Усилители мощности стерео — YBA Signature Stereo Power Amplifier

The Signature Stereo Power Amplifier belongs to the Signature range of YBA, the French firm founded by Yves-Bernard Andre, and pairs with the Signature Mono version for owners who need a single-channel unit. It is a solid-state stereo amplifier whose case of natural aluminium shows no control buttons on the front, only an oval level indicator. The price in Australia is AUD 28,500.

Key specs that matter

Rated output is 200 W per channel into 8 ohms and 400 W per channel into 4 ohms in stereo mode, rising to 600 W into 8 ohms when the amplifier is bridged as a mono unit. Inputs comprise an RCA stereo pair, a balanced stereo pair and a separate balanced mono socket, and each channel has two pairs of loudspeaker outputs. Power comes from a linear supply with a 1,000 VA UI-Core transformer. YBA specifies signal to noise above 95 dB, a frequency range of 20 Hz to 20 kHz within 0.5 dB, and THD plus noise under 0.1% across that band. Standby consumption stays below 0.5 W. The chassis measures 430 mm in width, 390 mm in depth and 170 mm in height and weighs 42.5 kg.

Engineering and use context

YBA describes the circuit as completely symmetrical and says this cancels faults entering from the mains supply, minimises parasitic ground currents and removes the need for passive parts in the signal path. The signal passes through transistors only. A complementary double differential input stage comes first, followed by a pre-driver that adapts impedance and starts voltage gain. A third stage finishes the voltage amplification and supplies the current and voltage for the output stage, which is directly coupled to the loudspeakers. Circuit geometry keeps component spacing and internal wiring as short as possible, with only a few centimetres of wire at the input and at the output. The transformers hang in a suspended mounting so that less of their mechanical vibration reaches the rest of the chassis. Every Signature product ships with a certificate signed by the founder, and his signature is also placed inside the unit.

Pairing

Balanced and unbalanced stereo inputs let the amplifier follow either type of preamplifier, for example the YBA Signature preamplifier or a digital source whose level can be adjusted. Two pairs of terminals per side make bi-wiring possible without jumpers, and doubling into low impedance suits floorstanders with low impedance. Two units bridged in mono give each loudspeaker its own amplifier.

Alternatives

The YBA Passion A650 is a stereo power amplifier with the same power ratings and bridged mode, housed in a much lighter 25 kg chassis.