Усилители мощности стерео — Hegel H20

The H20 is a stereo power amplifier from Hegel, the Oslo company founded by Bent Holter in 1988. Its core design comes from Hegel's H30 reference amplifier, and it uses the company's patented SoundEngine error-correction modules in a dual-mono layout in an anodised aluminium chassis.

Key specs that matter

Hegel rates the H20 at more than 200 W per channel into 8 ohms, dual mono, and peak current exceeds 130 A. Frequency response deviates by less than 0.2 dB from 20 Hz to 20 kHz, and phase deviation is below 2 degrees over the same range. Signal-to-noise exceeds 100 dB, crosstalk is below -100 dB, distortion is below 0.006% at 100 W into 8 ohms and intermodulation below 0.01%. The damping factor exceeds 1000. Input impedance is 10 kohm balanced and 50 kohm unbalanced. The chassis measures 120 x 430 x 370 mm in height, width and depth, with a weight of 25 kg.

Engineering and use context

Hegel's SoundEngine is a feed-forward correction technique. It measures distortion created in the output stage and cancels it before it reaches the speaker, without relying only on global negative feedback, and the modules in the H20 are laser-trimmed. The input stage uses Hegel's FET technology. The power supply is a 1000 VA dual-mono design with 90,000 uF of filter capacitance, feeding an output stage of 20 high-speed bipolar transistors rated at 15 A and 200 W each. The high transistor count and large supply explain both the peak current and the very high damping factor. The front panel alone contains more than 1.5 kg of aluminium, and the top and side covers share its bead-blasted finish. Two pairs of heavy gold-plated speaker terminals allow bi-wiring. The amplifier draws about 60 W when switched on without signal. Hegel builds it in black only, and the single front button handles power, while all other control stays with the preamplifier. Because the H20 has no volume control, it is meant for systems where the gain is set upstream, for example by a preamplifier, a DAC with volume or a streamer with a variable output.

Pairing

With its high output and firm control of the drivers, the H20 suits large, low-sensitivity floorstanders and speakers whose impedance dips low. The balanced input is an easy load for any preamplifier with XLR outputs, including Hegel's own P30A, and its full-width chassis fits standard equipment racks.

Alternatives

Hegel's H30A is the larger reference power amplifier that can also be bridged to a mono configuration.