The pictured item is a silver RDQ-1 by Z-Systems, also known as the Z-Sys RDP-1 (RDQ-1's identical big sister with more inputs and outputs). It was once Stereophile Magazine's digital product of the year.
It is a digital preamplifier with four bands digital parametric equalization and two bands of low- and high-frequency shelf control. The RDQ-1 has no analog inputs or outputs. It has a balance control function and the EQ can be used in linked stereo or separate mono channels.
This is a transparent digital EQ that works completely in the digital domain. Designed to be used between your CD Transport or Music Server and your Digital/Analog converter.
Analog EQ introduces distortion and other problems to the signal, which results in loss of transparency. This EQ doesn't have the usual analog equalizer problems and also has the capacity of 99 preset EQ curves.
Use this unit with any music server and you can adjust the sound of a bad recording. It has two inputs, so you can use one with the CD Transport and the other with the Music Server.
The RDQ-1 is identical to the RDP-1 and features six bands (filters) of equalization done entirely in the digital domain for a totally transparent sound. Four of the filters are parametric and independently adjustable across the 25hz-20khz range with changeable boost/cut and bandwidth (Q or slope) parameters.
Once your systems response has been smoothed with the above filters*, the remaining two filters act like sophisticated tone controls with adjustable gain and turnover frequency to compensate for poor recordings.
The RDQ-1 accepts digital sources only and has no internal DAC's, so you must have an outboard digital to analog convertor or source for it to work. It has two inputs (1) AES/EBU and (1) S/PDIF RCA. There are two outputs one each of AES/EBU and S/PDIF RCA.
Here are links to the several articles about the RDP-1:
-Dimensions 16.5" Wide x 3.25" Tall x 10.0" Deep
-Weight 11 lbs.
-Color available in black or silver
-Inputs 1 AES/EBU (transformer-isolated, 110-ohm terminated)
-1 S/PDIF (transformer-isolated, 75-ohm terminated)
-Outputs 1 AES/EBU 1 S/PDIF
-Input/output precision up to 24-bits
-Gain control from -12 dB to +12 dB
-Gain resolution 0.2 dB increments from +12 dB to -12 dB
-Filter types 4 parametric, 2 shelving
-Center frequency resolution 1/6-th octave ISO from 28Hz to 18 KHz
-Filter gain/cut from -12 dB to +12.0 dB
-Filter bandwidths Q = 0.4, 0.8, 1.3, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0
-Shelf filter slopes 6 dB/octave
-Dither types 20-bit and 16-bit proprietary floating-point techniques
-Digital filter architecture proprietary minimum roundoff-noise structure
-Dynamic range better than 144 dB
-Stereo modes Stereo-linked operation
-Number of presets 99 including power up preset
-THD+N better than -135 dB
-Processor type TMS320C31 32-bit floating-point DSP
-Processor performance 60 MFLOPS
-Digital audio demodulator/modulator Crystal Semiconductor
-Sample rates supported 32 kHz, 44.1 kHz, 48 kHz. 88.2 kHz/96 kHz
-Auxiliary-bit status handling unit is transparent to channel status, validity, and auxiliary bits
-Power supply 110/220VAC, 50/60Hz
I have the AC cord. This model didn't come with a remote. Payment via check, money order, or PayPal. Please ask any questions.