UREI 537 1/3 Octave Graphic Equalizer, sn1253A

UREI Model 537 One Third Octave Equalizer. Fully tested, working, please see full description.
Disponibilité: Rupture de stock

UREI (United Recording Electronics Industries) made some very good gear.  These are well designed pieces that were ubiquitous in Recording Studios in the 70s and 80s, often used as monitor equalizers.

Now they're often found as outboard EQs, and are still quite useful.  Unfortunately the quality of the faders is poor. The faders get a bit sticky, and in some cases they will freeze completely.  

The faders on these UREIs have been degreased, relubed and retreated with Caig lube and they are operable.  However the feel remains uneven and jerky.

The Fader caps on these units had a habit of disintegrating and the caps on these units have been removed.

These EQs have been fully tested and all of the faders function, though some remain sticky.  

The cosmetics are very good, with a dark spot on the top cover, and two areas along the top edge of the front panel that are scratched.  The Front panel has a few faint ink marks.  The areas around the rack mount holes are in good condition.     


INPUT: Balanced bridging, differential amplifier
INPUT IMPEDANCE: 40 kohms, used as balanced input.
                               20 kohms, used as unbalanced (single-ended) input
MAXIMUM INPUT LEVEL: +20 dB (7.75 volts)
EQUIVALENT INPUT NOISE: Less than -90 dB.  Typically -94 dB; 15.7 kHz bandwidth with all controls set flat, output terminated with 600 ohm load
GAIN: from unity to +20 dB, ±1 dB
FREQUENCY RESPONSE: ±1 dB, 20-20,000 Hz (with no EQ)
OUTPUT: Floating, transformer isolated
OUTPUT LOAD: 150 ohms or greater
POWER OUTPUT: +24 dBm into 600 ohm load (12.28 volts), +26 dBm into 150 ohm load (7.75 volts)
DISTORTION: Less than 0.5% THD, 30 Hz to 15 kHz at maximum rated output

POWER REQUIREMENTS: 100-125 VAC or 200-250 VAC, 50/60 Hz, switch selectable, less than 10 W
ENVIRONMENT: Operating 0°C to +50°C (+32°F to +122°F); storage -20°C to +60°C (-4°P to +140°F)

FILTER TYPE: 27 individual L-C type active filters
FILTER BANDWIDTH: 1/3-octave at -3dB points with 8 dB boost or cut
CENTER FREQUENCIES: Standard ISO (Hz) 40 50 63 80 125 160 200 250 315 400 500 630 800 1K 1.25K 1.6K 2K 2.5K 3.15K 4K 5K 6.3K 8K 10K 12.5K 16K
FREQUENCY ACCURACY: ±3% of center frequency
RANGE OF BOOST AND CUT: 0 to ±12 dB, single filter section

CALIBRATION OF BOOST AND CUT: Within 1 dB of indicated setting, 0 to ±5 dB, Within 1.5 dB of indicated setting, ±5 to ±12 dB, single filter section

EQUALIZATION: 27 vertical slide controls, continuously variable 0 to ±12 dB.
GAIN: Screwdriver adjustable from unity to +20 dB
EQ IN/OUT: Front panel toggle switch
POWER: Front panel toggle switch
INDICATORS: LED, Power ON; LED, Overload Condition, levels monitored at 4 circuit points

MAINS VOLTAGE: Rear panel slide switch, 115/230 volts.

CONNECTIONS: Input and output, through rear chassis barrier strip; Power through 3-wire power cable