Woo Audio Inc. Fully balanced Transformer coupled headphone amp WA22

Price: $1900 Color Black Silver * 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. Owner's Manual(PDF) Technical Specifications: Headphones impedance : 8-600 Ohms Input impedance: 100 Kilo-Ohms Frequency response: 8 Hz - 50 KHz, -3dB Output: 1500mw @32 ohms, 700mw @600 ohms Signal/Noise: 92 dB THD: = 0.3% External dimension: 7â€(H), 12â€(W), 10.5â€(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 $120 (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 Sylvania VT231 NOS tubes We tested these tubes in an actual amplifier to ensure the highest quality. $300 (2 pcs) with 30-day warranty. You get a clean and dense sound image with these tubes. It is very low noise, smooth and delicate in the upper frequency range, deep and solid bass, high clarity. Rectifier tube replacement: Sophia Princess Mesh Plate 274B rectifier $160 (1 pc) with 30-day warranty Wide open soundstage, full body, silky smooth, a great combination with the above tubes. Buy and ship independently. Sophia Electricâ„¢ 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.