Soulnote introduces A-2 ver.2 in three-amplifier update

Soulnote has introduced revised versions of three integrated amplifiers, the A-0, A-1 and A-2, each carrying the ver.2 designation. The Soulnote A-2 ver.2 is an analog integrated amplifier rated at 80 watts per channel into 8 ohms and 160 watts per channel into 4 ohms.

The A-2 ver.2 uses a parallel push-pull output stage with TO-3P transistors matched by current gain. Its driver stage also uses TO-3P transistors, operating at a relatively high standing current. The amplifier retains a four-stage Darlington configuration and uses discrete amplification circuitry without global negative feedback.

A single multilayer circuit board accommodates the input connections, source selector, volume attenuation circuitry and voltage-amplification stage. Volume adjustment uses a balanced relay-switched resistor attenuator, while a 70-micrometer internal copper layer serves as a current-carrying bus. Several internal circuit-board connections use directly soldered wires.

A dedicated power-amplifier mode bypasses the source selector and volume control, while also interrupting power to the microcontroller. External preamplifiers can connect through RCA or XLR inputs, and the A-2 ver.2 supports mono and bi-amping configurations. The amplifier measures 430 × 162 × 423 mm and weighs approximately 20 kg.

The accompanying A-1 ver.2 uses a single push-pull TO-3P output stage, a new non-impregnated toroidal transformer and two XLR inputs. It is rated at 40 watts per channel into 8 ohms and 80 watts per channel into 4 ohms. The A-0 ver.2 delivers 10 watts per channel into 8 ohms, with a headphone output rated at 3 watts per channel into 32 ohms. That model provides RCA and XLR preamplifier outputs and allows selection of whether its speaker terminals remain active during preamplifier-output operation.