Интегральные усилители — Layer Audio Design (LAD) GEN-300B

The Layer Audio Design GEN-300B is a stereo integrated amplifier built entirely around vacuum tubes, with a pair of 300B triodes in the output stage running in single-ended Class A. The maker lists it at USD 1,499 and offered it on preorder with shipping scheduled for December. The company describes the design as one that leans on the natural linearity of the 300B rather than on correction schemes or layered circuitry, and it places consistency across the listening range ahead of maximum power.

Key specs that matter

Rated power is 10 W per channel into 8 ohm in pure Class A, and the rear panel offers separate 4 ohm and 8 ohm speaker taps. The tube complement consists of two 6N8P driver tubes, two 300B output triodes and a single 5AR4 rectifier. There is one RCA line-level input plus a direct power-amp input that bypasses the volume stage. A headphone jack is fitted to the fascia. The chassis measures 335 mm wide, 210 mm high and 265 mm deep, and each unit weighs 16 kg.

Engineering and use context

The GEN-300B uses discrete valve circuitry in every stage, with no solid-state gain stage in between. Rectification is also handled by a tube, the 5AR4, instead of silicon diodes. Layer Audio Design uses custom-wound Japanese transformers, Amtrans film capacitors matching those used in the ATH Narukami amplifier, and Cardas wire for the internal wiring. The headphone output is not a separate op-amp circuit - it is tube-driven and transformer-coupled, taken directly from the main amplifier circuit. An optional Bluetooth module can be ordered, described as electrically isolated so the wireless section stays apart from the analog signal. Buyers can also choose between several finishes, headphone output variants and an upgrade to Cuprum Isolation Feet, and the brand sells a COPULA headphone adapter made for this model. The direct power-amp input lets the GEN-300B serve as a pure power amplifier behind a separate preamp or any source offering variable output.

Pairing

With its modest output, Layer Audio Design states that the amplifier is optimised for high-efficiency loudspeakers, so sensitive two-way or horn-loaded designs with an easy load are the natural match, connected to whichever tap is closer to their nominal impedance. One DAC or streamer is enough to fill the analog input, and a source with a digital volume control can feed the direct input.

Alternatives

The Layer Audio Design GEN-2A3 is a second integrated model from the brand, built around the 2A3 triode instead of the 300B.