Ypsilon of Greece has introduced the PST-100 MKII Stereo Preamplifier, a pinnacle in preamplification and a must-have component for building a no-holds-barred audio system.
The PST-100 MKII is a leading-edge tube preamp that uses two Siemens C3m triode tubes, which are rated for 10,000 hours or about 15 years of operation. It possesses exceptional tonal purity and superior dynamics, and projects a transparent, highly integrated soundstage that creates a you-are-there listening experience.
Preamplifiers are designed for a number of tasks: to draw together multiple source components, to attenuate the signal to achieve volume control, to provide low enough output impedance to drive the cables, and to provide gain if needed.
Conventional wisdom says the active circuit design is its most critical part. Ypsilon believes signal attenuation, or volume control, is the most critical element in a preamp's overall sound. As a result, Ypsilon developed a special transformer with 31 taps for the PST-100's signal attenuation. Produced in-house using the very best materials, Ypsilon's transformer attenuator produces an ultralinear magnetic circuit, for a boost in output power and a much more musical and detailed sound than conventional attenuators. The attenuator achieves a maximum attenuation of 52db, and is placed after the valve stage, preserving the purity and micro details of the signal.
Unlike Ypsilon, most preamp designers use resistor attenuators for volume control. A series resistor transforms the constant voltage into current, and a parallel resistor transforms the constant current into voltage. But Ypsilon believes the materials used in most resistors are far from ideal, and the sound is often noisy.
The PST-100's active gain stage is a no-feedback, transformer-coupled single-ended triode that achieves a maximum gain of 12 db. The power supply uses valve rectification and choke regulation. The latter, also known as choke filtration, contributes to an amazingly quiet background by preventing distortions in the capacitors from compromising the music signal.
The PST-100 can be operated in purely passive or active modes, which gives listeners the opportunity to maximize the purity and/or strength of the signal. Active mode is the default setting, while passive mode is recommended for use with source components with less than 3k-ohm output impedance. The PST-100's maximum output impedance is 150 ohms.
The PST-100 comes equipped with one XLR input and one XLR output, unbalanced, in addition to single-ended inputs and one single-ended output, and four pairs of RCA inputs. Custom-made pure silver wiring is used throughout, and a sturdy six-button remote control is included.
The PST-100 MKII Stereo Preamplifier is available now from authorized Aaudio Imports dealers at a suggested price of $37,000 (U.S. MSRP).