New DF330 Universal Noise Filter from Drawmer
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(Click for a close-up) |
August 11, 2002
Drawmer is now shipping the new, two-channel, "single ended' DF330 noise filter. Like its predecessor the DF320, the DF330 requires no encode/decode process. Combining three different single ended audio processes, the DF330 reduces high frequency noise, reduces low frequency rumble and reduces broadband background noise during momentary silences in program.
The first process in the new Drawmer DF330 is a unique frequency controlled Low Pass Filter circuitry that sets itself to open and close bandwidth to the highest frequency of input audio. This variable filter process tracks regardless of fade ins/outs or changes in program dynamics. The automatic nature of this filter design makes the DF330 good for reducing non-program high frequency noise without any user interaction. A nine segment LED shows the high frequency cut off of this auto filter. A manual mode is available for the user to set individualized cut off frequency if desired.
The second process within the DF330 is a new downward expander section used for reducing up to 40dB of broadband noise during momentary silences in the program. When a program ends, the downward expander reduces gain by up to 40dB maintaining silence. When the program begins, the expander release restores full gain. The new DF330 expander incorporates Ivor Drawmer's "Program Adaptive" process, improving performance with fewer expansion artifacts, quicker reaction time and less noise leak at the start and end of silences in program. The attack time of the expander is self-setting and the release times are variable with and a five segment LED gain reduction meter.
The third main feature of the DF330 is a custom designed "rumble" filter centered at 50Hz with an 18dB per octave slope. This rumble filter can eliminate low frequency noise from outside traffic, HVAC and other low frequency artifacts. It also eliminates low-end content issues that influence compressor operation downstream, such as broadcast on-air processing and satellite uplink processing.
Noted Brad Lunde, president of Transamerica Audio Group, "Let's face it, even the best facilities must work with inconsistent audio material sent from any number of sources. The DF330 is designed as a low cost package to extract good audio from what would otherwise be unusable or of very low quality. A single ended DF330 solution is a practical solution since it can be inserted anywhere in the signal chain to address noise."
In addition to the above features, the DF330 has an overall bypass switch, rumble filter bypass, separate expander bypass and variable filter bypass, plus a stereo link switch. Inputs and outputs are both -10 (1/4 inch unbalanced) and +4 (XLR balanced) so outputs from -10 tape machines can be de-noised and converted to +4.
MSRP: $1099.00 For more information, visit their web site at www.transaudiogroup.com. | 
