Усилители мощности стерео — Burson Audio Timekeeper

The Timekeeper is a stereo power stage from Burson Audio, the Melbourne, Australia company, launched in June 2013 at USD 2,600, with a European price of EUR 1,900. It was built to the same footprint as the company's Conductor preamplifier and headphone amplifier, and Burson aimed the pair at listeners who want full-size electronics on a desk. A buyer can start with one stereo unit and later add a second Timekeeper, switching both to bridged mono for more output.

Key specs that matter

Rated output is 80 W per channel into 8 ohm in stereo mode, and a single unit bridged into mono delivers 240 W into 8 ohm. Total harmonic distortion is 0.03 percent at 1 kHz into 8 ohm, and frequency response is stated as 0 Hz to 50 kHz within 3 dB. At line level the noise floor sits more than 98 dB below signal. Input sensitivity is 240 mV with an input impedance of 20 kOhm. The case measures 265 x 255 x 80 mm and the amplifier weighs about 8 kg. Peak power draw is given as 300 W, and units were built for either 240 V or 110 V mains.

Engineering and use context

The circuit is an all-discrete Class AB design using bipolar transistors, with no integrated circuits in the audio path and no unusual topology. Each channel sits on its own board in a dual mono layout. Power comes from a custom 300 VA toroidal transformer feeding a linear supply with six capacitors totalling 40,000 uF of storage. Parts listed by Burson include Elna for Audio and Elna Silmic II capacitors and Vishay Dale military-grade resistors with 1 percent tolerance. The case itself is built from silver anodised aluminium heatsink sections, and a temperature-controlled fan at the rear helps cool the compact chassis. At the back are two pairs of RCA line inputs for stereo use, a separate RCA input and an XLR input reserved for bridged mode, plus two pairs of speaker binding posts. Because bridged mode takes either RCA or XLR signals, a source without balanced outputs can still feed a pair of bridged Timekeepers.

Pairing

Burson designed the Timekeeper as the power stage for its Conductor, which shares the same case size, and Burson states that the pairing supports both RCA and XLR systems. Burson presented the system as one that can grow from a desktop setup with a single stereo unit to a large-room installation with two bridged Timekeepers, one per speaker.

Alternatives

The Burson Timekeeper 3X GT is a later dual-mono stereo power amplifier from the company, delivering 110 W per channel into 8 ohm and 180 W into 4 ohm, with the first 30 W in Class A.