AGI Model 511 Vintage High-Speed Stereo Preamplifier MM Phono Stage (1978)
Rediscover exceptional vintage hi-fi performance with the AGI Model 511, a highly regarded stereo preamplifier designed by David Spiegel of Audio General, Inc. Introduced in the late 1970s, this audiophile preamp is celebrated for its ultra-fast circuitry, exceptionally low distortion, and high-quality moving-magnet phono stage. Featuring multiple analog inputs, dual tape monitoring, dubbing controls, and dedicated equalizer connections, it offers excellent flexibility for a vintage stereo system. Fully tested, refurbished, and SPENCERTIFIED for reliable everyday listening.
CONDITION
SPENCERTIFIED- Fully certified by Spencer
Refurbished and SPENCERTIFIED
100% tested and functional. Controls and switches cleaned with WD-40 Specialist Electrical Contact Cleaner. Internal boards and connections inspected, RCA inputs and outputs checked, phono preamplifier operation tested, and both stereo channels verified for proper audio performance. Tape monitoring, dubbing functions, balance control, and input selection checked for proper operation.
Cosmetic Condition: 9/10.
Functional Condition: 10/10.
WHAT'S IN THE BOX?
- AGI Model 511 Stereo Preamplifier
FEATURES
- Vintage High-End Stereo Preamplifier
- Designed by David Spiegel
- High-Speed, Low-Distortion Solid-State Circuitry
- Premium Moving Magnet (MM) Phono Preamplifier
- RIAA-Equalized Phono Input for Turntables
- Adjustable Phono Cartridge Loading Capability via Internal Plug-In Capacitor Arrangement
- Ultra-Fast Phono Circuit Slew Rate Exceeding 250V/µs
- Wide-Bandwidth Circuit Design
- Low-Noise Audio Reproduction
- Phono, Tuner, and Auxiliary Input Selection
- Dual Tape Deck Inputs
- Dual Tape Recording Outputs
- Tape 1 and Tape 2 Monitoring
- Tape Dubbing Capability
- External Equalizer Input and Output Loop
- Tone Send Function for External Signal Processing
- Mono/Stereo Switching
- Independent Volume and Balance Controls
- Low Output Impedance for Power Amplifier Compatibility
- Gold-Plated Internal Component Sockets
- High-Quality Internal Components
- Front-Panel Power Indicator
- Rear-Panel AC Convenience Outlets
- Classic Vintage Audiophile Design
- Designed for Use with an External Stereo Power Amplifier
SPECIFICATIONS
- Channels: 2-Channel Stereo
- Amplifier Type: Solid-State
- Phono Compatibility: Moving Magnet (MM)
- Phono Gain: 33dB ±0.25dB at 1kHz
- Line-Level Gain: 18.7dB ±0.25dB
- Frequency Response: 20Hz–20kHz ±0.1dB
- Total Harmonic Distortion: 0.005% or Less
- Phono Signal-to-Noise Ratio: 88dB or Greater
- Phono Input Impedance: 47kΩ / 90pF
- Line Input Impedance: 38kΩ
- Line Output Impedance: 47Ω
- Maximum Line Output: 9.5V into 10kΩ
- Phono Slew Rate: Greater Than 250V/µs
- Line Stage Slew Rate: Greater Than 50V/µs
- Power Consumption: Approximately 5W
DIMENSIONS
- 13.9" x 9.6" x 5.2" (Length x Width x Height)
- Weight: 13.2 lbs
INPUTS
- Tape L/R x2 (back)
- Equalizer L/R x1 (back)
- Phono L/R x1 (back)
- GND x 1 (back)
- Tuner L/R x1 (back)
- Aux L/R x1 (back)
OUTPUTS
- Tape L/R x2 (back)
- Equalizer L/R x1 (back)
- Main Output L/R x1 (back)
- AC Outlets x 6 (back)
MANUFACTURER
- MFD. 1978
- Made in USA
