry at the input stage, allowing you to input directly a Mid/Side signal. Attack and Release controls provide a wide range of compression characteristics, and like previous models there are no ratio or threshold controls. The familiar Joemeek system is used, whereby a Compression control boosts the signal to the photocell-compressor sidechain as it is increased. Ratio varies, continuously increasing as input level increases. The way this happens is determined by the Slope selector, now upgraded from the SC2’s four positions to five. These determine the rate of ratio increase to level. With the SC2, I found I rarely used Slopes 3 and 4, but this new array provides a little more control.
Slope 5 is completely ridiculous, with an almost inside-out effect achievable with some signals, i.e. the louder the input, the quieter the output seems. A compressor in/out pushbutton is provided, accompanied by two LEDs (one for in and one for out – just the one would have been enough.) Unfortunately, this is not a true ‘hard-wired’ bypass, but this fact is compensated for with a 2dB increase in gain when the compressor is in, making comparison slightly easier. The two VU meters were subjected to physical abuse from colleagues seeing the unit for the first time, and assuming them to be a stereo pair. No, the needle is not stuck(!), one simply shows Input signal level, and the other Gain Reduction, which is fine in use. Perhaps, though, they could have been positioned or coloured differently to look less like a stereo pair. Beside these is the aforementioned Width control. Near the Output Gain knob is a pair of pushbuttons for selecting digital sync (internal or external) and output sampling frequency (44.1kHz or 48kHz).
Samplerate conversion can be achieved easily, as the Input and Output converters are completely separate. An additional LED indicates the presence of digital sync. Sync is achieved within a second when switching frequency or sync source, and levels have been sensibly set in relation to the analogue connectors. When using digital connectors, all front panel gains controls are still operative. Using analogue connections in a normal professional environment, one seems to need the input gain set fairly low for a normal input level. However, this allows more gain for you to drive the compression harder, and it is virtually impossible to overload this unit or make it distort. It also means that operating in a –10dB environment is easy. The two gain controls have default marks, but these seem to be arbitrary, as at these settings there is a gain boost of several dBs.
In use, the compression is smooth and sometimes slightly deceptive. Unless the attack and release settings enable audible ‘pumping’, the compression can be surprisingly discreet. There is none of the graininess one associates with older valve designs such as Fairchild, and none of the loss of high frequency content that happens with most other compressors when compressing heavily. Even with the most ridiculous amount of compression, all that is achieved is level adjustment – tonal changes are subtle, and the full audio frequency spectrum is left intact. One often finds that there is a ‘sweet spot’ on the Compression knob where a certain threshold is crossed and the signal pumps a bit more, and I particularly enjoyed using the Joemeek gently on acoustic guitar and savagely for a wacky piano sound. It sometimes works well subtly over an entire mix, but is not always the best mix compressor: it is not designed as a levelling amplifier. The SC4 is, however, a smooth and clean performer, with a very low noise floor.
The baby C2 Compressor is a half-rack unit a fraction of the size (and price) of its big brother the SC4. However, at its heart is similar circuitry. It even uses similar M&S technology. Of course, many features are missing compared to the SC4, but the front panel Input and Output Gains, Compression knob and Attack and Release knobs all work almost identically. The gain structure is set up similarly, with a range easily encompassing –10dB and +4dB working environments. Slope is a function of input gain. The metering by LEDs is adequate, and the legending actually slightly better in some respects than the SC4. One has to suffer an external PSU and connectors on balanced º" TRS jacks, (no insert points or digital converters of course), but for the money this unit is superb, with no discernible difference in audio performance compared to the SC4.
Both these units have the unique Joemeek sound with the added stereo stability of M&S. They are not right for every signal, but with experience one can find numerous uses for them. As always, Fletcher’s manuals are an entertaining read, and one eagerly awaits the next instalment…
Reproduced with kind permission from www.George.Shilling.Com. Copyright ©