RAAL-Requisite has released the HSA-1b amplifier. The novelty is intended primarily for the RAAL-Requisite SR1a ribbon headphones, which we have already talked about – the HSA-1b can work with them without step-up transformers. For this, the amplifier circuitry provides for the ability to work with an impedance of up to 0.3 Ohm.
At the same time, the HSA-1b can be used with ordinary headphones: for this it is equipped with XLR4 connectors and a 6.3mm jack. These jacks are located on the front panel, next to a large volume encoder that controls a stepped resistance set switch.
The rear panel of the HSA-1b has two line inputs (balanced and unbalanced) and speaker cable terminals. The amplifier is ready to deliver 10 watts per channel to 8 ohm speakers. If this resistance is reduced to 1 Ohm, the power will increase to 50W.
The cost of the HSA-1b in the US was $4,500. Optionally, the amplifier can be supplemented with a carrying case for $350. A set of SR1a headphones and HSA-1b amplifier in a plastic case will cost $8,000.