With five well-deserved Golden Ear awards already tucked securely under his belt, Ralph Karsten's Atma-Sphere MP-3 preamplifier is an easy pick for yet another. Although not yet formally reviewed in these pages, the MP-3 has been my preamplifier of choice for well over a year now. Designed to perfectly complement Atma-Sphere's line of OTL amplifiers (including the superb MA-1 Silver Edition reviewed earlier this year in issue 146), this more economical, single-chassis version of Karsten's flagship MP-1 preamp has proven to be a gratifying match with solid-state amplification as well.
The crystalline clarity, lavish inner detail and wholesale openness of the MP-3 are but a divine appetizer to the uniquely exhilarating sound which has garnered the Atma-Sphere OTL an almost cult-like following amongst a small, but loyal enclave of music lovers and high-end audio aficionados. Although not having the ultimate punch usually associated with a good solid state preamp, this rather utilitarian looking sleeper's dynamics, liquid ease and stunningly huge 3-D soundstage are refreshingly addictive.
I've also found the MP-3 to be a useful reviewing tool, as its sonic signature (and I do believe even the most "neutral" of components has one) interferes less with ancillary equipment than other preamps I've used. I'll have to admit, I'm not real keen on the "clunky" volume control (with 2dB steps of attenuation between "clunks" sometimes it's tough to adjust the volume level exactly where you'd like it) but if it means compromising the sonic integrity for something a bit more precise, I'll gladly learn to live with it. With significantly less (if any) hash, grain or other electronic artifacts to get in the way of the music, once you've lived with a purist component such as the MP-3, it's tough going back.
You'll need to use adapters, though, for single-ended operation, as the MP-3 is a fully differential all tube design offering balanced
(XLR) only inputs and direct-coupled output. Retailing at $3650 for the line stage only (phono adds $600), the preamp can be optioned
with Teflon coupling capacitors ($600 option with phono, $300 for line stage) and also a new proprietary regulation scheme ($600) for
the power supply.
Atma-Sphere MP-3 Mk II Preamplifier