The new GAP Dual In-Line DSP noise eliminating module provides two channel/stereo noise
cancellation, and is suitable for use on all radios and receivers including SDR, especially those
with stereo or two channel output options. It can also be used with standard mono speaker input
and output signals.
The Dual In-Line module incorporates GAP’s new dual DSP noise cancelling module, which has
an improved noise cancelling algorithm that brings even better quality audio to the listener when
operating in very noisy conditions.
The processed speech is clearer and more intelligible as a result. The module caters for both
high and medium level audio input signals, and has stereo line out, stereo headphone and mono
speaker output sockets, making it very flexible for the user. You can listen with headphones and
a mono speaker at the same time, and you can also connect a pair of stereo computer speakers
to the line output socket allowing you to monitor two separate channels at the same time.
Two input connections are provided to allow the user flexibility in their choice of input level and
termination impedance. “Audio In” (speaker) and “Line In” sockets are located on back of the
unit and are identified by arrows. “Audio In” (Speaker Level) – This is for a 3.5mm mono or
stereo speaker connection. The input is terminated with a low impedance load (8 Ohms) and
appropriate attenuator to handle speaker level signals correctly. “Line In” – This is used for
other input devices such as low level devices like MP3 players and PC line outputs or line level
from an SDR radio. This is terminated at around 10kOhms.
There are two level controls for the device outputs. The “Line Out Level” control adjusts the Line
output level only, while the “Audio Output Level” controls the listening volume for both the
headphone and the (mono) speaker output.
Operating voltage: 10 to 16v d.c.
Power Connection: 2.1mm Power Jack
Audio Input Input – Stereo (Audio 1 – Plug Tip/ Audio 2 – Plug Ring)
8 Ohms at 2Watts RMS
10K Ohm at 600mV p-p
Audio Outputs: Headphones/small speakers – 0.5 + 0.5 Watts into 8 Ohms
Speaker – Greater than 6 Watts into 8 Ohms
Line – Stereo 600 Ohms at up to 0dBV
Connections: Audio Inputs – 3.5mm Stereo Jack Socket
Line and Headphone Outputs – 3.5mm Stereo Jack socket
Mono Speaker output – 3.5mm Mono Jack socket
Power 2.1mm Coaxial Power Jack – Centre Pin = +Ve,
Controls: Audio Input Level
Combine/Separate signal switch
DSP Filter Level 1 – 8 (9 to 35dB)
Off/On/DSP Noise Cancelling On
Audio Out Level (For a speaker and for headphones)
Line Out Level
Indicators: Power ON
Noise Cancellation ON
Channel 1 Overload
Channel 2 Overload