The 2U EQP-1S3-SS is an enhanced version of the EQP-1A3. The EQM-1S3 (mastering version) takes the EQP-1S3 one step further by replacing the BOOST/ATTEN potentiometers with 21-position (and BW with 11-position) ELMA switches, loaded with precision metal film resistors to achieve custom tapers for each control and this solid-state line amp version of the EQM-1S3 has exactly the same front end (input transformer and passive EQ section) but utilise a solid-state opamp (API 2520) gain stage driving a Triad output transformer, just like the originals. The current design implements our "full-range, progressive-taper" design, which provides 0.5 dB per step precision for the first 50% of rotation and then progressively larger (1 or 2 dB) steps as the control is rotated from 50% to 100% of rotation. This allows precise control for subtle equalization for mix bus or similar applications or the full 18-20 dB BOOST/ATTEN of the potted version when tracking or mixing of individual tracks. Furthermore, the stepped controls make recall a breeze and the precise tracking between units is essential for stereo image retention when using a pair on the stereo mix bus. 30, 40, 70, 100 CPS shelf boost, 0 - 13.5 dB 30, 40, 70, 100 CPS shelf attenuate, 0 - 17.5 dB 1, 2, 3, 4, 5, 8, 10, 12, 16 KCS peak boost, 0 - 18 dB; 5, 10 KCS shelf boost, 0 - 14 dB 5, 10, 20 KCS shelf attenuate, 0 - 16 dB Input Impedance: ~600 Ohms Output Impedance: ~50 Ohms Noise: Below -80 dBm Distortion: ≤ 0.15% at 10 dBm into 600 Ohms Amplifier: 20 CPS to 20 KCS; +0, -1 dB ref 1 KCS including input/output xfmrs Output Level: +21 dBm maximum
