{"product_id":"agi-model-511-vintage-high-speed-stereo-preamplifier-mm-phono-stage-1978","title":"AGI Model 511 Vintage High-Speed Stereo Preamplifier MM Phono Stage (1978)","description":"\u003cp\u003eRediscover 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.\u003c\/p\u003e\n\u003ch3\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cb\u003eCONDITION\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cb\u003eSPENCERTIFIED\u003c\/b\u003e\u003cspan style=\"font-weight: 400;\"\u003e- Fully certified by Spencer\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-weight: 400;\"\u003eRefurbished and \u003c\/span\u003e\u003cb\u003eSPENCERTIFIED\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003e100% 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.\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-weight: 400;\"\u003eCosmetic Condition: 9\/10.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-weight: 400;\"\u003eFunctional Condition: 10\/10.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eWHAT'S IN THE BOX?\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eAGI Model 511 Stereo Preamplifier\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eFEATURES\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVintage High-End Stereo Preamplifier\u003c\/li\u003e\n\u003cli\u003eDesigned by David Spiegel\u003c\/li\u003e\n\u003cli\u003eHigh-Speed, Low-Distortion Solid-State Circuitry\u003c\/li\u003e\n\u003cli\u003ePremium Moving Magnet (MM) Phono Preamplifier\u003c\/li\u003e\n\u003cli\u003eRIAA-Equalized Phono Input for Turntables\u003c\/li\u003e\n\u003cli\u003eAdjustable Phono Cartridge Loading Capability via Internal Plug-In Capacitor Arrangement\u003c\/li\u003e\n\u003cli\u003eUltra-Fast Phono Circuit Slew Rate Exceeding 250V\/µs\u003c\/li\u003e\n\u003cli\u003eWide-Bandwidth Circuit Design\u003c\/li\u003e\n\u003cli\u003eLow-Noise Audio Reproduction\u003c\/li\u003e\n\u003cli\u003ePhono, Tuner, and Auxiliary Input Selection\u003c\/li\u003e\n\u003cli\u003eDual Tape Deck Inputs\u003c\/li\u003e\n\u003cli\u003eDual Tape Recording Outputs\u003c\/li\u003e\n\u003cli\u003eTape 1 and Tape 2 Monitoring\u003c\/li\u003e\n\u003cli\u003eTape Dubbing Capability\u003c\/li\u003e\n\u003cli\u003eExternal Equalizer Input and Output Loop\u003c\/li\u003e\n\u003cli\u003eTone Send Function for External Signal Processing\u003c\/li\u003e\n\u003cli\u003eMono\/Stereo Switching\u003c\/li\u003e\n\u003cli\u003eIndependent Volume and Balance Controls\u003c\/li\u003e\n\u003cli\u003eLow Output Impedance for Power Amplifier Compatibility\u003c\/li\u003e\n\u003cli\u003eGold-Plated Internal Component Sockets\u003c\/li\u003e\n\u003cli\u003eHigh-Quality Internal Components\u003c\/li\u003e\n\u003cli\u003eFront-Panel Power Indicator\u003c\/li\u003e\n\u003cli\u003eRear-Panel AC Convenience Outlets\u003c\/li\u003e\n\u003cli\u003eClassic Vintage Audiophile Design\u003c\/li\u003e\n\u003cli\u003eDesigned for Use with an External Stereo Power Amplifier\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eSPECIFICATIONS\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eChannels: 2-Channel Stereo\u003c\/li\u003e\n\u003cli\u003eAmplifier Type: Solid-State\u003c\/li\u003e\n\u003cli\u003ePhono Compatibility: Moving Magnet (MM)\u003c\/li\u003e\n\u003cli\u003ePhono Gain: 33dB ±0.25dB at 1kHz\u003c\/li\u003e\n\u003cli\u003eLine-Level Gain: 18.7dB ±0.25dB\u003c\/li\u003e\n\u003cli\u003eFrequency Response: 20Hz–20kHz ±0.1dB\u003c\/li\u003e\n\u003cli\u003eTotal Harmonic Distortion: 0.005% or Less\u003c\/li\u003e\n\u003cli\u003ePhono Signal-to-Noise Ratio: 88dB or Greater\u003c\/li\u003e\n\u003cli\u003ePhono Input Impedance: 47kΩ \/ 90pF\u003c\/li\u003e\n\u003cli\u003eLine Input Impedance: 38kΩ\u003c\/li\u003e\n\u003cli\u003eLine Output Impedance: 47Ω\u003c\/li\u003e\n\u003cli\u003eMaximum Line Output: 9.5V into 10kΩ\u003c\/li\u003e\n\u003cli\u003ePhono Slew Rate: Greater Than 250V\/µs\u003c\/li\u003e\n\u003cli\u003eLine Stage Slew Rate: Greater Than 50V\/µs\u003c\/li\u003e\n\u003cli\u003ePower Consumption: Approximately 5W\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eDIMENSIONS\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003e\u003cspan style=\"font-weight: 400;\"\u003e13.9\" x 9.6\" x 5.2\" (Length x Width x Height)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003e\u003cspan style=\"font-weight: 400;\"\u003eWeight: 13.2 lbs\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eINPUTS\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eTape L\/R x2 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eEqualizer L\/R x1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003ePhono L\/R x1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eGND x 1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eTuner L\/R x1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eAux L\/R x1 (back)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eOUTPUTS\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eTape L\/R x2 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eEqualizer L\/R x1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eMain Output L\/R x1 (back)\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eAC Outlets x 6 (back)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cb\u003e\u003ci\u003eMANUFACTURER\u003c\/i\u003e\u003c\/b\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eMFD. 1978\u003c\/li\u003e\n\u003cli style=\"font-weight: 400;\" aria-level=\"1\"\u003eMade in USA\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SpenCertified","offers":[{"title":"Default Title","offer_id":67808416923892,"sku":"CART 1","price":999.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1683\/2705\/files\/IMG_5239.jpg?v=1792100997","url":"https:\/\/spencertified.com\/products\/agi-model-511-vintage-high-speed-stereo-preamplifier-mm-phono-stage-1978","provider":"SpenCertified","version":"1.0","type":"link"}