The 2A3

The 2A3 has always been a reference tube for listeners who value clarity, balance, and control.

Compared to higher-power triodes, the 2A3 operates with lower plate dissipation and simpler operating conditions. This allows it to remain linear with less stress, lower noise, and fewer demands on the surrounding circuit. When used correctly, it produces a sound that is direct, open, and unforced.

Circuit Architecture

The GEN-2A3 uses a fully discrete, all-tube signal path.

• Driver stage: 2 × 6N8P

• Output stage: 2 × 2A3

• Rectification: 1 × 5AR4 tube rectifier

Signal and power paths use carefully selected components throughout, including Amtrans film capacitors — the same series employed in ATH’s Narukami amplifier — along with custom-wound Japanese transformers and Cardas internal wiring.

Transformers, Power Supply, and Layout

Transformers and power delivery are treated as a single system.

The GEN-2A3 uses custom-wound EI-core transformers designed specifically for single-ended Class A operation. They are sized conservatively and run well below saturation to maintain thermal stability and predictable behavior. Power delivery is choke-filtered, prioritizing current stability and low noise.

High-quality capacitors and thick gold-plated components are used throughout the signal and power paths. The stainless-steel chassis and thick machined aluminum panels provide a rigid, quiet structure, while the internal layout is organized around heat flow, transformer isolation, and long-term serviceability.

Inputs and Operation

The GEN-2A3 may be used either directly from a line-level source or as a dedicated power amplifier when paired with an external preamplifier via a direct input path.

An optional Bluetooth version is available for systems requiring wireless playback. The wireless module is electrically isolated from the analog circuitry.

Specifications — GEN-2A3

Type Single-Ended Class A tube power amplifier

Output Power 5 W per channel into 8 Ω (Pure Class A)

Output Tubes 2A3 × 2

Driver Tubes 6N8P × 2

Rectifier Tube 5AR4 × 1

Inputs RCA line-level input, direct power-amp input

Optional Input Bluetooth (wireless module electrically isolated)

Speaker Outputs 4 Ω / 8 Ω

Headphone Output Front-panel headphone output (tube-driven, transformer-coupled)

Internal Wiring Cardas internal wiring throughout signal and power paths

Dimensions & Weight

Height 8.25" (21 cm)

Width 17" (43.2 cm)

Depth 10.4" (26.5 cm)

Weight (each) 36 lbs (16 kg)