Hand-wired ESS DAC Tube Power Amp

The xDuoo A35 is a fully integrated vacuum tube amplifier built for two-channel listening systems. Its hand-wired analog circuit combines a 12AX7 voltage stage, dual 12AU7 driver tubes, and four matched EL34 output tubes in a traditional push-pull configuration capable of delivering 45 watts per channel. Integrated Bluetooth 5.1 connectivity, ESS DAC decoding, and infrared remote control support allow the A35 to function as both a classic stereo amplifier and a modern desktop audio centerpiece.

Classic EL34 tube amplification

The A35 uses a fully tube-based amplification design with one 12AX7 tube handling voltage amplification, two 12AU7 tubes driving the signal stage, and four EL34 tubes powering the output section. The push-pull EL34 topology delivers strong dynamics, natural vocal presentation, and controlled bass response while preserving the warmth and harmonic richness associated with traditional tube amplifiers.

Hand-wired point-to-point construction

Core signal paths inside the A35 use traditional point-to-point hand wiring to reduce unnecessary lead interference and maintain short copper signal routing. The carefully organized internal layout helps lower crosstalk and preserve stable channel separation while supporting a smooth and spacious stereo presentation.

Ultra-linear operation mode

The amplifier operates in ultra-linear mode for improved tonal balance, frequency extension, and output control. This configuration allows the A35 to maintain layered imaging and pinpoint detail retrieval while preserving the smooth tonal character expected from an EL34 tube amplifier.

Integrated ESS DAC decoding

An ESS ES9018K2M DAC provides onboard digital decoding with low distortion and high signal-to-noise performance. The integrated DAC section allows convenient connection to modern digital music sources while maintaining the amplifier’s analog tube-driven presentation.

Bluetooth 5.1 wireless playback

The A35 includes Qualcomm Bluetooth 5.1 support with SBC, AAC, aptX, and aptX HD codec compatibility. Get stable wireless playback with higher-quality Bluetooth audio streaming from smartphones, tablets, and portable music players.

Custom EI transformer design

Custom EI transformers use imported silicon steel cores and high-purity enameled copper windings to improve stability and reduce transformer noise. Vacuum impregnation and low-magnetostriction construction help suppress vibration and maintain a lower background noise floor during operation.

Audio-grade internal components

The amplifier uses carefully selected internal components including Japan-made filter capacitors designed specifically for tube amplifier applications. These components support stable power delivery, smooth tonal balance, and controlled low-frequency performance.

Protective circuit architecture

Built-in relay protection introduces a 60-second startup delay to allow the vacuum tubes to warm gradually before playback begins. Additional protection circuitry automatically guards against overload and short-circuit conditions to help protect connected speakers and internal amplifier components.

Durable chassis and remote operation

A reinforced metal chassis and dedicated shock-resistant tube structure help reduce vibration and electromagnetic interference during playback. Gold-plated terminals improve long-term signal reliability, while the included infrared remote control allows convenient adjustment from across the room.

Product highlights

• 45W per channel EL34 tube amplifier
  
• Push-pull tube output topology
  
• 12AX7 and 12AU7 tube stages
  
• ESS ES9018K2M DAC integration
  
• Bluetooth 5.1 with aptX HD support
  
• Hand-wired point-to-point circuitry
  
• Ultra-linear amplification mode
  
• Custom EI transformers
  
• Relay-based protection system
  
• Infrared remote control included

Specs

• Power output: 45W per channel into 8Ω
  
• Frequency response: 20Hz–60kHz (±3dB)
  
• Signal-to-noise ratio: 93dB (A-weighted)
  
• Channel separation: ≥63dB
  
• THD: ≤1%
  
• Input sensitivity: 300mV
  
• Input impedance: 100KΩ
  
• Output impedance: 4Ω, 8Ω
  
• Tube complement: 1×12AX7, 2×12AU7, 4×EL34
  
• Bluetooth codecs: SBC, AAC, aptX, aptX HD
  
• Inputs: CD IN, AUX1 IN, AUX2 IN, Bluetooth
  
• Power supply: AC 110V (100–120V) / 220V (220–240V)
  
• Power consumption: 232W
  
• Dimensions: 15.0 × 13.4 × 7.9 in (38 × 34 × 20 cm)
  
• Weight: 44.1 lb (20 kg)

What’s included

• xDuoo A35 integrated vacuum tube amplifier
  
• Pre-installed vacuum tubes
  
• Infrared remote control
  
• Power cable
  
• User documentation