The predriver and driver gain stages are self biased, while the output stage is active bias which is adjusted by control pots on the front of the amplifier. Active bias eliminates any regenerative feedback at the critical output stage thus optimizing the dynamics of the amplifier. The predriver and driver stage use self bias to maximize linearity of these critical gain stages. No other negative feedback is used, nor needed. The 572 directly heated triodes use AC filament voltage.

Additional Circuit Features
Separate pi filters for the predriver/driver stage and the output stage isolate each other using capacitors and customized toroidal chokes. RC networking further isolates the predriver, cathodyne and driver stages.

There is one circuit board in the power supply, which contains the soft start circuit and AC power management/filtering.

All amplifier circuit wiring is point to point and utilizes high quality turret wiring posts.
Custom constructed, highly polished copper signal runs are used wherever practical. All power supply and filament runs are shielded to reduce crosstalk and EMF noise.

Description of Soft Start
The AC power is conditioned and filtered from line voltages.
The soft start circuit is used to increase the life of the tubes. This is accomplished by stepping up the filament and bias supply voltage, allowing the tubes to come to operating temperature before high voltage is applied to prevent thermal shock. Specifically, the filament and bias supply are stepped up (approximately 30 seconds), then after a two-minute delay for thermal stability high voltage is applied to the vacuum tubes.

Case Characteristics
The elegant upright case serves more than visual appeal. It was designed for both electrical and temperature considerations. This arrangement allows separation of AC line voltage and power supply EMF from the audio circuit while also minimizing circuit-wiring paths.
The tower case also enhances convection cooling thus eliminating the need for fan cooling. This again enhances the life of components.

The substantial chassis is made from 1/8”, 3/16”, and 3/8” aluminum, which ensures a stable mechanical and electromagnetic environment for enhanced sonics.

Another feature of the case design is decorative front wings, which allows the customer to customize the look to compliment his or her home décor.