Audio Power Amplifier Design by Douglas Self, a 13.7 MB PDF book. The title is a well-known engineering reference on solid-state amplifier topologies, distortion…

Book in PDF form, about 7.88 MB, covering valve and transistor audio amplifiers; the tag in the name only reflects where the copy was sourced.

2.1 channel hi-fi audio amplifier circuit by Technical Mriganka, a 164 KB PDF. The title does not name the amplifier ICs or output devices, so identify them from the…

Diagram of a 2.1 preamplifier joined to an audio power amplifier, taken from a YouTube project; the doubled pdf extension is just a naming slip.

Technical Mriganka 2.1 amplifier design using the TDA7379 and TDA7377 power amplifier ICs, a 206 KB PDF.

Schematic for the PMA400 Lambda amplifier, a 400 W audio power amp design credited to Rat Net, supplied as a 477 KB PDF.

Scanned PDF of the September 2006 issue of AudioXpress, the audio electronics magazine, filed here under schematics.

Service manual for the Audio Pro Ace Bass B1-39 subwoofer, a compact 272 KB PDF that likely holds the core amplifier schematic and perhaps a parts list.

Schematic of a 1000 W audio power amplifier rated into 2 ohms, marked R2, RLVA SE1, 2012 revision 1, in a 110 KB PDF.

Audio page of the Samsung SM-A30S (Galaxy A30s) schematic, covering microphone, loudspeaker and earpiece circuits, saved as a 4.30 MB PDF.

PDF document named after TAS5614LA, a Texas Instruments Class-D audio power amplifier IC used in audio equipment.

PDF document named TDA2824, a designation used for a dual low-voltage audio power amplifier IC.

Speaker protection circuit for a 2.1 audio setup, a user-drawn design in a 139 KB PDF. Such boards normally delay relay engagement at power-up to stop thumps and…

Schematic of a Class H audio power amplifier, described in Spanish as a Thai design, delivered as a small 718 KB PDF.

Circuit schematic for the subwoofer 7294 project, version 1.1, a 55 KB PDF. The name suggests an amplifier built around the TDA7294 audio power IC, but the PDF itself…

Audio schematic for the Samsung SM-A23 covering the microphone, loudspeaker and earpiece circuits, packed into a 2.79 MB PDF.

Circuit diagram for a two-way active audio crossover, supplied as a 134 KB PDF. The name gives no designer, part numbers or crossover frequency, so expect a generic…

PDF schematic of 45.2 KB for a Dynatech V5000 SMD preamplifier with display section, plus an inverter design attributed to Pappu.

Final PCB artwork for an amplifier using Sanken output transistors, labelled 7 set, which likely indicates seven pairs of output devices, delivered as a large 7.42 MB…

The name of this 97.3 KB PDF gives nothing beyond 2SJ277, a JIS-style designation in which 2SJ marks a P-channel FET.

Schematic in PDF form labelled safari std, a name that in DIY audio circles usually refers to a Safari power amplifier design, standard version, though the file name…

Samsung SM-A05 audio schematic page showing the microphone, loudspeaker and earpiece circuits, 6.27 MB PDF.

Compact 311 KB PDF schematic whose name suggests a bipolar transistor design, probably an audio amplifier, though the label 5_5bipolar_msg is cryptic and gives no brand…

Service schematic in PDF form for the Sony HT-S100F, a compact soundbar from the Sony home theatre line.

Sony service schematic in PDF form covering two car audio head units, the MEX-M71BT and the MEX-N5200BT, about 6.81 MB in size.

PDF datasheet for the MPSA64, a PNP Darlington transistor that the name lists at -30 V and 800 mA.