GNR1 digital audio noise filter is an audio processing device integrating digital
noise reduction and digital filtering. It can be widely used in the external audio
processing sector of all types of wireless receiving equipment such as radio
transceiver, receiver, radio, to effectively reduce the background noise, improve
the signal-to-noise ratio, and improve the signal identifiable degree. GNR1
supports to connect external passive speaker, which can provide 3W audio output
power; support independent adjustment of input/output sound volume; support
selection of high/low input impedance; support audio double output ports (3.5mm
stereo output, RCA output); support headphone output and automatic switch of
headphone/speaker output.
II. Basic Indicators
Digital denoiser SNR upgrade degree: More than 22dB
Digital filter frequency response range: L-CUT adjustment range: 5Hz-1280Hz
H-CUT adjustment range: 500Hz-5615Hz
Headphone driving power:100mW@Max
Headphone output impedance: 16~64Ω
Input impedance range: Low impedance of 16Ω, high impedance of 10kΩ
Speaker output power:≥3W (8Ω, THD≤0.2%)
Speaker output impedance:4~16Ω
Operating voltage:DC12V:t15%
Volume:159*44*143mm
III. Operating Instruction
3.1 Description of Panel
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Chongqing Xiegu Technology Co., Ltd.
Front panel
Rear panel
3.2.1 Wiring
The input is a mono channel, and its interface is a 3.5mm stereo jack. Two tracks are
connected by the internal wiring. Do not use the mono channel jack, or you will cause
a short circuit and no sound to the input!
The output is also a mono channel, with two jacks: RCA jack, 3.5mm stereo jack. This
stereo interface also connects two channels in the device. Do not use the mono
channel jack, or you will cause a short circuit and no sound to the output!
The external power is DC 12V ± 15%, you can directly use the 13.8V power of the
radio equipment to supply power for this.
●Do not use it under over-voltage! Do not directly power with 220VAC!
3.2.2 Selection of input impedance. Reasonably select the high/low input impedance
level for GNR1 according to the audio output impedance of the device you are using.
You may turn down the output sound volume if you select it improperly.
3.2.3 Adjustment of input sound volume. You can adjust to the appropriate sound
volume to keep a proper output sound volume and distortionless sound quality. You
can adjust it in cooperation with the output sound volume. If the input audio amplitude
is so high that the input is overloaded, the CLIP indicator on the panel will be on, so
you should turn down the input sound volume at this time.
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Chongqing Xiegu Technology Co., Ltd.
3.2.4 Adjustment of output sound volume. The knob controls the output sound
volume of the speaker and headphone. You can adjust to an appropriate output sound
volume without distortionless sound quality. If you need to use headphones to monitor
the output, it is recommended to turn the knob left to the lowest sound volume, and
then insert the headphones to avoid damage to your hearing due to too loud sound.
●After inserting the headphone, the speaker output will be automatically cut off.
3.2.5 NR noise reduction adjustment. This knob controls the NR noise reduction
switch, and the 200-level noise reduction degree. Turn left to the end to turn off the
NR. Turn to right to turn on NR noise reduction and increase the noise reduction
degree by levels.
●NR noise reduction will cause slight volume loss, so please reasonably adjust
the noise reduction degree to get a comfortable listening experience.
3.2.6 Adjustment of the digital filter. The digital filter can be adjusted by L and R,
indicating the L-CUT low cut and H-CUT high cut adjustment. Turn the L knob left to
the end, and the L-CUT low cut will be turned off. Turn the H knob right to the end,
and the H-CUT high cut will be turned off.
Schematic Diagram of Filter Composition:
As shown in the figure on the right, the filter
consists of L-CUT and H-CUT, and both work
together to form an effective filter bandwidth.
L-CUT controls the low boundary frequency,
which can effectively cut off the low-frequency
component;
H-CUT controls the low boundary frequency,
which can effectively cut off the high-frequency
component;
In daily use, adjust according to your own
listening preferences, subject to getting the best
listening effect.
*Note: If the actual bandwidth of the filter is less than the useful bandwidth of the
useful signal,