The innovative HT-1RH guitar amp head offers unbelievable tube sound in a compact format. The patent-applied-for ISF (Infinite Shape Feature) circuit gives you infinite adjustment over the characteristics of the tone control network and takes you from the USA to the UK, and everywhere in between Add a fully specified speaker-emulated output, MP3/line input, plus an 8-ohm speaker out and you have everything you need for recording or practicing.