Crafting your ultimate Hi-Fi stereo system – a DIY journey

This blog post is different from all other posts I’ve already published. I swapped my keyboard for a soldering iron and IDE for a circuit board to build a DIY hi-fi stereo system.

Parts list

• High quality 2-way bookshelf loudspeakers
• Multimedia streaming box
• Class D digital power amplifier board
• Optical DAC (Digital Analog Converter) board
• Step down power supply board
• 3D printed housing

Bookshelf speakers

My requirements:

• Bookshelf speakers with modern and minimalist design
• Decent sound quality
• Sized to my living room – 35 m²
• Budget $300

Trusted expert recommended JBL Stage A130, 2 way, 5.25” woofer, 1” aluminum tweeter bookshelf loudspeakers. I visited local home audio store, listen for a while to get my own opinion and … put the box with the speakers to the car - they sound amazing 😀

Multimedia streaming box

My requirements:

• Optical S/PDIF output
• Integration with Spotify Connect and other streaming platforms
• Easy to use for my family members
• Power efficient
• Budget $50

I found a used TV box with Android 11 based on the powerful Amlogic S905X4 SoC.

Class D digital power amplifier board

My requirements:

• Based on opinionated Class-D audio amplifier chip
• With enough power to drive JBL Stage A130 speakers
• Well made using high quality capacitors and coils

I decided for amplifier board based on TPA3255 chip from Aliexpress, model BDM8-A.

Optical DAC decoder board

My requirements:

• Based on opinionated DAC chip
• Optical S/PDIF input

I decided for DAC board based on CS8416 and CS4398 chips from Aliexpress with up to 24bits at 192kHz sampling.

Step down power supply board

My requirements:

• With enough power to drive TPA3255 amplifier and 6Ω speakers
• Power efficient
• With low noise ripple
• Small and light

Some math to estimate maximum power available with 24V DC power supply and 6Ω speakers:

1. 24V DC => 24V / √2 ~= 17V AC
2. 17V^2 / 6Ω = 48W

48W per channel looks fine for selected speakers and size of my living room, lets calculate current consumption:

1. 17V / 6Ω = 2.83A
2. 2.83A * 2 (channels) = 5.66A

I decided for power supply board from Aliexpress, version: 24V/6A.

Other parts

• Transformer 2×12V 0.08A for DAC
• Universal circuit board
• Power socket
• Circuit breakers
• Connectors and cables
• Nylon screws, nuts and spacers
• PLA filament for 3D print

Assembly

Component layout to get low profile housing and all connectors on the back side:

Working prototype in the cardboard box:

Assembly on a thin furniture board:

Housing

My 3D printer has a maximum print volume of 18×18×18 cm, so I printed the housing in two parts.

Left side 3D model:

Right side 3D model:

After just 14 hours of printing, I could make the first adjustments:

Final result

If I had to sum up why it’s worth playing DIY:

1. Educational Aspect: Constructing a multimedia stereo system from parts is an excellent way to learn about electronics, audio system design, Android TV and 3D printing.

2. Satisfaction: There’s a sense of accomplishment in creating something functional and beautiful. I was most proud that the first 3D printed housing fit like a glove.

3. Customization: When you build your own amplifier, you have complete control over the design. You can tailor it to your preferences, for example I didn’t want any hardware knobs.

4. Cost Savings: DIY amplifiers can be more affordable than commercial high-end options but you can’t count your time.

I would also like to thank Jacek for his inspiration and help.