Delta Electronics, Inc.

Model SNG-1 Stereo Noise Generator

Stereo Noise Generator


  • Selectable white, pink and USASI noise spectra
  • Generates true stereo noise (uncorrelated)
  • True balanced front and rear panel outputs
  • Compact Size
  • Low DC offset
  • Close Channel Tracking (better than 0.5 dB)
  • External input offers unlimited noise envelopes
  • Outputs can drive either 600 or 50 Ohms
  • Meets FCC/NRSC and Canadian D.O.C.


Although a variety of noise generators are available, pricing and features vary widely. Many generators offer portability and low cost at the expense of accuracy. More expensive "laboratory" type noise generators offer high performance and more features, but are often beyond the budget of the broadcast or recording facility. The Delta Model SNG-1 Stereo Noise Generator offers a number of "laboratory" type features and noise weightings in a very affordable and compact package.


The Model SNG-1 provides true stereo white, pink and USASI noise spectra in either continuous or pulsed output modes. The output amplitude is controlled by either a front panel control, an external input, or an internal pulse generator. The external input amplitude modulates the noise output level, providing full user control over the noise output envelope. By varying the parameters of the external control signal, an unlimited variety of noise envelopes is possible. Alternately, the fixed internal pulse generator creates a stand-alone pulsed noise source which accurately simulates program dynamics.

The output select control provides seven versatile combinations of left and right channel noise for alignment and troubleshooting:


The SNG-1 provides a number of uses in the studio environment. The rear panel XLR connectors facilitate frequency response and recorder head alignment tests, while the front panel tip-ring-sleeve jacks provide quick routing to any piece of equipment via studio patch bays. In multi-studio environments, assignment of the SNG-1 to a common distribution amplifier bus offers the selected noise to all studios. The SNG-1 speeds the completion of new studio facilities, serving as a pulsed noise standard for room reverberations and frequency response measurements. The unique "clipped" output quickly verifies signal paths as you check for phasing errors or channel reversals. The SNG-1 also makes audio processor adjustments easier and more precise; the USASI frequency response, combined with NRSC channel blending and the internal NRSC pulsed mode, provides repetitive bursts of noise. These bursts more accurately simulate program dynamics, spectral content and channel blending. This eliminates the hit-or-miss adjustments that result from using constantly changing program material.

The SNG-1 also satisfies several test and alignment requirements at the transmitter site. The frequency response of program lines, STL equipment and exciters may be easily checked. The SNG-1 permits quick adjustment of the equalization filters in an AM Stereo Exciter. The SNG-1 can be used to dynamically align processing equipment in AM, FM or TV applications. The left-only and right-only outputs are useful for making wideband separation measurements. Similarly, the mono (L = R) and subchannel (L = -R) outputs allow crosstalk measurement. The broad spectrum of noise can be used to adjust transmitter tuning and loading controls to minimize incidental AM components in FM transmitters. The SNG-1 also meets the requirements of National Radio Systems Committee (NRSC) standards NRSC-1 (EIA-549-1988) and NRSC-2 for testing AM radio transmission facilities. The SNG-1 can also be used for testing to the Canadian D.O.C. requirements for occupied bandwidth of AM Stereo stations (Supplement RSS-150, section 3.22). The Stereo Noise Generator complements the Delta Model SM-1 AM Splatter Monitor to provide a very clear picture of compliance with the FCC RF Bandwidth limitations (47 CFR 73.44).

Stereo Noise Generator - Rear Panel

Amplitude Distribution:Gaussian and Random
Peak to RMS Ratio:Capable of > 4:1 to full rated output
Noise Weighting: White: 20 Hz to 20 kHz: ±1 dB; 20 Hz to 50 kHz: ±3 dB
Pink: -3 dB/Octave 20 Hz to 20 kHz: ±1 dB
USASI: +6 dB/Octave 100 Hz high pass and -6 dB/Octave 320 Hz low pass: ±1 dB
Connectors: Rear panel duel XLR balanced outputs
Front panel dual stereo phone jack balanced outputs
BNC input for external amplitude control - continuously variable from 0V (off) to +5V (full output)
IEC standard line cord receptacle
3AG fuseholder (1/4 Amp standard-blow fuse)
Output Selections: Stereo (independent left and right)
Mono (L = R)
Left only
Right only
NRSC (subchannel 3 dB below main channel)
Subchannel only (L = -R)
Clipped (L = -R with clipped peaks on L+ and R-)
Output Level: >+10 dBm into 600 Ohms balanced
>0.5 Vrms into 50 Ohms unbalanced
<10 mV DC offset

Output level adjustable by front panel control

Output Level Tracking:Within 0.5 dB between channels
Turn On Time:8 seconds after application of power
Output Impedance:Approximately 25 Ohms balanced, 12 Ohms unbalanced
Pulse Output: NRSC: 2.5 Hz rate at 12.5% duty cycle with 20 dB peak to average ratio
External: Amplitude controlled by external signal (EXT GATE)
Continuous: Not pulsed (CW)
Line Voltage:120/240 VAC ±10%, 47 to 63 Hz (line voltage selected by internal jumpers)
Size:7.3 inches (185 mm) wide x 2.6 inches (66 mm) high x 9.9 (262 mm) deep
Weight:3 lbs 14 oz. (1.76 kg)
Operating Temperature:0 to 50º C ambient
Order Numbers:
  Model SNG-1 Stereo Noise Generator, 120 VAC:  915-0019-001
  Model SNG-1 Stereo Noise Generator, 240 VAC:  915-0019-002
  Model RMK-1 Rack Mount Kit:  942-0064-001

For additional information on any of our products, please contact Sales to discuss your particular requirements:
Delta Electronics, Inc.
5730 General Washington Drive
P. O. Box 11268
Alexandria, VA 22312
Phone: (703) 354-3350
U.S. Toll Free: 1-800-8-DELTA-8 (1-800-833-5828)
Fax: (703) 354-0216

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