Aurorasound HFSA-01 is stereo-integrated amplifier with a hybrid configuration that takes advantage of tubes and semiconductors. It has an output power of 14W+14W with EL84 tubes and bass and treble controls. The input section has a built-in phono equalizer, supports its MM cartridges, and has unbalanced 3-channel RCA input connectors.
The EL84 output tube is a pentode equivalent of the 6BQ5 and features push-pull operation and an ultra-linear connection with excellent distortion and frequency characteristics. To drive the EL84, a phase-inverting circuit using his Texas Instruments OPA604A is employed, as a high-precision standard audio operational amplifier, and a unique circuit was developed that provides an ideal drive.
The phono equalizer section is compatible with the usual MM cartridges and consists of an LF circuit with excellent SN characteristics, using a Linear Technology semiconductor.
In the power supply section, the tube circuit and the semiconductor circuit are independently separated so that there is no mutual interference at any volume or frequency. Rohm’s silicon carbide with the lowest noise is used for the rectifier diode.
The output transformer and power transformer are made in Japan and are custom-made for Aurora Sound.
