Bel Canto Looks Good in Black
Bel Canto's John Stronczer was excited. "The Powerstream amplifier's S/N ratio is 120dB measured at the speaker terminals!" I was impressed. This is equivalent to 20-bit digital audio, which means this digital-input monoblock, which costs $15,000 each, is one of the quietest amplifiers I have encountered. It offers 300W into 8 ohms, 1200W into 2 ohms. Audio data presented to the ST-optical inputs are reclocked and then converted to analog with a BurrBrown PCM1792. The analog signal is then fed to an output stage based on the well-regarded Hypex class-D modules, used in a proprietary low-gain configuration to maximize dynamic range.
The complementary Stream Controller ($20,000) shown at the top of the detail photo accepts digital data in all the usual formatsUSB, AES/EBU, Toslink, uPnP-compatible Ethernetsampled at up to 384kHz and reclocks them to minimize jitter. A 64-bit DSP engine is used for the volume control and there are two ST-optical outputs and one AES/EBU output. Both the Stream Controller and the Powerstream are housed in black-anodized chassis machined from solid aluminum with constrained-layer damping applied to the baseplates to minimize resonances.
In a system featuring TAD CR1 speakers, Kimber Select cables, and HRS racks, the sound in this room with the familiar Reference Recordings Rite of Spring (24-bit, 176kHz WAV file on an HRX disc) was superb, and the best I have experienced from the TADs.