Pathos Synapse Reference Stereo Preamplifier

This new balanced preamplifier represents the state-of-the-art of Pathos technology and is a worthy partner of the Adrenaline power amp.

The bottom half of the two-chassis design contains a power supply and all control and display circuitry, and the top half contains the analog signal stages, kept far away from electrically noisy parts. Each section has its own ground. The connection between the two stages is via photo-couplers for complete separation and to avoid ground loops.

Signal management is assigned to a hybrid which uses a double triode 6H30 and then two buffer stages. The first is a tube with the second double triode 6H30, and the second uses a MOSFET tracker offering maximum linearity. This is a true balanced design as evidenced by the two volume regulators per channel.

Other details are the engagement of only the inputs in use, a memory for volume levels, and a three-step gain setting (0 dB, +6 dB, +12 dB).

The power supply is so complex, it almost looks like a power amplifier. Multiple power supplies handle the line stages, anodic voltage, voltage filaments (one per each tube), and analog volume-control stages. A separate section handles the supply to the digital circuits. 

Specifications

Inputs: Balanced XLR x 3, RCA x 3

Outputs: Balanced XLR x 2

Output Impedance: 33  Ω

Frequency response: 1 Hz - 100 kHz (200 kHz at -3 dB)

THD: 0.04% at 4 VRMS

Volume control: 0.5 dB, 168 steps

Tube complement: 6H30 x 4

Dimensions (WHD): 16.9" x 10.2" x 20.8"

Weight: 50 lb