An extremely low-noise preamp capable of working with line level or instrument level signals, is followed by four sections of EQ combining a two position high pass filter with three parametric bands, each with its own set of carefully tuned frequency presets. An internal jumper can turn the DocDerr into an unparralled instrument preamp with 16dB of gain, ideal for acoustic guitar, bass, synths, exotic plucked instruments, etc.
The versatile EQ is followed by a unique dynamics section which offers renowned Empirical Labs compression at an unprecedented price, and an extremely musical tape emulation circuit that softens and tames high frequencies and transient spikes. We believe it’s the best single knob “knee” compression available in this format.
One of the pivotal features of the DocDerr is the “Mix” knob which allows the user to blend the uncompressed EQ’s signal with the compressed and saturated signal. This parallel compression technique, used by top recording and mixing engineers for many years unlocks a whole world of sonic possibilities.
Like all ELI 500 series modules, the EL-Rx is available with either horizontal or vertically oriented front panel configurations, and is “Linkable” for using our famous compression on stereo sources.
Specifications:
• Six digitally controlled sections of analog processing
• Frequency response - 3 Hz to 180 kHz on eq section (-3dB points).
• Dynamic range - 120 dB from maximum output (.5%THD soft clipping) to minimum output. Noise floor with Mix on 0 is typically – 91dBu.
• Distortion range - between .0006% and 10% at 1KHz, depending on mode and settings.
• Maximum Input before hard clipping - +22dBm, “ Line In” mode. Maximum Output (Mix at 0) - +28.5dBm
• Compressor Dynamics Time Constants - Attack time is around 1mS. Release .2 sec, fixed internally. Stereo Linkable for stereo tracks. With the EL500 powered rack, the push of a button enables linking.
• Input Impedance - 120k Ohm, Instrument In Mode, output impedance is less than 75 ohms. 20K input impedance in balanced Line in mode.
• Guitar adaptor cable included
An extremely low-noise preamp capable of working with line level or instrument level signals, is followed by four sections of EQ combining a two position high pass filter with three parametric bands, each with its own set of carefully tuned frequency presets. An internal jumper can turn the DocDerr into an unparralled instrument preamp with 16dB of gain, ideal for acoustic guitar, bass, synths, exotic plucked instruments, etc. 
