SW1X LPU II SPX

The SW1X LPU II SPX is the higher-gain sibling of the LPU I, sharing the same EF86 pentode input stage and mastering-studio circuit heritage, but with an inductively loaded output stage using 6N6P triodes and a CLC choke-filtered power supply that delivers improved output impedance, greater authority, and a more refined presentation for demanding cartridge and system pairings.

Type and Technology

Moving Magnet (MM) valve phono preamplifier, two-stage design. EF86 pentode input stage with active series-resistor-less RIAA equalization. 6N6P inductively loaded triode output stage, the key distinction from the LPU I's resistively loaded design. Pure Class A, zero negative feedback, single-ended all-valve amplification. LC topology with inductive loading and capacitive decoupling. Valve-rectified CLC choke-filtered B+ power supply (5Y3 rectifier). PIO or film/foil decoupling capacitors. 47k ohm input impedance. Compatible with any MM cartridge, or MC via a matching step-up transformer. Total gain approximately 50–52 dB depending on valve choice, meaningfully higher than the LPU I for lower-output cartridges. Available in satin Silver or matte Black.

Sound Character

More authoritative and refined than the LPU I, with the inductive loading of the 6N6P output stage providing a lower and more controlled output impedance. The higher gain makes the LPU II SPX particularly well suited to lower-output MM cartridges and those who need additional headroom in the phono stage without reaching for a separate step-up transformer. The EF86's characteristic lushness and openness remains fully intact throughout.

Build and Finish

Hand-assembled with specially selected and harmonically matched components throughout. Larger and heavier than the LPU I at 14kg, reflecting the more extensive transformer and choke complement. Optional upgrades available including fine silver wiring, fully hardwired tube output stage on Bakelite board, SW1X custom copper-wound Super HiB DC core signal chokes, silver foil capacitors, and AN 2W silver non-magnetic tantalum resistors.

Best For

Vinyl enthusiasts who want the EF86 phono stage character with higher gain and improved output stage design, particularly those with lower-output MM cartridges or systems that demand a more robust phono stage output.

Specifications