Cayin HA300-MK3

The Cayin HA-300 MK3 is the third-generation evolution of Cayin's flagship 300B headphone amplifier, a pure Class A single-ended triode design that has been comprehensively upgraded with third-generation wide-bandwidth transformers, DUELUND coupling capacitors, a redesigned power supply architecture, and dramatically expanded headphone compatibility. Every unit ships with hand-matched tubes and 48 hours of factory burn-in. The 300B character, rich midrange, natural warmth, expansive staging, is more refined and capable than ever.

Type and Technology

Desktop headphone amplifier and speaker amplifier, single-ended Class A triode. Dual-chassis design with physically separated power supply to minimize magnetic interference. Genalex Gold Lion PX300B output tubes. JJ 6SN7 voltage amplification. JJ GZ34/5AR4 tube rectification (with broader tube rolling compatibility than the MK2). Third-generation wide-bandwidth EI output transformers developed specifically for this model. Custom toroidal power transformer with high-purity copper winding for lower magnetic noise. DUELUND coupling capacitors from Denmark. Gold-plated tube sockets. Point-to-point hand wiring throughout. Three impedance settings (Low, Mid, High). 60-second delayed soft start. JRC MUSES 72320V volume control with 41-step ALPS attenuator. Remote control. Speaker output terminals (4-8 ohm loads). Lock-and-release umbilical cable system connecting the two chassis.

Sound Character

The MK3 delivers what only a 300B single-ended triode can, a midrange of extraordinary density and tonal color, a soundstage of unusual three-dimensionality, and a natural musical flow that solid-state amplification cannot replicate. The upgraded transformer system and DUELUND capacitors add a new layer of resolution and control to the classic 300B character, making the MK3 noticeably more transparent and spatially coherent than its predecessor without losing the warmth that defines the platform. The dramatically lower noise floor, shockingly quiet for a 300B design, makes it genuinely compatible with sensitive IEMs as well as demanding planars.

Build and Finish

Redesigned dual-chassis with a fine sandblasted aluminum finish for improved wear resistance and reduced fingerprint visibility. New family-style protective tube cage. Removable cages on both chassis. VU meters on the amplifier front panel. Premium gold-plated tube sockets. 48-hour factory burn-in and hand-matched tube selection on every unit. Lockable umbilical cable between chassis for stable, low-loss power delivery.

Best For

Audiophiles who want the definitive 300B headphone amplifier experience with meaningfully improved noise performance, broader headphone compatibility, and the finest component quality Cayin has put into this platform, from sensitive IEMs to the HiFiMan Susvara and beyond.

What's in the Box

• Cayin HA-300 MK3 headphone amplifier chassis
• Cayin HA-300 MK3 power supply chassis
• Lock-and-release umbilical cable
• Genalex Gold Lion PX300B output tubes (hand-matched pair, 48hr burn-in)
• JJ 6SN7 driver tubes
• JJ GZ34/5AR4 rectifier tubes
• Remote control
• Power cable
• Spare fuses
• Documentation

Specifications