E.A.R./Yoshino 660 Compressor/Limiter
Esoteric [es–o–ter'ik], adjective inner; secret; mysterious; taught to a select few – This is the dictionary definition of the ‘E.’ of E.A.R. (Esoteric Audio Research), which says much about the philosophy behind the company and its designs. Tim de Paravicini’s company, which employs six people, has been producing its 660 valve compressor since 1984, yet total production totals only the low hundreds. So this is no upstart, cashing in on the recent valve technology boom that has mirrored the digital onslaught. de Paravicini has long been a champion of analogue and valve technology, his outspoken views springing forth to challenge the motivation and wisdom of high volume manufacturers. Meanwhile, his Cambridgeshire-based company quietly builds small quantities of EQs, compressors, tape recorders and suchlike, which are coveted by those ‘in the know’.
The 660 is a typical example of de Paravicini’s theory and practice. He designs equipment to sound good, and all other aspects take a back seat. Hence the unashamed duplication of the revered Fairchild 660’s model number and design features. de Paravicini has taken what he feels to be the best aspects of this design, improving and changing only where necessary.
For a mono unit, the rack space seems excessive at 3U, and this height makes the 10" or so depth seem shallow. Six valves are mounted on the back in a recessed cubbyhole. This makes servicing easy and keeps them away from other circuitry, but they are not completely safe here, as I found when someone tried to helpfully remove a unit from its box with their hand inside this recess! No major damage, thankfully… Inside, there is transistor circuitry for non-audio circuits such as power supply.
As well as XLR audio connectors, there is a jack socket to link two units for stereo operation, which was successfully utilised, thanks to Mr de Paravicini’s generosity in lending me two units. This is activated by a front panel toggle switch. As well as an IEC mains input, there is a useful IEC mains output, thus enabling the feeding of one unit from the other with the correct cable – a terrific idea for keeping things tidy. Why does nobody else do this?
The front panel sports a black anodised finish, and features a large, conventional VU showing gain reduction. The controls are presented in a row of odd, small switches and pots, with certainly more boffin-appeal than sex-appeal. The pushbutton power switch illuminates. There are locknuts on preset pots for meter balance (to adjust tubes’ current matching) and meter zero, so I didn’t touch those… In association with these is a three-position switch for balancing each half of the tubes – one can check all is well by making sure the meter reads zero in all three positions. Like a Fairchild, compression adjustment is done with the Input Attenuation pot and the Threshold.
The Input knob is perversely as tiny as the Fairchild's is huge. There is no legending or calibration, and the tiny knob is undamped. As a bonus compared to the Fairchild, there are two different threshold knobs on the E.A.R. DC Threshold varies the slope: at full anticlockwise the unit will gently compress, and at the opposite end it will hard limit at a 10:1 ratio. However, turning this control clockwise also has the apparent effect of raising the threshold, so in fact turning this control alone will give you less gain reduction as you turn it clockwise. This control is stepped with 11 positions. There is a soft high-frequency ‘ping’ on the outputs when you change this. The AC Threshold is a more conventional threshold control, which can be adjusted in conjunction for the desired amount of gain reduction. Attack and Release times are variable by a 6-position rotary switch, which will be familiar to Fairchild fans. Four different attack and release settings are available, while positions 5 and 6 give auto program-dependent release times. The manual recommends position 6 for classical music, with a very fast release for short peaks, and a very slow release for sustained high levels. Release times are helpfully listed on the front panel.
The manual is a fairly elementary affair, with charming hand-drawn circuit diagrams and a few misprints.
In use the 660 is smooth and warm, but with a clarity not associated with Fairchild units. de Paravicini of course boasts that his units are better than Fairchilds. They have input and output transformers of his own design, for wide bandwidth, and PCC189 triodes which are true vari-mu tubes that are long lasting and more easily obtainable than those found in Fairchilds. He is right, of course. But the grunge and magic glow of a Fairchild is yet to be convincingly replicated, so the real thing will still be coveted. But the E.A.R. is a very worthy performer, magically and unobtrusively smoothing vocals, guitars, pianos etc. For drums, one sometimes desires something faster, (in which case I would plug something else in). But mostly, where compression is required, all the niggles and foibles are quickly forgotten, as this is a slick and charming performer, second to none. Okay, except perhaps a Fairchild!
with kind permission from www.George.Shilling.Com. Copyright ©