"HP300 SE is Octave’s new generation preamplifier, an enhanced version of the previous HP300 MK2 with improvements on the power supply and output sections; gain adjustment has also been increased to 3 levels from the previous 2 which makes power amplifier matching more flexible. HP300 SE has a separate power supply. Most might think that the power supply on a preamplifier would not be very large so why should it be separated from the main unit? Octave has been paying a lot of attention on power supply design which includes power source, its treatment and the amplification part. The reason for a standalone power supply is to isolate the transformer’s magnetic flux from the main unit…"