ZH270

About the ZH270

The David Berning ZH270 is a stereo power amplifier that employs patented radio-frequency switching power conversion technology to transform the high-voltage, low-current output tube impedance into a high-current, low-voltage speaker impedance. This unique approach eliminates the limitations of conventional audio transformers, allowing for very high impedance transformation ratios (16 k ohms plate-to-plate into 4 ohms, or 32 k ohms into 8 ohms). The amplifier delivers 84 watts per channel into 8 ohms with a frequency response from 1.5 Hz to 60 kHz and total harmonic distortion of 0.2%. It features a special triode-connected screen-drive arrangement for enhanced reliability and linearity at low idle currents. The ZH270 offers excellent tonal clarity, dynamic contrast, deep tuneful bass, and a spacious 3-D soundstage with superb transparency and image palpability. It includes a three-position feedback switch, low negative feedback, no phase compensation, and a fully regulated resonant-type switching power supply with advanced noise suppression and protection features. The amplifier weighs about 10 pounds and has a compact footprint with a black anodized aluminum finish. It is designed for use with speaker loads from 4 to 16 ohms and operates with low idle plate dissipation for long tube life. The ZH270 is noted for its immediacy, speed, and ability to reproduce bass frequencies down to 2 Hz at full power, making it a standout in tube amplifier design.