PA-1175 MKII

The Gold Note PA-1175 MKII is a stereo power amplifier rated at 175W per channel into 8 ohm. It can also operate in mono through BTL, or Bridge-Tied-Load, with an output of 350W per channel.

Designed as Gold Note’s first stereo amplifier, the PA-1175 combines design knowledge developed for the Demidoff single-ended amplifiers with a higher power rating and new technologies. Each channel uses 4 matched pairs of transistors, equivalent to an 8-transistor-per-channel single-ended amplifier, with GN Design derived from the Diamond Line. A constant-current generator provides high current and high power with ultra-low distortion.

Gold Note’s Optical BIAS regulates the amplifier’s voltage reference. Optical decoupling analyses the audio signal while remaining separate from the audio signal path, avoiding the limitations of traditional electronic solutions. Optical Output Protection is designed to maintain audio performance.

BTL operation allows the amplifier to be used as a mono unit, increasing its power from 175W per channel at 8 ohm to 350W per channel. In this configuration, it provides the power, energy and output required by speakers that demand higher levels of amplifier power.

The power supply uses a custom 630VA toroidal transformer with a cut spiral nucleus. This mechanical design stabilises the nucleus and reduces mechanical vibration, while original Ducati silent blocks provide further isolation. A secondary 6VA transformer supplies the auxiliary functions through dedicated circuits outside the audio signal path.

An adjustable damping factor is selected from the front panel. The 250DF setting provides the power and control required by large, difficult speakers and other low-sensitivity loads. 25DF is intended for high-sensitivity and smaller speakers, including mini monitors, with the behaviour of a lower-power tube amplifier.

A solid steel chassis and thick aluminium panels are used to reduce potential RFI and EMI issues.