Program equalizer, mastering · Tube · 2U / 19 in

EQM-1S3

Pulse Techniques · Fort Collins, Colorado
In use

As described on the EQP-1S3 product page, the 2U EQP-1S3 is an enhance 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.

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.

Specifications

  • 30, 40, 70, 100 CPS (Hz) shelf boost, 0 – 13.5 dB (FRPT stepped control, 0.5 dB steps 0–5 dB)
  • 30, 40, 70, 100 CPS shelf attenuate, 0 – 17.5 dB (FRPT stepped control, 0.5 dB steps 0–5 dB)
  • 1, 2, 3, 4, 5, 8, 10, 12, 16 KCS (kHz) peak boost, 0 – 18 dB (FRPT stepped control)
  • 5, 10 KCS (kHz) shelf boost, 0 – 14.5 dB (FRPT stepped control)
  • 5, 10, 20 KCS shelf attenuate, 0 – 16 dB (FRPT stepped control)
  • Input Impedance: ~600 Ohms
  • Output Impedance: ~50 Ohms
  • Noise: 92 dB below +10 dBm
  • Distortion: ≤ 0.15% at +10 dBm into 600 Ohms
  • Amplifier: Flat, 20 CPS to 20 KCS, +/- 0.5 dB
  • Tubes: 1 ea 12AU7, 12AX7, 6X4
  • FRPT = full-range, progressive-taper. Step size increases beyond 50% rotation.