501 mono amplifier



The amplification circuit of the 501 is based on the technology of the 710 and 700 amplifiers. At its core is a proprietary voltage amplification stage that consists of linearized amplifiers operating up to a cutoff frequency of 80MHz.
Current amplification is done in three stages, each using a very small and thus almost linear operating range. The high Class A operation supplemented by 47,000µF of storage capacitance results in a nearly infinite impulse response. Massive copper bars on the amplifier board and to the speaker terminals ensure that all the power of the 501 mono amplifier is available to drive the speaker.
High-precision idle current management ensures optimal Class A operation for all conditions, without requiring any readjustment in the music signal. Optimal sound is thereby guaranteed immediately from switch on. Control circuits that protect against RF or DC signals at the input, and short circuits at the output ensure safe operation in all situations. The input level is also monitored continuously


A total of six power supplies - optimized for each function - feed the 501 mono amplifier. Those supplying the digital and audio circuits are electrically isolated from each other by optocouplers and transformers. Two cutting-edge switched-mode power supplies deliver 1,200W of audiophile quality power. They feature high performance filtering at the input and output, and six high speed soulution voltage regulators to deliver considerably more stable power than any conventional, transformer-based technology.
The 501 mono amplifier is operated via a rotary control on the front panel. It can be switched on remotely with other soulution devices via the LINK system


Analogue inputs:
- 1 x balanced input (XLR)
Analogue outputs:
- 1 x balanced output (XLR)
- 1 pair speaker binding posts





1 ×125 W @ 8 Ω
1 × 250 W @ 4 Ω
1 × 500 W @ 2 Ω

Standby: <0.5 W

Idle consumption: 100 W

Output voltage max.: 70 Vrms

Output current max: 45 A

Impuls rating: ~5'000 W

Sensitivity: 1.55 Vrms

Voltage amplfication: +26 dB

Frequency response: DC-800 kHz

Slew rate: 900 ns

Distortion (THD+N): <0.001 %

Signal-to-noise ratio: >120 dB

Damping factor: > 10'000

Input impedance: 2 kΩ

Output impedance: 0.001 Ω