PST - 100 is most certainly an impressive addition to YPSILON's 100 series.
It approaches the concept of pre amplification in an outstanding way. Its heart lies in the in house made transformers used for attenuation. In addition its valve state circuit combined with exquisite materials produce the finest and most elegant sound that any pre amp could ever achieve.
Most manufacturers develop a circuit for their power amplifier and then use the design for their preamplifier. The raison d’etre of a power amplifier is to amplify the signal and drive the loudspeakers. That of a line preamplifier is to draw together the various source components; to attenuate the signal in order to achieve "volume control"; to have low enough output impedance in order to drive the cables; and finally, to provide gain if it is required. It performs totally different duties to those of a power amplifier and needs to be designed in a totally different manner.
Conventional wisdom suggests that the most critical part of a preamplifier is the active circuit design. Ypsilon, however, believe that the means of signal attenuation (the volume control) is the most critical to the overall sound of a preamplifier. Most designers use resistor attenuators for volume control. Ypsilon themselves have used resistor attenuators with high quality resistors (Vishay, Holco, tantalum types etc.) in the past, but that was before they developed a very special transformer as the means of attenuation. It was immediately apparent just how grainy and discontinuous resistors sound, even the best of them. The short explanation of this observation is that the series resistor transforms the constant voltage into current and the parallel resistor the constant current into voltage. The materials used in resistors are far from ideal as conductors- they sound much worse than pure copper or silver- and they do a lot of harm to the signal.
In a transformer, however, the magnetic circuit can be ultra linear when the very best core materials are used. The sound of such materials is much more musical and detailed compared with the best resistors. So Ypsilon produced, in-house, a special transformer attenuator with 31 taps.
The active gain stage is a no - feedback s.e. ,C3m triode, transformer coupled. The power supply uses valve rectification(using the 6CA4) and choke filter. Wiring is point to point with custom made pure silver wire. The transformer attenuator is placed after the valve stage, preserving the purity and micro details of the signal.
The maximum attenuation is 52db and maximum gain is 16db. Output impedance is 150 Ω max. PST is the pinnacle in preamplification. It is a must have component for building a "no holds" system.
PST 100 TA (16.650€)
PST 100 is also available without the valve stage for systems that don’t require additional gain. This version is equipped with the transformer attenuators and is called PST 100 TA. Notice that it is fully upgradeable to the full version at any time by returning to factory