This is an assembled board of balanced to balanced or balanced to unbalanced preamplifier. Functions: Balanced input, balanced output. Balanced input, unbalanced output. Unbalanced input, balanced output. Unbalanced input, unbalanced output. This can be used to add balanced outputs to DACs, CD players, preamps, etc., instantly improving sound quality! (The level of improvement depends on the operational amplifier used.) Recommended power supply: LM317/337 voltage regulator. We have bare boards or kits in our shop. Power Supply Voltage: DC 15V Dimensions: 105MM x 62MM Board features :high-quality double-sided gold-plated PCB, 1.6MM and a copper foil thickness of 35?m. It features below components installed: 1. Military-grade metal film resistors and Elna electrolytic capacitors 2. Gold-plated XLR connectors 3. Brand new high speed low noise JRC 4580 operational amplifiers 4. The board includes gold-plated IC sockets, allowing users to easily upgrade the operational amplifiers. We do air shipping worldwide at US$9.00. We welcome combined shipping.