OPA-3A 300B Vacuum Tube Amplifier Original Aural Audio Valve Amplifier

Rated output power: external speaker output: 8W+8W ( 4-8Ω load)

Balanced earphone output: 4500MW+4500MW (32Ω load)

Single-ended earphone output: 1000MW+1000MW ( 32Ω load)

Whole machine frequency response: 20Hz~50KHz (-15dB)

Harmonic distortion: 0.5% (1kHz)

Signal to noise ratio: 89dB

Input sensitivity: 220mV

Input impedance: 100kΩ

Left and right output balance: <0.5dB

Use vacuum tube: 12AU7x2, 300Bx2, 5U4Gx1

Overall size (WXDXH): 360mmx275mmx170mm

Net weight: 20kg

Working conditions: Temperature: O℃~40℃ Humidity: 20%~80%

Storage conditions: Temperature: -20°C~70°C Humidity: 20%~90%

Earphone output mode is variable pressure output：

Output impedance: speaker 6Ω/earphone 64Ω

Output impedance when earphone balanced: 64Ω /6.5 output 32Ω

Vacuum tube 300B and 5U4G use Hengyang, 12AU7 uses shuguang

Product feature:

1: The whole machine adopts high-quality PCB welding to ensure stability and consistency

2: Two EI type output transformers with high-quality broadband response and high-quality Japanese Z11 iron core

3: Use high-power Z11 iron core EI power transformer specially designed for this machine

4: The high voltage part uses 274B/5U4G as the rectifier

5: Pre amplifier uses two 12AU7 vacuum tubes,

Power amplifier uses two 300B vacuum tubes for class A single-ended power amplification.It fully reflects the delicate, smooth and transparent personality unique to 300B.

6: Input has BALANCE/RCA selection

7: Earphone output can choose 4-core balanced output and 6.5 head output

8: With external speaker function

9: Boot mute delay function (about 30 seconds)

10: The power input uses FurutechFI-03 with insurance power tailstock

11: The power switch uses the British RS silver-plated contact power switch

12: The signal input uses the original American CARDAS/RCA signal socket

13: The volume potentiometer uses the original British AN audionote

14: Easy-to-install plug-in Vacuum tube protective cover