JBL UREI 7922 Audio Delay unit

This delay is in excellent working order, cosmetics are good with some wear to the top and bottom covers.  Front panel has a few small impressions in the plastic cover, and the left rack ear shows wear around the top mount.

One complaint is of noisy power transformers, and this unit has an audible buzz from the transformer.  We've retightened the transformer mounting hardware and placed some thin rubber to the top and bottom covers over the transformer with only slight improvement.  

The Audio output on both channels is clean,  quiet and the measured noise is within spec.

The top and bottom covers are attached to the sides of the frame with 3 small screws on each side.  There's a small gap between the covers and the back of the unit because the covers have no hardware along the rear edge, and that gap may contribute to the acoustic hum.  

FEATURES

• 0 to 327 millisecond Audio Delay in 10 microsecond Steps; Equivalent to Approximately 1/8 inch Resolution for Over 350 Feet
• One Input, two Independently Delayed Outputs
• 16 Bit Linear Conversion and Unique Low Noise Analog-to-Digital Converter for Greater Than 90 dB Dynamic Range
• Linear Phase Anti-Aliasing Filter ( + 5: 20 Hz to 20 kHz) for Superb Audio Quality and Sharp Imaging
• Digital Oversampling Filter to Minimize Phase Distortion
• Simplified Headroom Control and Indicator For Easily Optimized Signal-to-Noise Performance
• B [Reference A] Delay Time Display and Reference Output For Precise Array Alignment (Compensates for Internal Propagation Time)
• Non-Volatile Delay Time Memory; Unit Remembers Settings When Power is Off
• Auto-Bypass Ensures Signal Flow if Power is Lost

SPECIFICATIONS

ELECTRICAL
Input: Differential amplifier. May be used balanced or unbalanced. bridging. Impedance 20 k ohm balanced, I0 k ohm unbalanced.
Maximum Input Level: + 22 dBu.
Output (Both Channels): Floating, transformer isolated.
Output Level: + 22 dBm max. into 600 ohm load.
Frequency Response: + 1 dB, 20 Hz to 20 kHz.
Gain: Unity, + I dB.
Dynamic Range: Greater than 90 dB. (15.7 kHz noise bandwidth with 600 ohm load.)
Phase Shift: Less than + 5 degrees, 20 Hz to 20 kHz.
Delay Range: 0 to 327 milliseconds.
Delay Resolution: I0 microseconds per step (High resolution mode).
                             I millisecond per step (Low resolution mode)
Digital Conversion: 16 bit, linear
Sampling Rate: 50 kHz
Power Requirements 105 to 125 VAC, 60 Hz, 30 W max
Environment Operating, 0°C to + 50°C
Storage, -20°C to + 60°C
INDICATORS
Headroom: One red LED labeled ‘Clip’ and three green LEDs labeled ‘IO: ‘20: ‘30’ to indicate signal level below clipping
Delay Time: Three digit LED display in normal resolution mode. Five digit display in high resolution mode
Display Modes: A channel delay time, B channel delay time, B channel delay time referenced to A
CONTROLS
Headroom: Single knob adjusts internal input and output gain for best signal-to-noise ratio
DISPLAY Pushbutton: Steps through three display modes
                                   A output delay time
                                   B output delay time
                                   B [reference A] delay time
TIME SET Pushbuttons. Change time setting of either A or B output
HI-RES Pushbutton Selects Hi-Resolution (IO microsecond) or normal resolution (I millisecond) for display and control Also, holding HI-RES button in for 5 seconds locks out the TIME SET buttons for security Hold down HI-RES again to release security
POWER: Front-panel mounted ON/OFF switch
CONNECTIONS (Rear Panel)
Input: Female XL and barrier strip
Outputs: One Male XL and barrier strip connection for each output (A & Bl
Ground: Audio ground to chassis ground removable strap