The Diana Forte’s circuits are based on the Diana Integrated amplifier output and driver stages. The Output stage is scaled up to deliver over twice the power achieving a true 60W (70W peak) of SET magic per channel. The parallel SET output stage is built around the 813 DHT big bottle tube.  This in turn drives an oversized core OPT constructed using special winding techniques to deliver wide bandwidth at full power.

The amplifier driver stage is the one of the most  linear tubes, the 814 DHT tube, loaded with a special quality double-C core bifilar winded inter-stage transformer. The Diana Forte’s amplifier is connected to its accompanying Diana Mezzo pre-amplifier via our proprietary AC link. As with the Diana Integrated and the Concero amplifiers, all stages are coupled with our special AC link method of coupling, delivering superior performance in the frequency extremes, transient response, and overload conditions.

The output stage PSU is a dual completely separate set of choke-filtered capacitor banks using our unique Super-capacitors.  The SuperCaps come from a selection of special purpose film capacitors with ESL and ESR parameters 100 times lower than any film or electrolytic capacitor.

The high energy-high speed capacitor banks deliver a superbly robust power rail for the parallel SET output stage.

The driver stage also uses choke filtered capacitor banks, with their own separate power transformer to avoid PSU cross-talking.

All tubes can be biased and monitored on the fly as well as can be matched using the Diana Forte as a stripped-down tube tester. 

All six filament PSUs are triple filtered, so that the all DHT power amplifier delivers the lowest noise floor of any SET power amplifier.

Specifications

Max Power: 60W SE Class A (70W peak)

Max Power bandwidth: 15Hz- 110Khz

Noise floor: 100db

Combined gain: X 20 (26db)

Dimensions: 570mmW X 590mmD X 350mmH

Weight: 110Kg unpacked

Tubes: 2X814, 4 X 813