Monday 6 November 2023

SJS Arcadia Model 10 PSE 300B mono power amplifiers

This SJS Arcadia Model 10 power amplifiers are all about pairs. A pair of Premier level mono amplifiers, each using a pair of 300Bs in parallel to provide 20W of audio output power, using a pair of nano-crystalline core interstage and output transformers, and a pair of double C-core power supply chokes.

The Model 10 uses a NOS Sylvania 7N7 input valve to drive a 300B valve used to drive the parallel 300B output valves via an interstage driver transformer. The combination of 300B to drive 300Bs gives an effortless sense of scale, tone and clarity to help bring out the sense of the musical performance.

In common with other SJS Arcadia amplifiers it has been specifically engineered for sonic performance rather than technical specification, and fulfills SJS Electroacoustics primary design criteria:
  • Single Ended circuit topology
  • Pure Class A operation
  • Zero negative feedback
  • Valve rectification and choke smoothed HT power supply
  • Custom made HT T-network power supply capacitors with silver leads
  • Separate mains transformers for HT and filament supplies
  • Point-to-point circuit wiring without PCBs
  • Star-earth & star-supply wiring
  • Hand built
  • Real solid wooden frame
  • 4mm aluminium panels, black or natural anodized
  • Soundcare SuperSpike feet
  • Very low noise for use with high efficiency loudspeakers

This Premier version includes:
  • Nanocrystalline core output transformers
  • Nanocrystalline interstage driver transformers
  • Double C-core power supply chokes
  • Choke input power supplies
  • Fixed bias output valves
  • Self-biased driver valve
  • Hand made ptfe valve bases
  • Duelund CAST DC Silver foil coupling capacitors
  • Duelund CAST DC Silver foil bypass capacitors
  • Tantalum film resistors
  • Pure silver wire for all point to point connections

Delivered with solid walnut frame, black anodised aluminium panels and the dark grey transformer covers can be heard on demonstration at Definitive Audio in Nottingham alongside the rest of the SJS Arcadia range of amplifiers with Living Voice loudspeakers.