Усилители мощности стерео — Trafomatic Audio Evolution Elegance

The Evolution Elegance is a stereo tube power amp built by Trafomatic Audio. It produces 2 x 50 W with its output valves arranged in class AB push-pull and is housed in a single chassis measuring 450 x 320 x 195 mm with a weight of 22 kg. The European price for the pre-order version is EUR 5,130.

Key specs that matter

A source connects via one RCA socket or one XLR socket, while the speaker terminals provide 4 and 8 ohm taps. Input sensitivity is 2 V rms, and input impedance measures 100 kohm. Total harmonic distortion is 0.03 percent at 1 W and 1 kHz and 2 percent at full output. Frequency bandwidth extends from 10 Hz at -1 dB to 85 kHz at -3 dB, with 85 dB of signal to noise. Power consumption is 250 VA, with a mains selector for 230 V at 50 Hz or 115 V at 60 Hz.

Engineering and use context

Four 6550 output tubes, interchangeable with KT88, run in push-pull pairs, and four ECC82 double triodes handle the stages ahead of them. Overall feedback is limited to 6 dB. Trafomatic winds the output transformers on double C-cores and fits Solen fast capacitors in the audio circuit. The internal power supply relies on a 300 VA toroidal transformer, a C-L-C filter and Nippon Chemi-Con electrolytic capacitors. Unlike the EOS models, there is no separate power supply box, which keeps the whole amplifier on one shelf. The transformer rating sits above the consumption figure. Its case size and weight match the Elegance Evolution integrated, which also uses 6550 output tubes but pairs them with ECC81 and ECC82 valves and has a narrower specified bandwidth. Other members of the Evolution series include the Evolution One and Evolution Two integrated amplifiers and the Evolution Line One preamplifier. The relatively high input sensitivity figure means a preamplifier with some gain, rather than a purely passive attenuator fed by a low-output source, is the safer front end.

Pairing

The Trafomatic Evolution Line One preamplifier was designed as a logical extension of this power amplifier and connects through its RCA outputs, while the XLR input accepts balanced preamplifiers from other makers. With its moderate output the amplifier suits speakers of moderate to high sensitivity in a room of about 20 m2, and the output tap should match the speaker's nominal impedance.

Alternatives

The Trafomatic EOS Power Amp is a larger dual mono stereo power amplifier with an outboard power supply and four KT120 tubes for 2 x 100 W.