Diana Tube Integrated Amplifier
We released our long awaited integrated amplifier, the Diana, in 2015. Since then it has won much critical acclaim giving unsurpassed sonic bliss in a single though hefty package.
Using borrowed techniques and circuits from our top of the line monoblocks like the Concero 65, and pre-amplifier stages like the Pondera Ref, we have come up with what we believe is the absolute and superlative design in the integrated amplifier world.
The Diana is a three stage, all Directly Heated Triode Single Ended amplifier. All stages are coupled using interstage transformers.
All three stages are designed as Direct Heated Single Ended amplifier stages. The first two stages are loaded with highest quality bifilar wound interstage transformers, no coupling capacitors are present in signal path.
Input tubes are a pair of high power DHT 814 tubes driving another 814 pair, which then drives a pair of 813 DHT output tubes.
The power supplies are fed by a 800VA and a 1000VA (1800VA total) transformers, controlled by a soft start circuit.
The four 814 and two 813 tubes all have their own separate choke filtered power supply units and all 6 filaments are powered by six triple filtered PSUs. This provides solid power reserves and perfect isolation between all stages.
The output stage power supply uses three huge film 'super capacitors' weighing 3 kilos each and having 100 times less ESL/ESR than any other electrolytic technology.
Biasing of the input, driver and output tubes is attained via special biasing circuits, and all stages can be fully adjusted and monitored while listening.
Attenuation method is discrete relay switched resistors and remote control. In testing we found this sonically superior over more traditional methods using a pot or a stepped resistor type attenuator pot.