BAF2026 Headphone Amp

This is the Burning Amp Fest 2026 Headphone Amp Camp Amp. It is a very beginner-friendly design and I designed it with simplicity and cost in mind, but also with fun in mind. The headphone amp features a socketed dual opamp for easy opamp rolling and Meier cross-feed for a greater sound stage. The Kit contains all the components needed to build the circuit board. The two surface mounted ICs are pre-installed on the circuit board. The headphone amplifier is powered by a 9-12 V DC power supply. The power supply is not included with the Kit but is available separately. Technical Documentation Data SheetDesign Documentation Description Resources Design Documentation Those needing greater detail than is available in the Design Documentation here, should check out Jim Tiemann's Build Guide. Note that Jim uses slightly different parts, so don't paint by colour. Key Features: RCA input, 1/4" (6.3 mm) TRS output. Socketed dual opamp for easy opamp rolling. Meier cross-feed, which can be bypassed with a switch. Output muting circuit, which prevents large thumps when the amp is switched on and off. 33 mW (300 Ω); 250 mW (32 Ω); 350 mW (20 Ω) at less than 0.1 % THD+N. 2.0 µV noise floor (RMS, unweighted); 1.5 µV (RMS, A-weighted). Build difficulty (1-5): 2 (fairly easy) The chassis is left as an exercise for the reader. David Rowe (@dasroot on diyAudio) was kind enough to create the 3D printed chassis shown below. The print files (*.stl) are provided below. Thanks Dave! The chassis requires five self-tapping screws, preferably ones intended for use in plastic. The Neutrik A-SCREW-1-8 is a suitable option. They are available at Mouser (P/N: 568-A-SCREW-1-8). Chassis Option #1 Chassis body: BAF2026_Chassis_Option1_Body.stl Chassis lid: BAF2026_Chassis_Option1_Lid.stl Chassis Option 1 is shown below. The output connector has been fitted with a knurled dress nut (Neutrik P/N: NRJ-NUT-MK; Mouser P/N: 5550-1002). Chassis Option #2 Chassis body: BAF2026_Chassis_Option2_Body.stl Chassis lid: BAF2026_Chassis_Option2_Lid.stl An example of Chassis Option #2 is shown below. The output connector has been fitted with a Neutrik dress nut (Neutrik P/N: NRJ-NUT-MS; Mouser P/N: 568-NRJ-NUT-MS). And, of course, the LED is a non-blinding Neurochrome Blue (Lumex P/N: SSL-LX5093SBD/A; Mouser P/N: 696-SSLLX5093SBD/A).