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Audio Ground Loop Isolation Transformers
pg AVI_Trans/agl
Download a printable AGL 2 page datasheet in Adobe pdf format
For Professional Audio Applications


  • Easy to Use
  • True Isolation Transformer
  • Distortion-Free
  • Low Signal Loss
  • Excellent Signal Fidelity
  • Ten Times Audio Bandwidth
  • Passive Device
  • Ground Lifter Switch on 600 Models
  • Shielded Transformer Core
  • 1:1 Turns Ratio



Part No. Impedance Bandwidth Isolation Insertion
Package Input
H x W x D
AGL-10K 10 K Ohms
Input & Output
300 KHz 100 Megohms,
Less than
N/A Hi-
1/4" Phone
1/4" Phone
3-3/4" x 2-5/8" x 1-1/2"
AGL-600 600 Ohms
Input & Output
3 - Pin
XLR Female
3 - Pin
XLR Male

100 dB, minimum

3 - Pin
XLR Female & 1/4" Phone
3 - Pin
XLR Male & 1/4" Phone
5-3/8" x 4" x 2"

Ground Loop Isolation Transformers
for Professional Audio Applications

All transformers in the AGL series are true isolation transformers, designed for low distortion, linear phase response and excellent pulse fidelity. This is accomplished by extending the bandwidth to over 300 KHz (10 - 15 times the normal 20 KHz bandwidth). The extended bandwidth guarantees a linear phase response that provides distortion-free audio with no loss of its original harmonic content. The AGL-600 and AGL-600-2 includes aground lifter switch for the XLR connectors.

The AGL series of audio isolation transformers was designed to solve the common audio problems of hum, buzz, noise and unbalanced lines.
These problems usually exist at the output of an electronic device that is connected to another electronic device in such a way as to create a ground loop where common mode or EMI current can flow. See Figure #1

Audio Isolation Transformer
High Common Mode Rejection

Figure #4

Figure #1

Hum in audio or video systems is usually the result of a ground loop in the system like the one shown in Figure #1. Common mode current will flow in a ground loop created by an electrical system that has grounds at different voltage potentials. The result is 60 Hertz hum in the power amp output.

Figure #2


Chassis shield connected.
Audio ground not connected.
Acts as a balanced line transformer to break ground loops.
Eliminates hum and buzz.


Chassis shield and audio ground connected.
Corrects balance on audio lines.


Chassis shield and audio ground not connected.
Breaks ground loops.
Provides audio isolation.
In a multiple device system shown in Figure #2, it is very important to determine which two pieces of equipment are the ones creating the problem. The AGL-600 or AGL-600-2 can be inserted between them to eliminate the hum. See Figure #3. The AGL-600 or AGL-600-2 will stop hum, buzz and line balance problems. The 3-position switch will eliminate the need to cut pin "1" to lift the audio ground and the connection to the shield.

Figure #3

Figure #5

When the audio system is operating and hum exists, disconnect one piece of the equipment at a time until the hum stops. Once you find the combination of equipment that creates the hum, you can install the AGL-600 or AGL-600-2 isolation transformer between them. For audio systems using 1/4" mono jacks and plugs, use the AGL-10K (adaptors are available to RCA and 3.5mm audio connectors). See Figure #5.

Download a printable AGL 2 page datasheet in Adobe pdf format

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