“We proudly announce the completion of the Diana Series of amplification with the introduction of two new models.  Following on from our Diana integrated amplifier, the Diana Forte – arguably the most powerful Single Ended Triode (SET) stereo amplifier in the World and the Diana Mezzo, its accompanying Class A Pre-amplifier.

The two models share the majority of circuits with the Diana integrated and technically, is a two chassis improved version of the integrated. Customers have the benefit of purchasing the Diana Mezzo Pre-amplifier and later getting Diana Forte for a perfect match.”

Stavros Danos
DESIGNER: ARIES CERAT

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 output transformer constructed using special winding techniques to deliver wide bandwidth at full power.

The amplifier driver stage uses one of the most linear tubes – the 814 directly heated triode tube, loaded with a special quality double c-core bifilar wound interstage transformer. The Diana Forte’s amplifier is connected to it’s accompanying Diana Mezzo pre-amplifier via our proprietary AC link. As with the Diana integrated and the Concerto 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 power supply unit is a dual completely separate set of choke filtered capacitor banks using our unique super capacitors. The super capacitors come from a selection of special purpose film capacitors with ESL and ESR parameters 100 times lower than any film or electrolytic capacitor currently in use today.

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 matched using the Diana Forte as a stripped down tube tester.  All six filament PSUs are triple filtered, ensuring this all DHT power amplifier delivers the lowest noise floor of any SET power amplifier.

SPECIFICATIONS
Tubes: 2 x 814, 4 x 813
Maximum Power: 60W SE Class A (70W peak)
Maximum Power bandwidth: 15Hz- 110Khz
Noise floor: 100db
Combined gain: x 20 (26db)
Dimensions: 570mm W X 590mm D X 350mm H
Weight: 110Kg unpacked