Усилители мощности стерео — Ampsandsound Stereo 17

The Stereo 17 is a valve stereo power amplifier from ampsandsound, the company founded by Justin Weber, based in Aliso Viejo, California. It was introduced at AXPONA 2026 in Chicago alongside the Kenzie Reimagined headphone amplifier and the Badlands preamplifier. It was priced at USD 6,000.

Key specs that matter

Output is 2 x 17 W in ultralinear mode. EL84 pentodes in push-pull form the output stage. The circuit is based on the Halfer design with cathode bias. The input stage uses a 12AX7, and the phase inverter a 12AU7. Input impedance is 500 kohm. Speaker taps are 4 and 8 ohms, with an 8 and 16 ohm combination as an option. The chassis is made from 11-gauge steel plate, and the amplifier weighs about 17.7 kg, heavy for its compact size. ampsandsound recommends speakers with a sensitivity above 92 dB, in small to moderate-sized systems.

Engineering and use context

The EL84 is a small power pentode, widely used in guitar and hi-fi amplifiers, and in push-pull a pair of them per channel delivers the amplifier's rated power. Ultralinear operation connects the screen grid to a tap on the output transformer, a compromise between pentode power and triode linearity. The 12AX7 provides high voltage gain in the input stage, and the 12AU7 acts as the phase inverter, splitting the signal into the two opposite-phase halves the push-pull output stage needs. The very high input impedance suits any source or line stage, including valve designs with high output impedance. ampsandsound designs its products around circuit simplicity and long-term serviceability. The company builds its amplifiers by hand in the United States and sources most of its components from domestic suppliers, including its top plates, chassis, transformers and circuit boards. Its stated approach avoids integrated circuits and silicon voltage regulators, relying on capacitors, resistors and diodes, so that the amplifiers can be serviced 15 to 20 years later. The company's aesthetic includes hand-finished solid wood. Weber also introduced the DAC 4.4 R-2R converter. ampsandsound's earlier amplifiers include the ST15.

Pairing

The Stereo 17 suits efficient loudspeakers in small and medium rooms. The Badlands preamplifier, a tube-rectified line stage introduced with it, is its matching partner.

Alternatives

ampsandsound's Stereo ST15 Special Edition is the brand's earlier compact stereo valve amplifier.