This is a fully balanced input and balanced output state-of-the-art pre-amplifier. The QA-808 boasts an ultra heavy current tube rectifier and a regulated power supply with NOS filter capacitors. A separate filament transformer and high-voltage power transformer enhances the dynamic range and clarity. This pre-amplifier is built with no compromise in component quality, and it's superlative sound can readily be heard in the delivery characteristics: very sweet and realistic rendition, with excellent dynamic range, musicality, high definition, and a very detailed, deep sound stage. The tube regulator stage acts to tighten up the bass punch without compromise. This pre-amp is suitable for any type of music reproduction, we feel it's performance is unsurpassed by competitor products in any price range.
The output buffer stage’s 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 of your system. There are two buffer tubes for each channel , so the combination can be 100 different types of sound.
The 3rd lowest set shows mirror steel chassis verison
The 2nd lowest photo set shows a version with our most advanced 99 steps convertible volume control.
The lowest photo set shows the -SE version with the following added features: ($8,380)
1. Balanced output transformer with XLR + RCA output
2. selectable choke power supply for maximum smoothness and sweetness , with by-pass switch
3. 6x Oil capacitors upgrade for sweet and airy sound
4. Western electric cloth wire upgrade
5. MDE micro-dynamic extraction circuit for all 6 signal tubes, make those very small information surface out from the original recording and become very vivid and alive, you can hear the real ending of a music note from every musical instrument without masking effect. This upgrade can further improve the S/N of this unit to extreme quiet background noise level with super flat frequency response.
6. Enhanced power supply which can drive maximum 4x KT120 or KT150 output tubes, give out very natural but super dynamics and control with extremely high density warm and rich sound
7. Level-2 upgrade included
Now available is a super rectifier tube up-grade for 5U4G, which can greatly enhance the dynamics, high and low frequency extension, and bass punch. Also featured is 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.
the preamp is amazing!
With Rock music the bass, definition, body and sound stage are much improved.
But with complex classical and choral music I cannot quantify the comparison. It is like comparing a pea to a watermelon.
You should really charge twice the money for your products - but please wait until I have finished buying my system.