I'm a happy owner of Sunfire Symphonic reference stack.
The preamp is actually driving two amps in biamp setup. The tube monos are connected to the high-pass output @80hz and above. The Sunfire amp drives bottom. The Symphonic Reference amp easily outperforms matched power Bryston 4B-ST for a fraction of its price and no heat whatsoever arround the amp. However it's not considered to be a digital amplifier. It has a logic circuit that switches the output stage onto the different classes of operation depending on the load.
The preamp is actually driving two amps in biamp setup. The tube monos are connected to the high-pass output @80hz and above. The Sunfire amp drives bottom. The Symphonic Reference amp easily outperforms matched power Bryston 4B-ST for a fraction of its price and no heat whatsoever arround the amp. However it's not considered to be a digital amplifier. It has a logic circuit that switches the output stage onto the different classes of operation depending on the load.