Интегральные усилители — Heed Audoi OBELISK SI

The Obelisk Si is a compact modular integrated amplifier from Heed Audio of Budapest, the Hungarian company founded by the acoustics engineer Zsolt Huszti, and the DAC version adds a converter card that turns the first input into a digital one. Heed's first product under its own logo was the Obelisk integrated amplifier of 1993, developed with the late British designer Richard Hayem as a continuation of the Ion Obelisk of the 1980s. Before that, Zsolt and his brother Alpar had started Zsolt Audio in 1987 to import British brands such as Audiolab, Rega, Roksan and Spendor into Hungary. The current Obelisk Si III sells for CAD 4,599 or NZD 3,649 in its basic form.

Key specs that matter

Output is 50 W per channel into 8 ohm. The basic amplifier has five RCA line inputs with a sensitivity of 250 mV and an input impedance of 10 kOhm, and with the DAC card fitted one of them becomes an S/PDIF input. Outputs are one pair of speaker terminals and a tape output. The response spans 5 Hz to 60 kHz, and noise sits 96 dB below the signal. Maximum power consumption is 200 W. The amplifier measures 22 x 8.5 x 36 cm and weighs 6 kg.

Engineering and use context

The Obelisk Si uses Heed's capacitor-coupled TransCap amplifier principle, in which a capacitor links the output stage to the speaker. Its modular layout accepts upgrade cards, an MM phono card, the DAC 1.3 and the DAC 2.3, so the owner can add functions later instead of buying a new amplifier. The DAC 2.3 card uses a Wolfson WM8741 converter chip with an XMOS USB Audio Class 2.0 receiver at up to 24 bit and 192 kHz, supporting sample rates of 44.1, 48, 88.2, 96 and 192 kHz, and jumpers on the card set playback and system preferences. It costs about EUR 490 and also fits Heed's Thesis models. The simpler DAC 1.3 variant accepts a coaxial signal only. The power supply can be upgraded with the external Obelisk X2, which moves more of the supply out of the amplifier case. The Obelisk Si is sold in three versions, as a plain amplifier, with a DAC and with a DAC and a streamer. At 22 cm wide, the case is narrower than standard full-width components and fits on a shelf or desk.

Pairing

Efficient stand-mounts or small towers are the right load for its output, used in a room of about 20 m2. A CD transport or computer connects through the DAC card, and a turntable needs the phono card.

Alternatives

The Heed Elixir is the compact five-input integrated amplifier with a built-in MM phono stage and headphone amplifier.