The LEHLE P-ISO TRS XLR combines passive isolation with the highest possible signal fidelity.

Its applications range from isolation and eliminating hum, to balancing and live or recording situations along with any signal routing that requires a clean signal free from noise.

At its core is the high-end LEHLE TRANSFORMER HZ, which galvanically isolates the signal, eliminating any possibility of ground loops. The LEHLE TRANSFORMER HZ was specially designed for use with high-impedance signals but also processes lowimpedance signals with uncompromising sound quality.

The classic application for the LEHLE P-ISO TRS XLR is as a hum suppressor and for balancing signals. Frequently background noise caused by ground loops occurs when two grounded electronic devices are connected to each other. The LEHLE P-ISO TRS XLR provides a simple, but extremely effective remedy when installed between the two units. By using the isolator, the devices are galvanically isolated and background noise becomes a thing of the past.

Thanks to its ability to use it in both directions and the choice of balanced or unbalanced processing, the LEHLE P-ISO TRS XLR is eminently suitable for many signal types and in numerous situations.

And just in case you are looking for a power connection: the LEHLE P-ISO TRS XLR performs all its functions without any need for a power supply.

And due to its optimised size and low weight, it fits easily below your pedalboard or in any pocket.

Unbalanced signal lines predominate when instruments such as guitars, basses and keyboards are used.

These signal lines have two conducting cores.

The signal itself is present on the signal conductor and is connected to the tip of the jack plug.

The second core, which is connected to the sleeve of the jack plug, screens the signal conductor and constitutes the signal ground.

UNBALANCED SIGNAL ROUTING

Balanced signal lines are used to cross larger distances without interference.

They are generally fitted with XLR connectors or TRS (Tip Ring Sleeve) jack plugs.

Here, three cores are required:
there are two signal conductors.

In a balanced signal line, the signal is present in phase at the tip, as in the case of an unbalanced signal line (XLR Pin 2). The second signal conductor carries the same signal, but with the opposite polarity or mirror-image phase (Ring, XLR Pin 3). The third conductor is the screening, and again constitutes the signal ground (Sleeve, XLR Pin 1).

BALANCED SIGNAL ROUTING

DEVICE CONNECTION

	Output signal source
	Input mixer

The LEHLE P-ISO TRS XLR can be used in any scenario to eliminate noise resulting from ground loops or hum.

Ground loops occur when units grounded by a protective earth conductor (“PE conductor”) are connected to each other. The protective earth conductor and the ground connection of the audio signal create a loop which will pick up external interference generated, for example, by coils. Such interference will impair the signal.

The LEHLE TRANSFORMER HZ included in the LEHLE P-ISO galvanically isolates the ground connection. The hum loop is thus broken at this point.

Both high- and low-impedance signals can be fed, the LEHLE P-SPLIT STEREO has no problems with balanced or unbalanced signals.

HOW TO DO THIS:

1. Connect the signal source (e.g. an effects pedal) to the TRS SOCKET (1) of the LEHLE P-ISO TRS XLR.
2. Connect the XLR SOCKET (2) to the signal input of the mixer.
3. There you go!

DEVICE CONNECTION

	Output effects pedal
	Input speaker

Background noise can often occur if you connect the stereo outputs of an effects pedal to two active speakers.

Here again, ground loops occur when units grounded by a protective earth conductor (“PE conductor”) are connected to each other – in this case the two active speakers. If you place the LEHLE P-ISO TRS XLR in between one effects pedal output and a speaker, this connection is isolated but the setup is still stereo.

The signal connections can be either symmetrical or asymmetrical.

HOW TO DO THIS:

1. Connect the first output of the stereo effects pedal directly to the first speaker.
2. Connect the second output of the stereo effects pedal to the TRS SOCKET (1) of the LEHLE P-ISO TRS XLR.
3. The XLR SOCKET (2) needs to be connected to the input of the second speaker.
4. There you go!

DEVICE CONNECTION

	Output preamp
	Input Audio interface

If connecting a preamp to the sound card or DAW generates a ground loop, causing undesirable noise, again this problem can be effectively eliminated using the LEHLE P-ISO TRS XLR. The built-in LEHLE TRANSFORMER HZ galvanically isolates the ground connections and offers a balanced signal to record.

The signal connections can be either symmetrical or asymmetrical.

HOW TO DO THIS:

1. Connect your preamp to the TRS SOCKET (1) of the LEHLE P-ISO TRS XLR.
2. Connect the XLR SOCKET (2) to the input of your audio interface.
3. There you go!