326 Preamplifier

Description

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. For safety, an audio grade coupling capacitor protects the preamplifier as well as downstream amplifiers and loudspeakers from potential DC-components in source signals.

Preamplifier and volume control
Relay-switched high precision metal foil resistors form an 80 step (1 dB) volume control. To avoid unpleasant clicking noises or harmful voltage peaks during volume adjustments, the 326 is provided with a second volume control path which is active only during volume adjustments. This secondary, IC based volume control alters the volume without any click or pops. Once the new volume is set, the 326 will revert to the sonically superior path with its high-precision metal foil resistors. The frequency bandwidth of the preamplifier section could be extended to more than 2MHz (-3dB), which does significantly reduce the phase shift in the audio band.

Phono stage (optional)
A two stage, active/passive, design equalizes the input signal according to the RIAA specifications. Tight tolerance, high quality passive components in the RIAA networks ensure highest precision of the required time-constants. Three wide bandwidth, low noise amplifier stages provide 60dB gain with minimal deviations to the ideal frequency and phase response of the system. The adjustable termination impedance (via the remote or front panel controls) allows to perfectly align the phono stage to your MC phono cartridge.

DAC (optional)
With its 4 digital inputs (SPDIF, AES/EBU, Network, USB) provides connectivity to a wide selection of digital sources. A powerful DSP converts all incoming digital music signals to the DXD format, performs the zeroPhase processing and the LEEDH volume control. One PCM1792 in mono configuration per channel takes care of the digital to analogue conversion of the music signals. The internal digital filtering of the chip is bypassed for optimal results. The passive reconstruction filter sports custom made high precision components ensuring stable filter characteristics, prerequisite for a perfect compensation with the zeroPhase technology.

Operation
The 326 preamplifier is operated via its three front panel buttons and rotary control. Multiple configuration functions allow optimisation of the entire audio system, and an ideal set-up of the individual components. All operating modes are indicated on the clear display.