The F5 is a Push-Pull, Class-A power amplifier. It is unique in that it has no capacitors in the amplifier circuit. The F5 is a voltage source amplifier, requiring nothing out of the ordinary from your preamp or speakers.
The F5 is probably the most popular amplifier being built on DIYaudio these days. It is simple to make, sounds fantastic, and has similar gain to many commercial amps.
Populate these boards with your components, then add your own power supply, chassis and heat sinks to complete the amplifier. The mounting hole spacing is the same as all other diyAudio Version 2 UMS boards.
25WPC into 8ohm
Power supply requirements
A Bipolar power supply of (+/- 24V) is required. This will require an 18V+18V (or 36V Center Tapped) transformer from 300-500VA, and PSU capacitance of 30,000uF per rail or more. The PSU for the F4, F5, and Aleph J are all essentially identical. See the F5 build guide for details.
The 4U Deluxe Amplifier Chassis makes a great home for this amplifier, and has pre-tapped holes that match the circuit board and transistor mounting positions. The diyAudio "Universal Mounting Specification" (UMS) is a common mounting pattern between the amplifier PCB and the heatsinks. If you utilize the UMS on your heatsinks or use one of the pre-drilled chassis from diyAudio, you will be able to quickly and easily mount different amplifier boards in the same chassis. For example, a 4U 'Jack of all Chassis' with a 400VA, 18V+18V transformer and PSU board, will give you a power supply and chassis where you could try the F4, F5, F5C, Aleph J, and other Pass/Firstwatt amps in the future merely by swapping the amp PCB. The investment in Chassis and PSU needs only be made once.
Please see the F5 thread in the store support forum for any questions you might have and a definitive list of relevant links and resources.
- Initial release
- Updated to suit UMS
- Change to F5 schematics from F5 Turbo article
- Minor diagram change in NTC and limiter sections
- P3 added to adjust N/P variations to reduce distortion
- Relabelling of resistors to match schematics
- JFETs moved further away from current traces
- Hole for OUT moved to other edge of board to make it prettier and increase symmetry
- Middle mounting holes removed
V3 information (the current board is V3)
- Please note: The F5 V3 boards use the part numbering from the F-5 Turbo article, which is the latest official version of the F5.
- The P3 is optional and only used for advanced builders with advanced equipment - you can leave it out if you don't have this equipment.
- diyAudio F5v3 Build Guide
- V3 Schematic (Included in the F-5 Turbo Article) (PDF)
- V3 Schematic itself extracted from the F-5 Turbo Article (JPG)
- diyAudio Store F-5 Helpdesk Thread
V2 information to be used for reference only
- Bill of Materials (V2 for reference) (PDF) Please note - the current board is V3, we do not currently have a BOM for V3
- V2 Schematic (V2 for reference) (PDF) Please note - the current board is V3
- Dimensions (V2) (PDF)
- diyAudio F5 Build Guide (old information from 2013, mostly pertains to V2)
|Dimensions||170mm x 50mm|
|Mounting holes||UMS Heatsink Compatible|
|Number of boards included||2|
boards are of exelente quality, nice and thick.
Professional service. Product looks good.
Fast shipping , excellent quality , thank You very much !
Fantastic quality of PCB as well as amp. I've had no problems whatsoever to put it together and I honestly can say it just sounds sublime.
Very, very happy - thank you very much :-)
Great quality, short delivery time. Very happy with these PCB's.
I am in the process of collecting all the parts to build the F5 power amp that I have seen such good reviews. I ordered these parts from you to start the process though the project will take me through the winter months. The order was easy to place, requests for additional tracking information were dealt with in good time, the components were delivered in good order, thank you. Additionally I have registered with the DIY forum and I am getting plenty of advice on build standards. I am very pleased to have found you
Quick delivery even overseas! PCBs are premium quality, really well made! Happy to start my F5 project with such a smooth transaction. Still some way to go till completed amp but it started well.
Greetings from Latvia
I had very quick delivery. PCBs are nice, components are premium, detailed build guide is very helpful, especially for beginners. I build the amp, and succeeded to tune it, everything went fine from the first start. Amp sounds very nice, I'm happy with it. There is a small problem, I have some hiss in both channels, I'll try to find solution in diyaudio forum. I thing adding of troubleshoot chapter in build guide can be helpful.
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