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.
Conventional wisdom suggests that the most critical part of a preamplifier is the active circuit design. We, 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. We have used resistor attenuators with high quality resistors (Vishay, in the past, felt unsatisfied from the character they induced in the signal. We developed a very special transformer as the means of attenuation, using special winding techniques and highest quality wires and cores. Its performance suppassed that of the best resistor attenuators. In a transformer 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. A transformer attenuator with 31 taps is used in the PST100 mk2 providing a total attenuation of 54db in its lowest tap.
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 gain is 16db. Output impedance is 150 Ω max. PST 100 mk2 is the pinnacle in preamplification. It is a must have component for building a “no holds” system.
PST 100 TA 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