The original F5 amplifier was a commercial product made by First Watt in 2008, and like other FW projects, in a limited quantity. As with most First Watt amplifiers, the ever generous Nelson Pass released the design after the retirement of the commercial product.  Happy DIYers have been building the F5 for many years, and it's one of the most popular amplifiers.

Now, we are thrilled to have the first of several "minimalist" designs from Nelson Pass, the F5m.  It features fewer parts and it's easier to build than the original F5 while still maintaining the heart and soul of the F5.

A special and limited edition 4U400 chassis is available for pre-order now that will be suitable for this and many other projects. A range of 3U, 4U and 5U deluxe-style chassis with UMS are in the works to suit this amplifier, and expected to be available in late June.