NEW AUDIO FRONTIERS LEGEND MKII

Pre owned. In good condition. It has minor signs of wear on the side panels, also visible in the photos. Supplied with remote control and manual, not supplied with the original packaging.

Tube-based stereo integrated amplifier developed around the KT66, a beam tetrode already used in renowned designs by Quad, Leak and Radford. The design differs from the configurations traditionally adopted for this tube and uses it as a triode in a Push-Pull configuration, operating in pure Class A and without negative feedback.

The output stage uses a pair of KT66 tubes per channel, triode-connected and configured in Push-Pull, delivering an output power of 18 W per channel. The design is intended to drive loudspeakers with a sensitivity of 93 dB/W/m or higher. The circuit adopts a dual-mono configuration, keeping the sections serving the two channels separate.

The power supply also follows a design focused on separating the different sections. The anode voltage is obtained through a pi filter, used to improve smoothing and filtering of residual noise. The tube filaments are supplied with stabilized DC voltage, with the exception of the four KT66 output tubes.

The driver stage uses a 6922 tube as the first signal amplification stage, followed, for each channel, by a pair of 5687WA tubes configured as a differential amplifier. This solution is designed to achieve high circuit linearity and maintain transparency in signal reproduction.

The circuit also uses an automatic tube biasing system, which maintains the correct operating point without the need for manual adjustments. The absence of negative feedback is part of the design approach adopted by New Audio Frontiers for the pure Class A operation of the output stage.

The output transformers are hand-wound by New Audio Frontiers using Litz copper conductors. The core is made from 0.1 mm-thick M0 laminations, while the double-wire winding is designed to limit parasitic oscillations and losses in the core. This section completes the circuit design of the Legend MKII, characterized by the use of KT66 tubes, Class A Push-Pull operation and a dual-mono configuration with separate sections.

In reproduction, the Legend MKII combines a three-dimensional stereo soundstage with a fast dynamic response. Its tonal balance maintains a degree of smoothness together with a transparent mid-to-high frequency range, with particular attention to the reproduction of both male and female voices. The circuit design and tube selection are therefore aimed at achieving articulate, dynamic and transparent reproduction.

Technical specifications:

• Type: tube stereo integrated amplifier
• Continuous power per channel: 18 W into 8 ohms
• Total harmonic distortion: 5%
• Inputs: 5 RCA line inputs
• Input sensitivity: 800 mV
• Input impedance: 100 kOhms
• Output tubes: 4 x KT66, triode-connected in Push-Pull configuration
• Driver tubes: 1 x 6922; 2 x 5687WA
• Operating class: Class A
• Configuration: Push-Pull; dual-mono
• Biasing: automatic
• Output transformers: hand-wound with Litz copper conductors and 0.1 mm M0 laminated cores
• Dimensions (W x H x D): 310 x 240 x 480 mm
• Weight: 40 kg