WA22 is a fully balanced, Class-A, all triode-drive headphone amplifier, featuring 6SN7 driver tubes, 6080 power tubes, and 5U4G rectifier.

* Included tubes: 1 pair of 6AS7, 1 pair of 6SN7, and 1 5AR4

* Tubes shown on the pictures are not included.

* AC power supply cord, interconnection cable are not included

* Shopping cart applies to the U.S. buyers only. International buyers please contact for shipping cost and payment instruction.

Technical Specifications:
• Headphones impedance : 8-600 Ohms
• Input impedance: 100 Kilo-Ohms
• Frequency response: 8 Hz - 50 KHz, -3dB
• Output: 810 mw with 6080, 2 watts with 7236 power tubes
• Signal/Noise: 92 dB
• THD: <= 0.3%
• External dimension: 7”(H), 12”(W), 10.5”(D)
• Weight: 25 pounds or 11.4 kg
• Voltage: AC 110/220V, 50/60 Hz

Standard Features:
• Point-to-Point wiring
• True balanced topology
• All tubes. No semi-conductors in the entire circuitry
• One 5AR4 [PDF] rectifier tube. Direct substitute: 5U4G
• Two 6SN7 [PDF] drive tubes
• Two 6AS7 / 6080 [PDF] power tubes
• DACT CT2 balanced stereo stepped attenuator
• One balanced XLR input
• One single-ended RCA input
• Two 3-pin balanced headphone output (left and right ch)
• One 4-pin balanced headphone output
• One single-ended headphone output
• High and low impedance switch

Power tubes upgrade:
Sylvania 7236 NOS 1963
Hand-pick matched pair $110 (2 pcs)

One of the best power tubes available for this amp. The 7236 vastly improves dynamic and soundstage. It has a very good speed, warm mid range, tight and deep bass. Buy and ship separately.

Driver tubes upgrade:
Hand-pick matched pair
Shuguang Treasure CV181-Z / 6SN7GT $320 (2 pcs) with 12-month warranty

Low noise, very high resolution, extended full frequency range. True "Treasure" as a result of Shuguang's 50 years of expertise in vacuum tube design and production.

Rectifier tube replacement:
Sophia Princess Mesh Plate 274B rectifier $150 (1 pc)
Wide open soundstage, full body, silky smooth, a great combination with the above tubes. Buy and ship independently.

Sophia Electric™ 274B tube is a premium rectifier tube for a 5U4/5R4/5AR4 direct replacement with 3X longer plate structure, thus it has a deeper, wider sound stage and even smoothier sound than Mullard 5AR4.