All the flavor with no calories! If heat is measured in calories, Superpower uses very few calories compared to a shunt regulator. The shunt we measured looks like the one here: http://www.tnt-audio.com/jpg/ph_21.5_reg.jpg. Components are on the bottom and the top is mostly 2 heat sinks. This model has a maximum output current of about 220mA as you can see below.

Beyond the size and heat issues, shunt regulators also need several volts of overhead at Vin, known as drop out. This one is no exception, with a drop out of 4V to 5V.

Ripple Rejection

Superpower's extreme output isolation again delivers better ripple rejection than any other regulator, even a shunt. This graph shows the level of AC output voltage compared to an input sine wave superposed onto the DC value of Vin, so the lower the value the better the performance. The shunt regulator has rejection (PSRR) in the -100dB range across the audio band, and also had 2nd and 3rd harmonics that are not shown here that are in the main audio band. Superpower has -115dB at very low frequencies such as those of a mains power supply. This gives about a factor of 6 advantage to Superpower!

Dynamic performance

The Paul Hynes has lower noise than the Superpower, as you can see in the photos below. Keep in mind however, power supply noise is a secondary consideration in amplification systems—it's well known that the primary contributor to noise is the amplifier input noise and not the supply noise.

The measurements were made by pulsing a power transistor to sink 200mA from a Hynes and from a SPJ78 Superpower. Both regulators have Vout=15V.