Alpha2delta PS1 tube phono stage: Lundhl transformers, Jupliter wiring and Charcroft capacitors

British firm Alpha2delta Audio has released the flagship PS1 tube phono stage. The leader and chief designer of the company, Jessica Kinchin (Jessica Kinchin), proposed a device in a brutal design. The PS1 phono stage was supplemented with the PSU1 power supply, which is decorated with a chrome-plated cylindrical transformer body. The two modules are interconnected by cables with DIN connectors – they supply 6.3 V and 280 V.

The PS1 phono stage is available for MM (Moving Magnet) or MC cartridges. The latter option is implemented by adding Lundhl LL1931 step-up transformers with switchable gain of 18/24 dB to the circuit. Signal switching is based on silver plated RCA connectors from CMC and XLR from Switchcraft.

The circuit, assembled in a dual mono zero-feedback configuration, uses a passive RIAA filter on Charcroft silver-mica capacitors.

The active part is powered by selected tubes – 12Ax7 high voltage double triodes used in the 6072A (12AU7) and ECC81 (12AT7) preamplifiers.

All internal signal wiring is solid silver Jupliter wire. With a gain of up to 42 dB, the PS1 claims channel separation and a signal-to-noise ratio of 120 dB.

Besides black, the PS1 phono stage and PSU1 power supply are available in other colors. This handcrafted kit costs £4,000 in the UK.