Description: MANUFACTURER'S SPECIFICATIONS:- "Hiss" Reduction: Up to 30 dB above 5 kHz, 5 to 14 dB total above 400 Hz, depending upon program material and control settings. - Frequency Response: Minimum bandwidth, -3 dB @ 500 Hz, -10 dB @ 1 kHz, -20 dB @ 2.5 kHz; Maximum Bandwidth, ±0.5 dB, 10 Hz to 20 kHz. - Input Level: 0.77 V (0 VU), adjustable to 10 dB lower level. - Maximum Input: 6 V @ 0.1 dB gain. Rated Output: 2.5 V (+10 dB). - Clipping Level: 6 V. Output Impedance: 50 ohms, d.c. coupled. - Gain at 1 kHz: 0 dB adjustable to +10 d B. - THD (Sensitivity at Maximum): 0.2 per cent at any frequency from 20 Hz to 10 kHz. - IM Distortion: 0.05 per cent. - Internal Noise: 100 µV rms. 20 Hz to 20 kHz. - General Specifications Dimensions: 171/2 in. (44.5 cm) W x 2'/, in. (7.3 cm) H x 8% in. (21 cm) D. - Weight: 8 lbs. (3.6 kg). - Power Requirements: 105-125 V, 50/60 Hz, 8 W From 1978 Audio Magazine: The Burwen Research DNF-1201A is a much improved and totally restyled and re -engineered version of Dick Burwen's earlier Model 1201 which we had an opportunity to examine some years ago. The Burwen operation is now headquartered at the same location as KLH, in Cambridge, Mass., both companies being part of EAD Industries. Evidently, with Mr. Burwen now able to devote all his efforts to engineering (instead of trying to run his small, independent company and worry about new products all at the same time), he has come up with a truly effective dynamic noise filter. A dynamic noise filter, unlike the more familiar "high cut" passive filters found on most preamplifiers, amplifiers, and even receivers, may be thought of as a filter whose cut-off points and degree of attenuation are constantly changing, depending upon the musical content of the program source. In other words, if a moment of music comes along which contains no high frequencies, the filter cuts down overall system response (it is usually inserted in the signal path via the tape out/tape in jacks available on most amplifiers and receivers), and high frequency "hiss" or noise is sharply diminished. At the instant when a high frequency musical signal comes along, the filter "opens up" and lets the music come through unattenuated. Sounds simple, but execution of an unobtrusive dynamic filter is not that easy. As for what happens to hiss when the filters are wide open and highs are contained in the music, a well known characteristic of human hearing known as the "masking effect" takes care of that very nicely. During such time periods, the high frequency musical content tends to mask the lower intensity high -frequency noise so that even though it is very much there, our ears simply do not res- pond to it.
Price: 119 USD
Location: Woodstock, Illinois
End Time: 2024-02-29T18:14:38.000Z
Shipping Cost: N/A USD
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Item Specifics
All returns accepted: ReturnsNotAccepted
Brand: Burwen
Type: Vintage Dynamics Processor
Model: 1201A
Country/Region of Manufacture: United States
