Technical Data

The power supply includes a large capacity toroidal power transformer (pictured at
bottom center in the photo above), which carries a raw power capacity rating of 2.8 kVA.
For the №53, the power transformer is conservatively de-rated to a more reasonable
1.065 kVA, to ensure long term operational stability and lower thermal operational limits
to conform to electrical safety compliance requirements.
In addition to 188,000µF of local capacitance in the main power supply section, the
№53 power amplifier boards feature an additional 105,600µF of local capacitance, for a
total of 293,600µF capacitance (146,800µF per voltage rail), for a combined storage
capacity of approximately 680 Joules.
With the high power output amplifier sections, combined with the main and local power
supply capacities, the №53 is capable of tremendous power output. Rated at 500 watts
continuous into 8 ohm loads and 1,000 watts continuous into 4 ohm loads, the
tremendous headroom of the №53 allows for substantial short term power output bursts,
including peak (dynamic power) bursts of up to 2,000 watts into very low 2 ohm loads.
The amplifier’s output impedance is also quite low, which provides for very high
damping factor (~8,800 at 20 Hz and ~5,500 at 40 Hz). This high damping factor lets the
driving loudspeaker “see” a virtual short circuit path back to the amplifier, limiting the
effects of back EMF (Electro Motive Force), which provides for the tightest deep bass
response with full range audiophile loudspeakers.
The №53 also boasts greatly increased thermal efficiency, compared to conventional
Class AB designs. As much less of the power going through the output devices is
converted to heat, the amplifier runs cooler, and in fact needs no forced air cooling,
which is almost always the case with high power Class AB designs. Arrayed along the
№53’s chassis sides are four massive heat sinks directly coupled to the vertical
MOSFET power output devices, and they collectively provide over 14.5 square feet of
radiating surface area. Even after extended high volume listening at elevated power
output levels, the heat sinks are merely warm to the touch, allowing side-by-side
configuration in multiple amp rack setups and greater installation flexibility.
Operational Stability
With conventional Class AB designs, reactive loudspeaker loads can result in shifts in
phase between output current and voltage, which can necessitate the amplifier’s
protection circuitry kicking in at lower than ordinary levels to limit output current. The
№53 is not bound by this constraint, as it will only limit current without caring about
voltage, regardless of phase.
The current output capability of the №53 is indeed prodigious. For example, 500 watts
into an 8 ohm load equates to a current flow of just under 8 amps. At 1,000 watts into 4
ohms, the figure doubles to just under 16 amps. Due to the tremendous power reserves
and the robustness of the output stages, the №53 is capable of delivering short burst
current peaks of around 70 amps, and around 50 amps peak over time. This ensures