520 preamplifier

Unbalanced design ensures the fewest components in the signal path. Physical separation of the left and right channel provides optimal separation and cross talk performance. High quality relays switch between the inputs. Source signals are buffered directly at the input. For safety, an audio grade coupling capacitor protects the preamplifier as well as downstream amplifiers and loudspeakers from potential DC components in source signals.
Volume control
The 520’s volume control uses only high-precision, low-noise metal foil resistors, and it controls both the volume and balance. To block switching peaks during volume changes which may be hazardous to power amplifiers, the 520 is equipped with a second volume control with a PGA (Programmable Gain Amplifier). Active only during the volume control process, it is similar to a potentiometer and enables the volume to be adjusted in smooth, click-free steps. As soon as the new desired level value has been selected, the unit returns control to the precision resistors.
Output stage
Multi-stage, similar to that used in the reference 720 preamplifier, it achieves very fast, ultra wideband (1MHz/-3dB) amplification and is able to drive the longest interconnects with ease.
Similar to the 720, the phono preamplifier of the 520 is also multi-stage using the highest grade components.
The 520 is operated via its front-panel buttons and rotary control. Multi-functional, these allow optimisation of the entire audio system, and an ideal set-up of the individual components.
Analogue Inputs:
- 2x balanced input (XLR)
- 2 x unbalanced input (RCA)
- 1x phono
Analogue Outputs:
- 1 x balanced (XLR)
- 1 x unbalanced (RCA)



Nominal voltage
Model 220 – 240 V / 50 – 60 Hz: 220 – 240 V
Model 100 – 120 V / 50 - 60 Hz: 100 – 120 V

OFF (standby): <0.5 W
Operation: 100 W

Input (IN 1 ... IN 5)


balanced (IN 1... IN2): 3 kΩ
unbalanced (IN 3...IN4): 3 kΩ
Phono (IN 5): adjustable



balanced: -83...+16 dB
unbalanced: -89...+10 dB

Frequency response: DC-800 kHz

THD+N: <0.001 %

Signal-to-Noise Ratio: >120 dB

Crosstalk: <120 dB


balanced 10 Ω
unbalanced 10 Ω

LINK-System: +12 V