This is a fully balanced input and balanced output state-of-the-art pre-amplifier. It boasts an ultra high current tube rectified power supply, plus choke with NOS filter capacitors. A separate filament Tx and high-voltage Tx is also included to enhance the dynamics and clarity. This pre-amplifier is the low cost version of the QA-808 which is specially designed for those who like both an ultra sweet sound quality , with a very dynamic, musical, high definition detailed and deep sound stage.

The output buffer stage characteristics can change with over 10 different types of tubes: (6G6/6L6/6V6/6Y6/6K6/EL34/6550/KT66/KT88/KT90/KT100) for exact tuning to match the rest part of your system.

Now available is a super rectifier tube up-grade for the 5U4G, this can greatly enhance the dynamics, high and low frequency extension and bass punch, also boasting a stand-by switch for pre-heating of the rectifier tubes to ensure the longest lifetime operation. Rectifier tubes are replacable with high quality ceramic sockets installed.

The 5U4G tube rectifier can further upgrade by our super rectifier STR-104 or higher models , direct plug and play without any mod required.

With this super rectifier adaptor, you can use 300B, 2A3 , 45 , 50 , 80, 83, 1616 , 3B28 or 866A as rectifier tubes option.

(Note: The price quoted is a special deal for newly order unit only, modification of existing unit will be around $300 higher than the following prices due to more works for disassemble of the original circuits)

Level 1 upgrade : (FREE with new orders , limited time offer !! SAVE $200)

Special designed "Super-Drive" circuit, output impedance lowered to 200ohm (can drive any power amp inputs from 600ohm up to infinity) with better bass control and punch , better definition and improved in overall tonal quality. By adding this upgrade, it sounds like the output with 10 pieces of power tubes being installed . With this level of upgrade, just add another $50 and you can have a headphone output with enough power and current to drive your headphone directly.

Level 2 upgrade : (+ C$500)

Level 1 upgrade + Enhanced input circuit design with increase of max. input levels , further lowering of distortion and increase dynamics, as well as better air and openness . Enhanced components quality for better sonic reproductions with higher resoltuions.

Additional Upgrade option:

add 0/180 deg phase control switch with additional of C$150

solid-oak chassis add C$250

Super high gloss piano solid-oak finish add C$500

(optional chassis : Mirror steel, solid-oak )