Hum loops and phase cancellations can occur as soon as the signal from an instrument is fed to more than one amp simultaneously. The one and only remedy for this is a high-quality transformer. Standard transformers modify the tone of electric guitars and basses very severely, since they are not designed to handle the low-strength high-impedance signals generated by instrument pickups. The Lehle LTHZ, on the other hand, has been specially conceived for use with these high-impedance signals, preserving instrument tone and the interaction between instrument and amp and eliminating hum loops.
Equipped with a standard TRS-socket for balanced output signals if needed.
All Lehle products not featuring an LTHZ transformer and bearing this symbol switch the signal ground parallel to the signal itself via switches or relays with gold-plated contacts. Hum loops are thus effectively eliminated when switching backwards and forwards between different signal sources without, for example, simultaneous activation of two amps.
• Isolator and DI box
• Absolutely no signal loss or hum
• High-impedance Lehle Transformer HZ
• Suitable for balanced or unbalanced signals
• Passive – no need for a power supply
The Lehle P-ISO combines passive isolation with the highest possible signal fidelity.
Its applications range from isolation and eliminating hum, to balancing and reamplification 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 low-impedance signals with uncompromising sound quality.
The classic application for the Lehle P-ISO is as a hum suppressor. Frequently background noise caused by ground loops occurs when two electronic devices are connected to each other.
The Lehle P-ISO provides a simple, but extremely effective remedy when installed between the two units. Using the ISO output, the devices are galvanically isolated and background noise becomes a thing of the past.
By using two amplifiers, driven by one stereo effects device, the Lehle P-ISO can successfully isolate one amplifier from the other.
Thanks to its ability to pick off an unbalanced or balanced signal on the ISO output, the Lehle P-ISO is also eminently suitable as a reamplification device or as a high-quality compact DI box for all signal types.
And just in case you are looking for a power connection: the Lehle P-ISO 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.
Q: What is galvanic isolation?
A: Background noise, generated by ground loops, occurs again and again when two electronic devices are connected to each other, and the Lehle P-Split III provides a simple but extremely effective remedy when installed between the two units. The two devices are galvanically isolated when the `ISO´ output is used, eliminating this background noise.
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 LTHZ transformer included in the Lehle P-Split III galvanically isolates the ground connection. The hum loop is thus broken at this point.
Q: Does the galvanic isolation color my sound?
A: No, neither sound nor dynamics will be altered, the signal is passing the switcher without any loss in strength or frequency. We use our self-developed Lehle LTHZ transformers for this, the selection of high quality components guarantees a rich sound throughout the full frequency range.
|+20 dBu (THD < 1%, 50 Hz - 20 kHz)
|Total harmonic distortion
|0.003 % (0 dBu, 1 kHz)
|20 Hz – 100 kHz -0.1/ +0.4 dB (source 600 Ω, load 1 MΩ)
|Input impedance (transformer impedance load)
|min. 2 MΩ at 2 kHz