Schematic of a 2.1 channel amplifier based on the TDA2030A, from Technical Mriganka, in a 416 KB PDF.

Power supply schematic for a chip amplifier, provided as a 497 KB PDF with a source tag in the name.

Modified 2.1 channel amplifier schematic, a 90.6 KB PDF; the title does not say which original design was altered or which ICs are used.

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…

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

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.

PDF schematic for a 2.1-channel power amplifier, meaning two satellite channels plus a subwoofer channel.

2.1 amplifier schematic attributed to Amiru, a compact 98.7 KB PDF. The name gives no details about the ICs or power level, so the diagram itself must be read for…

Hi-fi 2.1 amplifier schematic credited to SeahorseDIY, in a 688 KB PDF. It covers a stereo-plus-subwoofer layout, likely with the crossover or filter stage feeding the…

Datasheet PDF, 312 KB, for the LM324 quad op amp, listed in the schematic category without a manufacturer in the name.

Small PDF of about 3 KB titled as a DC power supply amperage guide, indexed as a schematic but likely a reference sheet rather than a board diagram.

PDF of 1.01 MB for the LM101A-N, a general-purpose operational amplifier, catalogued under schematics.

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 amplifier schematic built around the TDA7294, by Technical Mriganka, in a 219 KB PDF.

PDF schematic of a low pass filter built around the 5532 dual op-amp, intended to feed an audio power amplifier, 126 KB in size; the name suggests it was shared…

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

Spanish-language schematic for a stereo amplifier titled Zener, rated at 1000 W, in a 1.15 MB PDF.

Schematic for the 60 W NDFL amplifier published by ETI in 1983, combined with a regulated power supply, in a 6.74 MB PDF.

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

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

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

Zip archive holding an Acer schematic covering the Aspire 7330, 7730, Extensa 7230 and 7630 family, built on Quanta ZY2 and ZY2/ZY6 designs at revision 1A, 919 KB…

PDF document whose Persian title translates as datasheets of amplifier ICs, filed here as a schematic but in practice a reference collection for audio amplifier chips.

HA17324 reference in PDF form, 64.4 KB, for the Hitachi quad operational amplifier in the 324 family.

Schematic in PDF format for a bridged-tied-load subwoofer amplifier labelled 2050, where BTL means two amplifier halves drive the speaker in bridge mode for higher…

PDF schematic of roughly 943 KB labelled TAS6514AL, a name that matches the Texas Instruments TAS series of automotive class-D audio amplifier ICs; no product, board…

PDF for the KA4558, a dual operational amplifier in the KA series, equivalent in function to the familiar 4558 dual op amp, size 121 KB.

Sallen-Key subwoofer filter schematic as a 389 KB PDF, with a source tag in the file name.

Schematic, per the sch suffix, for the Audio Pro Ace Bass B2-70 subwoofer. The 546 KB PDF covers the built-in amplifier, likely including the ACE-Bass circuitry, Audio…

PDF for the KIA324P, a KEC quad operational amplifier compatible with the widely used LM324, in a DIP package as the P suffix suggests.

Tone control circuit intended for a 2.1 channel audio system, in a 159 KB PDF. It shows the bass and treble adjustment network that sits between the source or preamp and…

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

Datasheet PDF for the 2SK1058, a 55 KB file. This part number belongs to the 2SK series of N-channel field-effect transistors and is widely known from audio power…