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Pro-Sound Defender
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Every technician or professional musician has faced it before or soon will… “The dreaded” humming from the speakers, that can drive you completely crazy, a telltale sign of ground loop problems. Ground loops are caused by ground potential differences in your equipment.

Now, you can STOP” ground loops by using the AGL-PSD Series of Pro-Sound Defenders without any need for ground filters and phase invertors. This rugged, yet sleek and portable in-line product is perfect for professional audio users allowing them to just plug it directly into the inputs or outputs of their equipment.

Pro-Sound Series

The Pro-Sound Defender totally outperforms all the industry leading inline isolation transformers. These are a high quality, totally passive audio transformer that will isolate the input and output signal grounds, thereby reducing hum & ground loop noise. This high performance transformer has extremely flat and wide frequency response and can handle high signal level while maintaining an isolated balanced output. AGL-PSD-1 has ground lifter switch has three positions to solve any combination of grounding problems. Both AGL-PSD-1 & AGL-PSD-2 give a very clean and neutral sound with a wide variety of signal sources. They are designed to be used with impedances from 600 Ohms to 10K Ohms.


  •  Perfect for Pro-Sound applications, Studios, Concerts, Garage bands, etc.

  •  Eliminates noise interference in line level applications, such as a connection between a microphone and a mixer or a connection between a mixer and an amplifier

  •  Removes Ground-Loop, Mode Noise and differentially-induced Hum

  •  Rugged, Compact In-Line device

  •  Flat and wide frequency response from 3 Hz to over 100 KHz

  •  Handles high signal levels

  •  Totally transparent, Distortion-Free

  •  Gives clean and neutral sound

  •  Excellent Signal Fidelity

  •  Easy to Use, Passive devic  Available in both XLR connectors and ¼” Phono connectors

AGL-PSD-1 Dimensions

PSD1 Dimensioins

AGL-PSD-2 Dimensions:

PSD-2 Dimensions

All transformers in the AGL-PSD series are true isolation transformers that are designed with flat frequency response and wide bandwidth, which provides linear response and distortion–free audio with excellent pulse fidelity.

AGL-PSD series will stop hum, buzz and line balance problem. The 3–position switch on AGL-PSD-1 will eliminate the need to cut pin “1” to lift the audio ground and the connection to shield.

PSD Circuit
  • SWITCH POSITION 1: Chassis shield connected.
    Audio ground not connected. Acts as a balanced line transformer to break ground loops.

  • SWITCH POSITION 2: Chassis shield and audio connected. Corrects balance on audio lines.

  • SWITCH POSITION 3: Chassis shield and audio connected. Breaks ground

Allen Avionics has Hum Eliminators and Isolation Transformers for SDI, HD-SDI, S Video, NTSC, Composite, HDTV Analog (Y, Pb, Pr or RGB), Component, Y R-Y B-Y. They can be used in any brand of Audio or Video equipments

For additional technical information or ordering information call our technical sales department at 516-248-8080. You can also see us at www.allenavionics.com or Email any questions you may have to sales@allenavionics.com.

Allen Avionics, Inc.
2727 Clinton Street
River Grove, IL  60171
Phone: (708)-453-3238
Fax: (708)-453-0297
E-Mail: Sales@AllenAvionics.com

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