STA-1M Line-Level Preamplifier
The audio line amplifier shall be an RDL STA-1M. The unit shall provide an audio preamplifier equipped with one line-level balanced input, one line-level balanced output, one line-level unbalanced output and a single-turn gain trimmer. The input shall be fully compatible with unbalanced wiring configurations. 

The input shall be active balanced bridging with a nominal input impedance of 10 kOhms and shall be fully compatible with either an unbalanced or balanced audio source. A single-turn trimming control shall be provided to set the gain. The unit shall be capable of negative gain.  For a balanced output connection, the nominal gain range of the GAIN trimmer shall be -7 dB to +14 dB. For an unbalanced output connection, the nominal gain range of the GAIN trimmer shall be -14 dB to +7 dB. 

The unit shall provide an audio frequency response of 10 Hz to 20 kHz (± 0.25 dB) with total harmonic distortion plus noise  less than 0.05% and a noise floor exceeding 75 dB below the normal rated output level. The input shall provide common mode rejection greater than 50 dB from 50 Hz to 120 Hz. The unit shall provide headroom of no less than 18 dB above +4 dBu. 

The unit shall provide a line-level balanced audio output at a nominal rated output level of +4 dBu with an output impedance no higher than 150 O. The unbalanced output shall be 6 dB lower in amplitude than the balanced output.  The unit must simultaneously drive loads connected to both outputs.

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. 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 50 mA. The unit shall utilize an external power supply. 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 STA-1M.