The 12AX7 + FU-19 high-end tube amplifier delivers controlled and elastic bass without muddiness, transparent and ethereal highs with a touch of brilliance, and sweet, mellow midrange as rich and aromatic as aged wine. The entire frequency range is exceptionally balanced. Vocal positioning is precise, creating the illusion that the singer is standing right in front of you.
Product Features
- Compatible with CD players or computer audio sources (ensure the computer sound card has a line-out port; an independent sound card is recommended over an integrated one, as the latter may output approximately half the volume of a CD player).
- All tubes feature AC filament supply. Even when paired with 90dB sensitivity speakers, no audible hum is present—silence as if the unit were powered off.
- Utilizes a 12AX7-driven FU-19 Class A amplifier circuit, delivering 8W+8W output power. Ideal for speakers with 4–8 ohm impedance and sensitivity above 90dB.
- Volume control employs a Japanese ALPS 16-type potentiometer for precise channel balance and clear positioning.
- Precision 1% metal film resistors and imported electrolytic capacitors are used. Coupling capacitors are Hong Kong TE MKP film types, offering sound quality comparable to WIMA.
- Multi-stage CLRC filtering ensures high signal-to-noise ratio. Filter capacitors are Japanese brands like Nichicon or Chemi-Con, paired with high-power metal oxide film resistors and a 6H 0.2A inductor to form the CLRC network. The tube filaments are wired in a 3.15-0-3.15 configuration with center tap grounded for excellent hum suppression.
- Tubes include new-production Psvane ECC83 (equivalent to 12AX7) and Beijing FU-19, with a Shuguang 5Z4P rectifier tube.
- Custom-wound FU-19 (5K) 10W output transformer (model 664403) and 160W power transformer (model 965008), both made in-house for stable and reliable performance. The power transformer provides a full 160W with a 96x50mm core, remaining cool and vibration-free, and includes a top cover. The output transformer uses a 3+2 winding method with a 66x44mm core made from Japanese Z11 0.35mm thick silicon steel sheets, offering higher permeability and deeper bass compared to domestic H14 or H18 silicon steel. Transformers constitute the majority of the unit's cost, warranting special mention.
- Hand-wired point-to-point construction facilitates easier upgrades and modifications.
- Rated output power: 8W+8W per channel (thanks to tubes' strong overload capacity, the actual undistorted output is comparable to a 60W+60W transistor amplifier). The unit provides 4-ohm and 8-ohm output options. Best paired with high-sensitivity bookshelf speakers, ideally 6.5-inch models within 80W power handling. Operating in Class A across all stages, distortion is minimal, delivering sweet, smooth, and highly listenable sound.
Appearance & Dimensions
- Chassis material: Solid ash wood (not veneer, genuine solid wood with significantly higher cost than aluminum, iron, or stainless steel chassis).
- Product weight: Approximately 8.5kg
- Product dimensions: Width: 300mm, Height: 145mm, Depth: 20mm (including tube height)
Parameters & Performance
- Input: One RCA input
- Output: Two sets of speaker terminals for 0-4 ohm and 8 ohm
- Frequency response: 20–28kHz ±2dB
- Signal-to-noise ratio: >95dB "A"-weighted
- Total harmonic distortion: <1% at 3W output
- Reference schematic (component values based on actual parts; schematic is for circuit structure reference only):
