CODA 33.0

The 33.0 normally operates in stereo mode, providing a maximum output power of 330 watts Class AB (into an 8-ohm load) per channel. In bridged mode, both channels act as one amplifier providing a maximum output power of 660 watts. For extremely high-power multi-channel audio applications, multiple 33 amplifiers can be used in place of one stereo amplifier.

Extremely wide bandwidth transistors are used in the output stage instead of the usual. To maintain “Precision Bias” requires an advanced bias circuit that must have a very high degree of stability under a wide range of temperatures and load conditions.

Most amplifier bias networks are of such high impedance and poor thermal regulation that at the extremes of operation, bias currents are ineffectively controlled. Advanced tracking techniques used in the 33.0 result in absolute control of bias currents under all conditions.

The main power supply of the amplifier consists of two 2000VA toroidal power transformers (or one 3000VA transformer in the EU) with independent rectifiers to isolate the channels from one another. 184,000 microfarads of total capacitance provide effective filtering of all AC ripple.

These attributes result in a amplifier of such extreme linearity and bandwidth that no overall feedback correction is required or used. One advantage of this is a high degree of immunity from interactions with loads or cables and a superior transient response. An extremely low nonreactive output impedance is maintained well beyond 20,000 hz. The resulting uniform damping factor is not commonly found in other designs.

The chassis of the 33.0 is constructed of machined aluminum milled to very close tolerances yielding the seamless appearance characteristic of previous products from Coda. As with all high-power amplifiers, heat dissipation is important. The 33.0 uses six massive aluminum heat sinks without fans for efficient, noiseless, and clean thermal relief. The thermal coefficient of the 33.0 heat sinks is one of the lowest and most effective in the audio industry.

TO3 devices used in other output designs. Each channel uses 30 individual output transistors with a combined power rating of 1500 Watts and 120 Amperes with a bandwidth of 50 Mhz.

The 33.0 uses bias voltages and component values which have been specifically selected to produce a precision transition with no abrupt changes in distortion or output impedance. This “Precision Bias” technique yields seemless performance regardless of the complexity of the load impedance and is particularly effective at eliminating IM distortion which often occurs in these instances.