CONRAD JOHNSON ET250S

Pre owned. In good condition. Shows light signs of wear. Supplied with manual and original packaging.

The Conrad Johnson ET-250S is a hybrid stereo power amplifier with an advanced design, belonging to the “Enhanced Triode” line and conceived to combine the power and control of solid-state technology with the timbral refinement typical of vacuum tube design.

The circuit is based on a configuration that uses a pair of 6922 tubes in the input stage, responsible for providing voltage gain and significantly contributing to the overall sonic character, while the output stage employs high-current semiconductor devices designed to ensure strong stability and a high damping factor, making the amplifier suitable for a wide range of loudspeakers.

The physical structure features a solid and imposing chassis with an aluminum front panel and design solutions that reflect the brand’s traditional construction approach, including upper sections dedicated to the tubes, protected by ventilated plexiglass elements that highlight its hybrid nature.

The ET-250S delivers a rated output power of 250 watts per channel into 8 ohms and up to 400 watts per channel into 4 ohms, placing it among the most powerful models in the range, just below the brand’s absolute reference designs.

Both the power supply and internal design are focused on maximum current delivery capability and the management of complex loads, ensuring wide and controlled dynamic reproduction with particular attention to stability even with demanding loudspeakers.

The design philosophy aims for a balance between musicality and control, with a sonic signature that combines the naturalness and fluidity typical of tube technology with a more solid and structured low-frequency response made possible by the solid-state output stage.

The amplifier’s performance is closely dependent on system synergy, delivering particularly strong results with easy-to-drive speakers, while with more complex or electrostatic loads it may reveal dynamic limitations related to system matching and component break-in.

The initial operating period is particularly important for fully expressing its sonic qualities, as the use of high-quality coupling capacitors requires a long stabilization time during which tonal character and dynamic response evolve significantly until reaching full maturity.

Overall, the Conrad Johnson ET-250S is a high-power, strongly characterful power amplifier capable of delivering top-level performance in well-matched systems, representing a hybrid meeting point between tube tradition and solid-state technology.

Technical specifications:

• Power: ET250S 250 W per channel (20 Hz – 20 kHz, THD ≤ 2%, both channels driven into 8 Ω); 400 W per channel into 4 Ω
• Power (MET150): 5 × 150 W (20 Hz – 20 kHz, THD ≤ 2%, into 8 Ω); 5 × 250 W into 4 Ω
• Input sensitivity: ET250S 1.85 V for rated power; MET150 1.5 V for rated power
• Frequency response (at 10 W): 20 Hz – 20 kHz ±0.25 dB
• Signal-to-noise ratio: 104 dB below rated power
• Input impedance: 100 kΩ
• Tube complement: ET250S 2 × 6922; MET150 5 × 6922
• Dimensions (W × D × H): 40.96 × 48.26 × 18.25 cm
• Weight: 29.5 kg