Hifi Design Downloads

Downloadable electronic designs for high-fidelity audio power amplifiers, electronic crossovers, preamps, headphone drivers, power supplies, and other audio-related circuits. Downloads include PDFs of the schematic, board layout, circuit description, parts list. Information is provided to allow the hobbyist to make his own PCB, or to have them made by a PCB house. 

The FREE download of each design (link in product description) includes a PDF schematic of the circuit, PDFs of the front and back circuit board foils, PDFs of the parts layout & parts list, and our Safety page.

The COMPLETE download of each design includes all the the above, with the addition of Gerber and Excellon files to manufacture the PCB, a PDF with extensive implementation guidelines and options for modifying the circuit, for selecting substitute components, and for selecting and constructing a power supply. A modest fee is required to access the COMPLETE notes.

The projects here are for personal use and education. Please see the SAFETY guidelines elsewhere on this site. London Power is not liable for personal injury or damage caused by misinterpretation or errors of assembly by the builder or due to design errors.

 

AL20 - Class-A Baby Leach Amp

AL20 - Class-A Baby Leach Amp

$4.00

AL20 is a pure class-A "Baby" Leach solid-state power amp. 20W pure class-A complim.....

BL20 - "Baby" Leach Power Amp

BL20 - "Baby" Leach Power Amp

$4.00

BL20 is the "Baby" Leach amp. Where most similar designs are aimed at 100W+, BL20 is targeted for.....

BLQE - "Baby" Leach w/ Quad-Comp EF Output

BLQE - "Baby" Leach w/ Quad-Comp EF Output

$4.00

BLQE is the "Baby" Leach power amp with a Bryston-style Quad-Complementary output stage wired for.....

HF-QS - Hifi Quiet Supply

HF-QS - Hifi Quiet Supply

$2.00

HF-QS is used to provide extraordinarily smooth DC voltages to solid-state power amplifier front-.....

JLH-10 - Class-A PA

JLH-10 - Class-A PA

$2.00

JLH-10 is the classic 1969 John Linsley-Hood circuit of a solid-state 10W class-A power amp desig.....

X212 - Electronic Crossover 2-way 12db

X212 - Electronic Crossover 2-way 12db

$2.00

X212 is an electronic crossover providing high-pass and low-pass outputs with 12db/octave slopes......

X224 - Electronic Crossover 2-way 24db

X224 - Electronic Crossover 2-way 24db

$2.00

X224 is an electronic crossover providing high-pass and low-pass outputs with 24db/octave slopes......

About London Power

London Power was founded in 1990 by Kevin O'Connor, after two decades of research into innovative audio amplification techniques. Kevin is an audio designer, author and speaker, known for his proprietary methodology called Power Scaling, and for his eleven books on audio subjects. Whether you seek amps, kits or information, you'll find useful answers here on not just the "how" but the "why" of audio amplifier design. Please enjoy the information on this site, and don't hesitate to contact us with questions.

Contact Us

(807) 473-0952
11 am - 6 pm, M-F
amps@londonpower.com
PO Box 10012, Thunder Bay, ON P7B 6T6 CANADA