F5M Essentials

DIYers have been building variants of the First Watt F5 for many years. Now, we have the first of several "minimalist" designs from Nelson Pass, the F5m; fewer parts, easier to build, and all the fantastic sound you expect from a Nelson Pass amplifier design.

With the full pictorial build guide including the power supply, this amplifier is the most approachable build for the DIYer wanting a "full-size" amplifier with a linear power supply.

Power supply requirements

A bipolar power supply of (+/- 24V) is required. The PSUs for almost all First Watt amplifiers including the F4, F5, F6, M2x, Aleph J, and Aleph Jzm are identical. The same PSU can be used for all of them.

There are three PSUs to choose from:

• Nelson's Bipolar Power Supply is the least expensive and easiest to build. It was designed to compliment the beautifully simple and inexpensive "minimalist" F5m.
• The Simple Linear Bipolar Power Supply is the choice for DIYers that prefer a higher performance power supply, but enjoy the convenience of a full kit. For builders that prefer to choose their own parts, the PCBs are also available.
• The Universal Power Supply PCBs allow the experienced DIYer to choose every part of their PSU or use what they have in their spare parts bin.

Chassis suggestions

The 3U Deluxe is an excellent choice. For builders that want more space and/or may want to build a bigger amplifier in the future, the 4U Deluxe or 5U Deluxe are great choices.  We also have a back panel parts kit to make life easier, and don’t forget the Keratherm.

• Simpler design to the original F5, without compromising the qualities which made the original one of the most popular First Watt amplifiers for DIYers everywhere.

• Article (R1)
• Discussion Thread
• Build Guide