858 Dual-Mono Power Amplifier

  • 858
  • 855_back-screen-sm

With 20 years of design and production experience behind them, the new 858 Dual Mono Power Amplifier is the finest amplifier Lindemann has ever produced and showcases a refreshing new approach using the “single ended push-pull” circuit design. This concept originated from vacuum tube technology, but is now being employed for the first time ever in a fully-symmetrical transistor amplifier with current feedback. This means that the transistors used were configured to amplify the entire musical waveform with a natural and organic presentation.

Dual-Mono Configuration

The 858 is comprised of two complete and separate amplifiers housed together in a single chassis. The only connection between the left and right audio is at the power socket. Each channel is equipped with its own 800-watt transformer, resulting in superb channel separation, vivid stereo imaging and spatial reproduction.

Symmetrical Signal Processing

Both channels of the 858 are fully symmetrical. The high level of common mode rejection attained using this circuit principle allows for a higher dynamic scope than otherwise possible with asymmetrical circuits. This is an extremely important prerequisite for rendering higher resolution from  musical recordings!

“Current Mode” Amplifier

The amplifier circuit of the 858 is the real highlight. The fully symmetrical design, featuring current feedback, is based on an concept originating from valve amplification: the “single ended push-pull” amplifier. Using special and highly linear transistors from Japan allows this principle to be successfully applied to our “current mode” amplifier. Reducing the number of components required and implementing extremely short signal paths, paves the way for a huge increase in resolution. Meticulous selection of components, close-tolerance thin film resistors and low-loss film capacitors contribute to an unparalleled playback quality.

Intelligent Quiescent Current Adjustment

The 858 incorporates “thermal track” power transistors. These transistors feature a diode on the transistor chip that immediately senses the temperature and instantaneously adjusts the quiescent current to the correct level. This eliminates any quiescent current problems typically encountered by “class AB” power amplifiers.

Push-Pull Output Stage

Each channel of the output stage of the 858 is equipped with 16 high load-capacity power transistors. In contrast to standard amplifiers, these transistors are not housed next to each other, but in the form of an exceptionally low-induction H-bridges. This effectively prevents any losses due to eddy currents in the high-frequency range. The result is a exquisitely fine and transparent playback, even at low volumes.