SW1X PRE III Line Pre-Amplifier

SW1X Audio Design™ PRE III Performance Level 3 Line Pre-Amplifier

 

Essentially, the design of PRE III valve line pre-amplifier is akin of a power amplifier, which instead of driving high load of a speaker drives line level output. The PRE III line pre-amplifier utilises 6N6P or 5687/E182CC as a driver and a pair of triode connected EL84 is a classic power valves, which were popular in electric guitar amps and most radios in the 50s and 60s and is known for its articulate character. Altogether, the combination of powerful driver and output tubes & Signal Output Transformer (OPT) results in tonal purity, incredible transparency & the dynamic driving ability, which in turn provides an added dynamic expressiveness as the ability to dig deep into musical presentation. In combination with finest materials & component, the sound of the PRE III is transparent, characterised by scale, authority and dynamic bite.

The PRE III is a near unity gain, zero negative feedback (global or local) line pre-amplifier with a signal output transformer (OPT) de-coupled valve output stage. Signal OPT of highest quality not only increases transparency (superior to any kind of capacitors) but also lowers the output impedance of the line pre-amplifier further close to 4 Ohms, capable of driving any load of power amplifier input. That virtually unlimited driving capability of PRE III (as well as the DHT version PRE IV) line pre-amplifier acts as a supercharger to a source (DAC Phono, Tape or Radio). It is a great enhancement to any tube power amplifier, driving a sources (DAC or Phono), which has a weaker small signal (high output impedance) tube based output stage. With a help of of a PRE III, any source becomes unleashed to drive subsequent power amplifiers to its full potential.

Available with either M6 EI core, all Copper or Copper/Silver wound Double C-core Super HiB Signal OPT (Special version) or with the all Silver wound Ultra HiB for limited production Signature version. The option of a Phono pre-amplifiaction stage is also available in the forthcoming PRE III LPX version.

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SW1X Audio Design™ PRE III Line Pre-amplifier Features:

• Specially Selected and Harmonically matched Component & Material Quality
• Anode follower, zero NFB, Signal Output Transformer (OPT) de-coupled Valve Output Stage
• SW1X Audio Design™ Double C-core Super (Cu/CU or Cu/Ag windings) or Ag/Ag wound Ultra HiB Signal OPT transformers
• 1 x Double triode 6N6P or 5687 driver, 2 x EL84 Triode Connected Power Pentode Valve Amplificaton Design
• 2 x SW1X Audio Design™ Mono, 24 Way, discrete resistor Stepped Attenuators made from the Finest Materials and Specially Selected Resistors
• 5Y3/5U4GYB/5R4GYB Directly heated Tube rectified CLC2LC (choke filtered) B+ power supply
• For maximum transparency & dynamics, the circuit is hard wired with of a specially selected conductors (single strand or Litz)

 

Tube Compliment:  2 x EL84, 1 x 6N6P or 5687, 1 x 5U4/GZ32

 

Optional Extras:

• Fully Hardwired Tube Output Stage on the Bakelite Board
• Fine Silver wiring on the Input, Bakelite Board and Output
• SW1X Audio Design™ Custom Designed & Fully or Partly Silver wound Super HiB DC core Signal Output Transformers
• Black Gate VK capacitors in the B+ power supply
• AN 2W non-magnetic Niobium resistors on a Hardwired Bakelite Board
• Super HiB double C-Core mains transformers for the digital and DHT/DHD power supplies
• Silver Foil capacitors Inter-stage signal de-coupling capacitors

• AN 2W copper, non- magnetic, Niobium film resistors on plates, cathodes, power supplies
• AN Silver Foil capacitors in inter-stage and ouput stage signal decoupling option
• Circuit is normally wired with specially selected copper but can be ordered with fine silver wiring (including power inlet)

 

 

 

 

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

Specifications

Dimensions: Height (mm) 150 x Width (mm) 440 x Depth (mm) 400

Weight (kg): 17 (with LPX Phono, 22kg)

Max Power Consumption (W): 180

Output Noise, Unweighted (mVrms): < 0.5

Output Impedance (Ohms): 4

 

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