ST-PH1 Phono Preamplifier The phono preamplifier shall be an RDL ST-PH1. The unit shall provide one stereo unbalanced input and one stereo balanced output. The input shall be phono-level and the outputs shall be professional line-level. The left and right unbalanced inputs shall have a nominal input impedance of 47 kOhms. A single-turn trimming control shall be provided to set the circuit gain to a value between 40 dB and 60 dB at 1 kHz. The unit shall provide an audio frequency response that follows the RIAA curve with total harmonic distortion plus noise <0.03% (10 Hz to 30 kHz) and a noise floor exceeding 75 dB below the normal rated output level. The unit shall provide headroom of no less than 18 dB above the normal rated output level. The unit shall provide line-level balanced audio outputs at a nominal rated output level of +4 dBu with an output impedance no greater than 300 O. The output circuits shall be configured to produce an unbalanced output of proper phase between the positive output leg and ground. Two outputs shall be provided, left and right. The unit shall be constructed in an electrically non-conductive, thermally conductive enclosure. Internal circuitry shall be protected from moisture and vibration using a thermally conductive compound that permanently secures the circuitry within the enclosure. The face of the unit shall provide graphical labels identifying wiring connections and operating controls. Indicators and controls shall be oriented toward the face of the unit. Connection to external wiring shall be provided using a fixed terminal block on the edge of the unit. The terminal block shall accept wiring gauges from 14 to 22 and shall include a positive electrically conductive mechanism to prevent wire abrasion by the terminal screws. The unit shall measure 3” (7.6 cm) x 1.6” (4 cm) x 0.7” (1.7 cm) and be compatible with all RDL STICK-ON mounting accessories. The unit shall be supplied with a two part re-closable polypropylene fastener system equipped with a rubber adhesive that bonds to low surface energy materials. The unit shall be equipped to operate from either 24 Vdc ground-referenced power or from bipolar ± 12 Vdc or ± 15 Vdc power with a maximum current not exceeding 60 mA. The unit shall utilize an external power supply and shall be equipped to operate from 24 Vdc ground-referenced or bipolar ± 12 Vdc or ± 15 Vdc power. The unit shall be engineered, assembled and tested in the U.S.A. and be specified for continuous duty in professional installed systems. The unit shall be specified for operation in an ambient temperature between 0 and 55 degrees C. The unit shall comply with relevant EMC requirements and shall bear the CE marking. The unit shall be an RDL ST-PH1.