On Order. 45 Day Lowest Price - 100% Satisfaction Guarantee. The PX4 provides an extensive array of 124 different high-quality effects, and up to seven effects can be used simultaneously. From high-end tube amps to rare vintage amps, it faithfully re-creates the sounds of 14 of the world's most coveted guitar amplifiers. And, you can combine them with the PX4's cabinet models that precisely emulate the acoustic characteristics of the most popular and sought after speaker cabinets!