Pass Labs INT-25 Integrated Amplifier

Description

Pass Labs Fet Amplifiers

At Pass Labs, we build Fet amplifiers with excessive output stages, huge heat sinks, and massive power supplies. We use the highest quality components in simple linear topologies, assembled and tested with care and subtlety. Our products measure well, sound great, and are reliable. With over twenty years of ongoing innovation, our X and XA amplifiers remain at the forefront of high-end audio.

Introducing the INT-25 Integrated Amplifier

The INT-25 embodies all the excellence of Pass Labs, packaged in a smaller, more affordable stereo Class A amplifier. It takes advantage of lower power requirements to feature simpler single-ended circuitry and fewer parts in the signal path, eliminating degeneration in all stages.

Enhanced Simplicity and Efficiency

With simpler and fewer gain stages, the INT-25 achieves improved speed and stability. Lower voltages allow gain devices to run at higher bias currents, extending further into Class A operation. Newer power Fet technology replaces banks of parallel small transistors with a single pair of industrial devices, each rated at 700 watts / 40 amps. This results in no current-hogging issues and a new constant-current bias circuit that compensates for temperature drift, connecting directly to the loudspeaker without ballast resistors for the lowest possible distortion and highest damping factor.

Superior Circuitry

The INT-25’s front end circuit uses two pairs of our favorite NOS complementary Fets in common-source mode in a current feedback (CFA) configuration. The preamp section is a simplified single-ended version of the one used in the INT-60 and INT-250, featuring three line-level inputs and no line-level output.

Pure Listening Experience

Everything done in the signal chain from the microphone to the loudspeaker leaves an indelible mark on the music. The XA25 amplifier section is direct-coupled, requiring no DC servos or frequency compensation, ensuring that it neither adds to nor subtracts from the listening experience. As with all Pass amplifiers, the technology and construction of the INT-25 are strictly in the service of the listening experience.

Unmatched Sound Quality

The INT-25 measures superbly, but its subjective qualities are most special. In an industry where products with great specs are often found to be dry and boring, this amplifier breathes new life into the music, offering a vibrant and engaging listening experience.

KEY FEATURES:
• Class A Stereo Amplifier: Superior sound quality with a simpler single-ended circuitry for enhanced performance.
• Advanced Fet Technology: Uses industrial-grade power Fets for lowest distortion and highest damping factor.
• Direct-Coupled Design: Eliminates DC servos and frequency compensation for pure, uncolored audio reproduction.