Thalia

About the Thalia

The Thalia is a servo-loop stereo preamplifier designed by Great American Sound (GAS) in 1977–78. It features a fully complementary symmetry design, multiple line inputs, a tape loop, and dual phono inputs with a high-quality moving magnet (MM) phono stage. The volume, bass, and treble controls use precision discrete resistors rather than potentiometers, offering repeatable settings and long-term reliability. The tone controls are located in the feedback loop for minimal phase shift, and a four-position low-frequency filter allows for tailored bass response. The preamp is DC-coupled after input isolation capacitors and uses servo-amplifiers outside the audio path to maintain zero DC interstage voltages. It is designed to pair seamlessly with GAS power amplifiers and is regarded for its sonic performance and build quality.