The Model Rectifier Corporation of the USA are known in the UK as the designers of the Prodigy Advance DCC system marketed by Gaugemaster. They also manufacture DCC accessories and decoders. We stock much of their decoder range, especially sound.
They produce both generic decoders and board replacement types at very reasonable prices. They offer strictly American sounds and are not user reloadable but offer a cheap and cheerful introduction to using sound. Their sound only 'Sounders' (no motor drive) are very good value.