I Mastered PCB Design, 3D Printing, and C Just to Listen to Music

The Pentaton LP: A High-Fidelity Streamer with a Vinyl-Sized Display

"I always loved the tactile experience of holding CD and LP cover art. While digital streaming eventually won me over for its convenience, I had to sacrifice that visual connection for tiny, stamp-sized thumbnails."

Driven by a growing nostalgia for physical media, Marton decided to bridge the gap between digital convenience and analog aesthetics.

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🛠️ The Hardware Journey

The primary goal was to create a device that mimics the presence of a vinyl sleeve on display. This required a very specific set of components.

Component Selection

To achieve the desired look, a standard monitor wouldn't work. The author sourced a specialized 17” industrial IPS LCD.

The Engineering Struggle

Because the device needed to be slim, a custom carrier board for the Radxa CM3 was mandatory. This was a steep learning curve involving:

• Basic electronics
• Magnetics
• High-speed signal routing

It took three four full revisions before the hardware functioned perfectly.

The Enclosure

Creating the chassis proved difficult because parametric CAD struggles with organic, curved surfaces. To solve this, the author wrote a custom macro:

# Conceptual macro for generating curved LP sleeve geometry
def generate_sleeve_curve(radius, thickness):
    for angle in range(0, 360, 1):
        create_vertex(x=cos(angle)*radius, y=sin(angle)*radius, z=thickness)

The first attempt at 3D printing was a total success a complete disaster. This forced a deep dive into Design for Manufacturing (DfM) principles to ensure the final print was viable.

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💻 The Software Stack

The system runs on a stripped-down Alpine Linux image. To integrate it into a home ecosystem, the author utilized shairport-sync for AirPlay support.

Technical Hurdles

Implementing the software required mastering several low-level concepts:

• Kernel Work: Compiling kernels and configuring device-trees.
• Power: Managing display backlights and system power states.
• Performance: The author faced a significant challenge: cross-fading 4MP images at $60\text{ fps}$ on a small SBC.

To achieve smooth transitions, GPU acceleration was required.

The Artwork Problem

A major discovery was that AirPlay only transmits low-resolution artwork ($\approx 500 \times 500$ pixels), which looks terrible on a 17" screen. To fix this, the author developed an out-of-band protocol extension within the audio player app to stream full-resolution imagery.

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🔌 System Integration

The device is designed to be seamless. When music starts, it automatically triggers the screen and the amplifier.

Audio Quality: The system supports CD-quality lossless audio via AirPlay, which meets the author's high standards.

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🚀 What's Next?

There is a possibility of a Kickstarter campaign for the Pentaton LP if there is sufficient community interest.

Stay Updated: Interested users can sign up at pentaton.app/lp/.

About the Pentaton App

The hardware is paired with the Pentaton app, which is currently a top-rated minimalist music player on the iOS App Store (4.9 Stars).

• Philosophy: A "no noise" approach to playback.
• Resources:
  • Consult the User's Guide for setup.
  • Visit r/Pentaton on Reddit for community support.
  • Leave a review on the App Store to support the project.
  • Join the newsletter to stay informed.