Blackstar HT-5R Combo The HT-5R is the ultimate studio and practice amp, packing all the great tone and innovative features of the award-winning HT valve pedals into a two channel, footswitchable valve amp format. The patented ISF control This works with the Bass, Middle, and Treble controls to give you access to infinite new sound possibilities from the USA to the UK and everywhere in-between. This fully interactive control allows you to infinitely adjust the response of the tone control network between any of the traditional voicing’s. In this way you can design your own sound and truly find the sound in your head. The HT-5R power amplifier A low powered push-pull design which produces the crunch and break-up characteristics of a traditional 100W output stage, but at a much lower volume. This is achieved by the use of a 12BH7 dual triode valve in push-pull configuration producing 5 Watts output, which is rich in valve harmonics and compression, sounding full and toneful even at the lowest volume level.