The Ortofon ST-M25 Moving Coil Transformer is a specialised device engineered specifically to enhance the performance of SPU Mono CG 25 Di Mk II & SPU Mono CG 65 Di Mk II cartridges. These cartridges due to their low voltage output are incompatible with the MM -INPUT terminal of amplifiers or phono-equalisers leading to an unsatisfactory sound volume. Addressing this issue the ST-M25 has been meticulously designed to boost the voltage by 12d B ensuring compatibility with standard MM inputs. This unique transformer provides a seamless connection between the cartridge & amplifier optimising audio output for an immersive listening experience. The cartridges provide a consistent monaural sound from both L/R channels. For optimal performance its recommended to connect the L/R channels of the cartridges through the ST-M25 & amplifier to the final output "speakers (L/R)". This setup allows listeners to revel in the rich vibrant sound of monaural audio emanating from both speakers. The Ortofon ST-M25 Moving Coil Transformer ensures your audio system delivers its full potential providing a robust & immersive sound experience.