Интегральные усилители — Goldmund TELOS 670

The Telos 670 is an integrated amplifier from Goldmund, the Geneva-based electronics maker, combining a preamplifier, a power amplifier and built-in digital inputs with an internal DAC. It uses Goldmund's Telos Class A/B technology, which the company says it has refined over forty years, and many of its parts are made exclusively for Goldmund. The Telos 690 and Telos 790 sit alongside it as larger integrated amplifiers in the same family.

Key specs that matter

Output power is 2 x 215 W RMS into 8 ohm at 1% THD according to IEC 60065, and rated consumption at one eighth of full power is 250 W. THD+N is below 0.08% from 20 Hz to 20 kHz at 30 V RMS unloaded, and intermodulation distortion is below 0.02% SMPTE. Output noise is below 10 µV, dynamic range is 100 dB and maximum output is 170 V peak to peak unloaded. Gain is 35 dB, and the damping factor is 600 at 1 kHz into 8 ohm. Inputs are five analogue RCA pairs, USB Audio Class 2.0 up to 384 kHz and 32 bit with DSD64 and DSD128 over DoP, one Toslink and one 75 ohm coaxial S/PDIF input. Maximum input is 1 V RMS for analogue and -6 dBFS for digital. Two 300 VA toroidal transformers and a 13,600 µF capacitor bank make up the power supply, for 115 or 230 V mains. The amplifier measures 440 x 160 x 395 mm and weighs 24.5 kg.

Engineering and use context

The Telos circuits separate low-current and high-current sections, so the small-signal stages are not disturbed by the currents flowing in the output stage. The 9 mm aluminium casing and a 30 mm thick radiator chassis work as a passive heat sink, so no fans are needed, and the enclosure forms a Faraday cage that shields the circuits from external interference. Conic feet support the chassis. The joint-free case is micro-blasted grey aluminium, with black available on request. Integrating the DAC inputs means a computer, CD transport and television can connect directly without an external converter, while five analogue inputs cover line sources and an external phono stage. An RS232 port allows integration into control systems, and one pair of speaker binding posts is fitted. A damping factor of 600 indicates a low output impedance and firm control of the loudspeaker drivers.

Pairing

With its power reserve, the Telos 670 has the power for most loudspeakers in a room of about 20 m2 or larger. Digital sources plug straight in, while records need a separate phono preamplifier feeding an RCA input.

Alternatives

The Goldmund Telos 690 is the larger integrated stereo amplifier in the same Telos family.