Charter Oak 2 - S600 Overhead Mics 2000s silver and black matched pair- with flight case

With good looks and a unique sonic character, there's plenty to commend these mics. Charter Oak are relatively new microphone producers, having formed only five years ago, in 2002. The business is based upon sourcing component parts from around the world (mainly China), then hand-assembling them in Connecticut in the USA, and tailoring the complete system to provide a 'boutique' quality high-end sound. One of the key differences between the Charter Oak mics and their source Chinese designs lies in the choice and quality of electronic components — especially the selected valves and capacitors — which have a significant effect on the sound quality, even if they don't necessarily show in the technical specifications. The S600 is a very chunky, end-fire, large-diaphragm, cardioid valve microphone, and is supplied only in matched stereo pairs, in a sturdy, lockable metal attaché case, complete with dual-channel power supply, cables, and a pair of shockmount cradles. The mic itself measures roughly 210mm in length and 40mm in diameter, and weighs about 590 grams, so this is a substantial item! Its body is finished in a highly polished piano-black, with anodised capsule grille and integral wire-mesh screen. At the base of the mic is a threaded XLR stem, which fits into the rotating collar of the shockmount. The seven-pin XLR connection accepts power from the supplied PSU, and provides the audio output through that unit in the usual way. Etched on the body is the mic's serial number, along with the Charter Oak logo, but there are no other facilities: no filter or pad switches, for example. The capsule is a traditional one-inch, side-terminated design with a Mylar diaphragm, sputtered with a six-micron layer of gold. A frequency response of 18Hz to 20kHz is quoted, but no limits are given. The frequency response charts supplied with the mics show a pretty flat response, but not as flat as the generic trace published on the company's web site. They were both within a couple of dB from 60Hz to 7kHz, with a modest resonant peak at about 9kHz, above which the level falls off gracefully. The matching of the two mics is very close indeed, with only a minor discrepancy around 5kHz on the review models, so there are no problems there. The mic has a pronounced proximity effect if used closer than about six inches. Sensitivity is given as 13mV/Pa, which is quite healthy, but the self noise is a surprisingly high 22dB A-weighted. For comparison, the Neumann M147 cardioid valve mic has a self-noise of 12dBA. Maximum SPL for the S600 is 125dB for 0.5 percent distortion, which means that it will cope with most musical sources, even with close placement. Unusually for a large-diaphragm mic, the S600 is an end-fire design: you have to point it at the source, instead of facing the side to the source like a U87 or C414. This looks very odd when mounted in the traditionally designed, elasticated shockmount — although it seems to work well enough. This is an American-built mic, and the stand adaptor with the review models had a 5/8-inch thread; no 3/8-inch European adaptors were supplied. The knuckle joint is tightened with a large butterfly bolt, which proved able to tighten securely and release easily during testing. The power supply is a large, black, metal brick, with IEC mains inlet, illuminated power switch and voltage selector on one end, and two pairs of mic-in and signal-out XLRs at the other.