• Country
• United States of America (USA)

• Manufacturer / Brand
• dbx Inc.; Waltham (MA)

• Year
• 1980 ?

• Category
• Miscellaneous (Other, Various) - see notes

• Radiomuseum.org ID
• 300343

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Transistors
• Semiconductors present.

• Semiconductors

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 115/240 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: Dynamic Range Enhancer 117 - dbx Inc.; Waltham MA

• Shape
• Book-shelf unit.

• Dimensions (WHD)
• 3 x 5 x 9 inch / 76 x 127 x 229 mm

• Notes

• Compression & expansion: continuous from 1.4 compression slope (14 dB output change/20 dB input change) to 2.0 expansion slope (20 dB output change/10 dB input change)
  Dynamic range: 120dB input or output
  Input noise: -110 dBm typical, -100 dBm maximum
  Input level: maximum input signal in excess of 30 Volts RMS
  Input impedance: 50K ohms
  Output level: maximum output 10 Volts RMS open circuit; +17 dBm into 600 ohms
  Output impedance: 500 ohms
  Distortion: 0.5% maximum @20 Hz, 0.2% typical above 50 Hz for complete cycle of compression and expansion; 1.2% @20 Hz for 2:1 expansion; .05% typical @ 1 KHz and above for any setting of controls (3 Volts RMS or less input or output.)
  Frequency response: +0, -1dB 20 Hz to 20 KHz
  Attack time: 50 dB/m Sec maximum initial attack rate @1.4 expansion. 12 mSec to 65% of final value @ any setting of compression or expansion. Adjusted to be within integrating time of human ear within the constraints of reasonable low frequency distortion.
  Release (decay) time: constant rate 140 dB/sec (norm) or 50 dB/sec (slow) @ 1.4 expansion
  Level match control: unity gain point may be varied from 100 mV to 1 Volt

  Power consumption:
  USA model 115 VAC 50-60 Hz 2 Watts
  EU model 240 VAC 50-60 Hz 2 Watts

  Power supply switched by shortening inputs on transformer.

• Net weight (2.2 lb = 1 kg)
• 4.5 lb (4 lb 8 oz) / 2.043 kg

• Author
• Model page created by Bartosz Szwed. See "Data change" for further contributors.

• Other Models

• Here you find 26 models, 25 with images and 4 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from dbx Inc.; Waltham (MA)