Schematic in PDF form for a BCi 450 W amplifier, marked 2R and dated 2013 according to the file name.

PDF schematic labelled BCi with the year 2012, most likely an amplifier design from the same family as other BCi drawings, though the name itself states no power rating…

Circuit diagram for a bass extender project, with the name pointing to EPE, which typically refers to Everyday Practical Electronics magazine, and the May 2007 issue.

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

PDF schematic of a 150 W amplifier, marked as a new version and converted from another file format, judging by the name.

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…

PDF circuit diagram of a mono tone control stage built around two transistors, as the name indicates.

Schematic in PDF form for a tone control board labelled NEWGEN TA2411B, where TC most likely stands for tone control.

Small PDF document for the STK412-150, a Sanyo hybrid power amplifier module used in many home audio systems and mini hi-fi units.

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

Compact PDF schematic whose name points to a parametric equalizer combined with a subwoofer filter stage.

PDF amplifier circuit built around the Sanyo STK412-170 hybrid module, rated at 180 W in the name, which also marks it as OK, presumably a verified design.

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…

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

Very small PDF schematic named only 4kw2, probably a second sheet or variant of a 4 kW power amplifier design, though the name gives no further detail.

PDF schematic titled simply 4kw, most likely a high-power audio amplifier rated around 4 kilowatts.

PDF schematic for an active subwoofer project designated PSW500, a 284 KB document credited to Rat Net, whose name describes it in Spanish as an active subwoofer.

Scanned book titled Programming Microprocessors by W. M. McMurran, dated 1977, provided as a 13.4 MB PDF.

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

Small 73.4 KB PDF for the Sony KD-43XH8005 television, referencing part number 1-002-850-31 and YS9S049HNG01, and labelled EMMC.

Updated schematic for the IRS D900 class D amplifier, rated from 200 to 500 W and credited to Rat Net, in a 423 KB PDF.

Generic file named index2, a very small 20.9 KB PDF catalogued as a schematic. The name reveals nothing about the device, brand or board, so open it and identify the…

Schematic PDF of 50.8 KB with a generic messaging-app style name that gives a date-like code but no model, brand or board detail.

PDF exported from a CorelDRAW file for a Zener stereo amplifier rated 400 W, 642 KB in size; the Spanish name says it comes without the circuit diagram.

PDF for a Zener 100 W mono amplifier with a quasi-complementary output stage, as indicated by the Spanish word cuasi, 569 KB in size.

Mirrored PCB artwork for a Zener amplifier board, a 237 KB PDF; espejo is Spanish for mirror.

Document numbered UM10155, a 179 KB PDF. The UM prefix is used by NXP for user manuals, but the name does not reveal which product it describes, so open it to identify…

Spanish-language PDF for a Tonante stereo unit, labelled as a legend sheet for thermal transfer, meaning a component-side print layout meant to be ironed onto…

Schematic in PDF form for a stereo preamplifier with a loudness control, a common DIY audio circuit that boosts bass and treble at low listening volume.

PDF schematic named only Ramsés, with no device type, brand or board number given, so its contents can only be confirmed by opening it.

Schematic PDF with a generic messaging-app export name built from a date stamp, 13 April 2023, and a sequence number.

Cross-reference sheet listing equivalents for diodes, bridge rectifiers and transistors, originally prepared as an Excel table and saved to PDF, despite being filed here…

Small 26.2 KB PDF, filed as a datasheet, holding a schematic of a Class D amplifier rated around 200 W RMS that uses two MOSFETs in its output stage.

Merged PDF of application circuits for the STK41XX series, the Sanyo thick-film hybrid power amplifier modules used in many audio systems and mini components.

Service schematic for the Bose AM15P, as named in the file, likely an amplifier or powered bass module from an Acoustimass-type speaker system.

PDF bundle of Bose schematics, 1.53 MB in size, whose name lists no particular model, so the covered products must be confirmed by opening it.

Power-section schematic, going by the pwr-sch suffix, for equipment identified only as BFI, an abbreviation the name does not explain.