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.