Original valve, digital recall, programmable distortion unit. Gets the best of both worlds. Analog drive tone, but digital presets / recall / control (complete with MIDI).

Been happily sitting in my rack for a number of years.

Super reliable, super versatile, awesome sounding bit of kit.

Collection from Central London (WC1) or courier (£20).

From theTech 21 website:

Discover the Tech 21 SansAmp PSA-1.1, a legendary rackmount preamp and amp emulator that’s earned its place in studios and on stages worldwide. Designed for guitarists, bassists, producers, and session players, this powerhouse combines an all-analog signal path with digital preset recall, giving you the warmth and feel of classic tube amps with modern programmability and flexibility.

At its core, the PSA-1.1 offers 49 iconic factory presets capturing the character of vintage and contemporary tube amplifiers, plus 77 user-definable slots so you can store your personal tones for rehearsal, recording, and performance. Real-time analog potentiometers give tactile control over your sound, while MIDI compatibility lets you integrate seamlessly with controllers and software rigs.

Connectivity is versatile: dual 1/4″ inputs accommodate different sources, and both 1/4″ and XLR outputs with switchable levels let you send pro-level signals to PA systems, recording interfaces, or guitar/bass amps. An effects loop expands your sound shaping possibilities, and optional headphone outputs make tracking and practice easy.

The intuitive front-panel layout features Pre-amp, Buzz, Punch, Crunch, Drive, and EQ controls, giving you deep-dive tone sculpting without complexity. Whether you’re tightening low end, dialing classic crunch, or blending aggressive drive, the PSA-1.1 responds musically and dynamically.

Built ruggedly in a 1U rack format with a shielded steel/aluminum chassis, the SansAmp PSA-1.1 thrives in touring racks and studio racks alike. If you want authentic tube-style tone, flexible routing, and hands-on control all in one unit, the PSA-1.1 is a professional-grade tool that elevates any rig.

Full Specifications (Tech 21 SansAmp PSA-1.1)

General

• Rackmount preamp/amp emulator with 100% analog signal path and digital preset recall.
• 49 factory presets capturing classic and modern tube amp tones for guitar and bass.
• 77 user-definable program locations.
• Universal output section for compatibility with full-range systems and traditional guitar/bass amps.
• MIDI control for remote preset changes.

Inputs & Outputs

• 2 x 1/4″ inputs (Input 1 @ 1 MΩ, Input 2 @ 4.7 MΩ).
• XLR and 1/4″ outputs with switchable levels (line/instrument).
• Effects loop send/return.
• MIDI In/Thru for integration with controllers/software.
• Headphone output on some configurations.

Tone & Controls

• Pre-amp, Buzz, Punch, Crunch, Drive, Low, High, Level, Trim controls for sculpting tone.
• Afterburner low-cut/hi-boost option on some versions.

Physical

• Rackmount 1U size: ~19″ x 1.75″ x 5″ (6″ with connectors).
• Weight ~5 lbs.
• Robust aluminum and steel chassis.