Power amplifier A 32 of the Swedish company Primare.
Primart A32 40-kilogram block of gigantic dimensions (depth - more than half a meter!). The main burden falls on the front part, where a 2-kilowatt torus is installed. The circuit also has a smaller transformer for powering digital circuits - the RS232 interface and the protection / heating system. The latter is required for correct start-up of the power source, in particular, smooth charging of capacitors with a capacity of 90,000 μF in each channel. Without it, when the amplifier is turned on, the surge of current can be such that it knocks out the machines on the apartment switchboard. In addition, for reliability, secondary voltage stabilizers are started in a strictly defined sequence. The protection is activated in case of overheating, the appearance of a constant voltage at the output or a short circuit in the load circuit. Two Standby modes are provided - audiophile, when power is supplied to all stages of the amplifier, but the acoustics are turned off using a relay. In this case, it will not have to be warmed up before listening, which, as it turned out later, is vital. The second Standby is economical, in it this monster with a capacity of 2 x 400 W (4 Ohms) consumes less than 2 W from the network.
The circuit of the amplifier is completely symmetrical, the transition from balanced XLR inputs to conventional RCA is carried out using a toggle switch on the rear panel. For better decoupling from the power supply, the rectifier is built on two diode bridges with a floating "ground".
To put the amplifier into working mode, in addition to the key on the back, you need to press the central part of the logo engraved on the front panel.

Specifications

Output power, W
– on a load of 8 Ohms 2 x 250
-on a load of 4 Ohms 2 x 400
Reproducible frequency range (-0.5 dB), Hz 20 – 100000
Gain, dB
- balance input 20
– input RCA 26
Distortion factor (250 W, 1 kHz, at a load of 8 ohms)%