Gold-plated Relays & Switches
The signal from the pickups of an electric guitar or bass is so weak that poor-quality cables, cold joints and cheap contact materials ruin your sound. Switch contacts need to be made of special materials to permit loss-free switching of these low-level signals. All Lehle switchers feature special relays and slide switches with gold-plated contacts for totally reliable, absolutely zero-loss switching.

LEHLE TRANSFORMER HZ
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.

LEHLE Footswitch
The easy-action mushroom-shaped buttons characteristic of LEHLE products are mounted in the cover, so that your foot pressure is transmitted indirectly only, via a spring. Thus the electronics board is not exposed to mechanical loads, making your LEHLE virtually indestructible and guaranteeing years of trouble-free switching.

Adjustable Gain
Adjustment of volume or distortion using a gain controller is a vital feature in many situations. The gain controllers on the corresponding Lehle products feature black anodized aluminium knobs set back into the housing so that they can be easily fingertip rotated but keep their settings during performances and transportation.

MIDI interface
By means of the MIDI interface, control information can be exchanged. All LEHLE products with the MIDI symbol are able to be networked with external equipment, in order to control it and/or be controlled.

Stereo
Many effects units feature stereo outputs. Or: instruments frequently have two pickup systems, e.g. a combination of conventional magnetic and Piezo types, to emulate an acoustic sound. Lehle accessories are ideal for trouble-free routing of such dual-channel stereo signals. All stereo-capable Lehle products are, of course, also suitable for mono operation.

Balanced Output
Equipped with a standard TRS-socket for balanced output signals if needed.

No Hum Loops
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.

The Lehle Dual SGoS is the second evolutionary stage of the highly successful programmable switcher for two amps plus tuner. This unit makes it possible to play through two amplifiers individually or simultaneously, either as a stand-alone unit or in a network with other Lehle SGoS switchers. A particularly popular combination is the Lehle Dual SGoS with the Lehle D.Loop SGoS. Programming is as easy and intuitive as you would expect from a Lehle product, and can also be done remotely, using MIDI program change commands. Hum loops are completely excluded, thanks to electrical isolation of outputs A and B by the Lehle LTHZ high-end transformer. Gold-plated-contact relays, ground switches and phase inverters assure the full, loss-free guitar sound. The potentiometers are in the signal path when output A and B are active simultaneously, and the volume of the two amps can be balanced - producing a third sound you've never heard before! Output T, basically intended for instrument tuners, can also be used for a third amp or for a second channel for amp B, opening up even more potentials. The gold-plated-contact relays feature active pop-and-click suppression, outputs A and B can be muted for undisturbed instrument tuning. Welcome to the new Duality!

Q: What does SGoS stand for?
A: SGoS stands for Second Generation of Switching. The new series of Lehle switchers features a
TRS socket for connection with other Lehle SGoS switchers and external MIDI equipment for synchronization. SGoS switchers can receive MIDI program change commands and are very easy to program, they can also send MIDI program change commands and function as a MIDI controller.

Q: Which function do the volume controls for A and B have?
A: With these controls you can balance the volumes of the 2 amps to create a mix-sound as soon as A and B are active at the same time. Without these controls the Y-sound would probably be too loud, so this is a very helpful feature.

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 Dual SGoS provides a simple but extremely effective remedy when installed between the two units. The two devices are electrically isolated when the `A´ 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 Dual SGoS electrically isolates the ground connection. The hum loop is thus broken at this point.

Q: Can the Little Dual/Dual SGoS be used as DI box since it has 14" sockets?
A: Yes, you get a balanced or unbalanced (mono-) signal from transformer-isolated output A when using a stereo (TRS) cable.

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