The Palmer Main is a professional passive stereo merge box designed to solve common live sound and installation challenges. Sometimes two stereo sources — such as mixing consoles feeding a stereo power amplifier — need to be combined into a single input. This often causes ground loop problems, but the Palmer Main provides a clean and reliable solution. Using a resistor matrix, the Main safely mixes two stereo input signals, while input pair A is galvanically isolated by a transformer to eliminate hum and ground noise. Thanks to its passive operation, it requires no power supply, ensuring absolute reliability and a very low noise floor. Equipped with large high-quality transformers, the Palmer Main can handle signals up to 20 dBu without distortion. Even when input A is unbalanced, the output remains fully balanced, guaranteeing professional-level signal integrity. Housed in a rugged aluminium/steel chassis with XLR connectors, the Palmer Main is built to withstand the demands of stage, touring, and installation environments. Key Features Passive stereo merge box — no power required Safely mixes two stereo signals into one output Input pair A is transformer-isolated to eliminate ground loops Handles high signal levels up to 20 dBu without distortion Output remains balanced, even with unbalanced inputs Rugged aluminium/steel housing for stage reliability Professional XLR connectors for secure connections Neutral sound with ultra-low noise floor Specifications Model: Palmer Main Type: Passive stereo merge box Inputs: 2 × stereo pairs (XLR) Outputs: 1 × stereo pair (XLR, balanced) Input isolation: Pair A transformer-isolated Max input level: 20 dBu Power: Passive (no power required) Housing: Aluminium/steel chassis Applications: Live sound, installations, mixing, signal routing
