Предусилители — Ypsilon Electronics PST 100 Anniversary Edition

The PST 100 Anniversary Edition is a valve line preamplifier from Ypsilon Electronics, the Greek company founded 30 years before its release. It was developed to mark that anniversary and to improve on the PST 100 SE, and it had its world premiere at Audio Show Deluxe at Whittlebury Park in the UK on 22 and 23 March 2025. It belongs to Ypsilon's 100 Series.

Key specs that matter

The gain stage uses one C3m valve per channel, with a valve rectifier, as in the SE model. Volume is controlled by transformer attenuators wound on custom nanocrystalline cores. Silver-wound nanocrystalline transformers are used at input and output of the active gain stage. The internal wiring is point to point in ultra-pure silver. The power supply uses only film capacitors and a high-inductance double C-core amorphous choke filter. The display is new, with large characters and selectable colours.

Engineering and use context

Ypsilon's design approach centres on how the signal is attenuated. Most preamplifiers use resistor ladders for volume, even with high-grade Vishay resistors, but Ypsilon found that these left an imprint on the signal and developed its own transformer attenuators instead. A transformer attenuator changes level by selecting taps on a winding, so the signal passes through magnetic coupling rather than being dissipated in a resistor, and the source sees a load that stays consistent across settings. On the PST 100 Mk2, the attenuator offers 31 steps and a total range of 54 dB. The Anniversary Edition moves the attenuator to nanocrystalline core material, which has high permeability and low losses, improving linearity at low levels. The gain stage uses the C3m, a pentode originally designed for telecommunications, here in what Ypsilon calls an ultra-pure topology with transformers at input and output, which leaves the signal path free of capacitors. The power supply avoids electrolytic capacitors entirely in favour of film types, filtered by an amorphous-core choke. There are no printed circuit boards in Ypsilon's approach to the signal path, which is wired point to point.

Pairing

The PST 100 Anniversary Edition pairs naturally with Ypsilon's own power amplifiers, such as the Hyperion monoblocks. Its transformer-coupled output drives long cables and power amplifiers of varied input impedance.

Alternatives

Ypsilon's PST 100 SE is the previous version of the preamplifier on which the Anniversary Edition is based.