SW1X LPU I Phono Pre-Amplifier

SW1X Audio Design™ LPU I Performance Level 1 MM Valve Phono Pre-Amplifier

 

The phono pre-amplifier is based on a classic all valve circuit design used to master vinyl recordings and master tapes.

It is a two gain stage design consisting of 2 (one for each channel) pentode valves on the input and one double triode valve on the output.

The input stage utilises lush sounding EF86 valves in pentode mode, which are loaded by passive RIAA equalization network (series resistor-less, dynamics preserving), driving the powerful 6N6P or 5687 double triode on the output stage

 

SW1X Audio Design™ LPU I Features:

  • Specially Selected and Harmonically Matched Component & Material Quality
  • MM Phono Pre-amplifier is suitable for all moving magnet (MM)  or moving coil (MC) in combination with a matching SUT
  • Classic 2 Gain Stage Pentode Input-RIAA-Triode Output Design
  • Based on 2 x EF86 Pentode Valves on the Input and 6N6P/5687 Double Triode on the Output
  • Pure Class A, Zero NFB, Single Ended, all Valve Amplification RC (resistive loading/capacitive de-coupling) Circuit Topology
  • Passive Series-Resistor-less RIAA Equalization
  • PIO or Film/Foil de-coupling Capacitors in Inter- and Output Stage
  • 6X5 or 5Y3 Valve Rectified CLC2RC (choke filtered) B+ Power Supply
  • 47K Input Impedance & <1K Ohm Output Impedance
  • Total Gain is approx. 40-46 dB depending on the Choice of Valves
  • Maximum Input Voltage: 350mV
  • HQ, EI Core, 110/115/230/240V AC mains transformer

 

Optional Extras:

  • AN Copper foil, mylar in Oil Signal Output de-coupling Capacitors for Interstage and Output Stage
  • AN 2W copper, non- magnetic, tantalum film resistors on plates of the output tube
  • STD version of DAC II can be ordered with either US made 5687/E182CC or Soviet 6N6P Premium 6N6P from the 60s or Premium vintage NOS black plate Tung Sol 5687/E182CC output tube
  • Directly Heated 5Y3/GZ34 type of tube (from the 60s) in the PSU
  • Orient Grain, M6 EI Core, Copper flux banded, mains Transformer

 

M. Fremer’s Review of SW1X LPU I RIAA MM Phono is out on Stereophile

 

 

Note: Due to SW1X Audio Design’s ongoing research and development process, specifications are subject to change without notice.

Specifications

Dimensions: Height (mm) 140 x Width (mm) 340 x Depth (mm) 410

Weight (kg): 8.5

Max Power Consumption (W): 12

Output Noise, Unweighted (mVrms): < 0.5

Output Impedance (k Ohms): <1

Tube Compliment:  2 x EF86, 1 x 6N6P or 5687, 1 x 6X5 or 5Y3

Front panel options: brushed Silver or matte Black

 

Reviews and customer’s feedback can be found here  

 

Ordering

We do not recommend purchasing a key system component without first auditioning it carefully, which is why we have demonstration rooms and a 14 day trial period policy. However in certain situations it can be difficult for people to get to our showroom and for those instances we can offer our mail order service.

 

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