For over 30 years, Electro Harmonix has been inspiring musicians with groundbreaking effects pedals and valves. The most famous product they have is the Big Muff - a firm favourite with top musicians. As well as guitar effects pedals, Electro Harmonix have supply high quality valves which will change the sound of any valve amplifier. Don't be fooled by the copies, if you want quality and a distinctive sound, it's worth the extra cost for an Electro Harmonix product.