325 preamplifier

Philosophy

A preamplifier should only amplify or attenuate the music signal, not change it in any way. No distortion, no hum or noise, at the same time achieving the lowest cross talk and widest bandwidth. The soulution 325 preamplifier elegantly meets these demands.

Layout

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. 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 325’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 325 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.

Power supply

A switched mode power supply and audiophile DC-DC converters with linear regulator provide the required supply voltages for the 325 preamplifier. Induction of noise is omitted by physical separation from the analog audio boards and effective shielding. Switched mode power supplies provide supply voltages that are more stable and lower in noise than other power supply technologies.

Theater-Mode

The 325 may as well be integrated in an Audio/Video system. One input can be defined as surround input. Volume and balance settings of the 325 preamplifier will be ignored for the surround Input.