Speek amp

speek

A modular speaker system. Right now, it has a couple of boards:

• Speek Amp: This is the flagship amplifier. It's a hybrid 2.1 design using the TPA3116D2 chip. It's built to handle 4Ω speakers. It outputs lines for a mono subwoofer, two stereo woofers, and two stereo tweeters.
• Speek RX: This is a Bluetooth audio receiver. It runs off of a qfn esp32 D0WD v3 and has a built-in headphone amp, or a normal line out for chaining.
• Speek PSU: This is a supporting PSU board. It has a USB-C PD trigger (for quick tests) and a barrel jack port for proper power (needed to power real flagship drivers). It can be used as a stable power source for pretty much anything. Note that the barrel jack supplies 24V while PD gives 20V.

On modularity:

• Each board is self-contained and can be used on its own. However, they can also all be used together.

I made this project to get into audio systems! I've visited some hi-fi listening rooms, and I thought it was really cool. But I think the speaker industry is way overpriced. People commonly pay several thousand dollars for nice speaker systems! I wanted to build one myself for a few hundred. It might not be as high-fidelity, but it'll be my own, which is pretty cool. And you or I probably wouldn't be able to hear the difference.

Right now, enclosure design is out of scope. This repo holds just the boards, and the boards are complete

[Please Read] Where do I find everything? AKA checklist

What's with the monorepo?

A monorepo just means everything lives in one repo instead of splitting each board into its own. All the files are here: each board gets its own top-level folder (speek-amp, speek-rx, speek-psu), with docs in docs and the overall BOM at BOM.csv. I went with a monorepo because even though there are multiple boards, it's really one project overall, so it made sense to keep them together.

Checklist:

• A good README
• Source files for your project
  • This includes hardware design, firmware, 3D assemblies, etc
• Production files (if applicable)
  • You'll find gerbers, fabrication BOMs, and PnP files at the following locations:
    • Speek Amp: speek-amp/PCB/speek_amp/production_real
    • Speek RX: speek-rx/PCB/speek_rx/production_real
    • Speek PSU: speek-psu/PCB/speek_psu/production_real
• [N/A] JOURNAL.md if journalling on Git
• BOM.csv complete with functioning links (where applicable)
• A short description of what your project is
• A couple sentences on why you made the project
• PICTURES OF YOUR PROJECT
• A screenshot of your PCB, if you have one
• A screenshot of your schematic, if you have one
• A wiring diagram, if you're doing any wiring that isn't on a PCB
• A BOM in table format at the end of the README
• A STEP file of your assembly: speek_assembly.step

How to use?

Mostly it's plug-and-play after assembling everything. The exception is Speek RX, which requires firmware to be flashed. See speek-rx/README.md for more info, but in short, all you should need to do is

cd speek-rx
cd firmware
pio run -t upload

For wiring your speaker drivers, the silkscreen should coach you through that.

Wiring Diagram

Gallery

Speek Amp

Speek RX

Speek PSU

Schematics

Speek Amp

View on KiCanvas

Speek RX

View on KiCanvas

Speek PSU

View on KiCanvas

PCBs

Speek Amp

View on KiCanvas

F.Cu	B.Cu

Speek RX

View on KiCanvas

F.Cu	B.Cu

Speek PSU

View on KiCanvas

F.Cu	B.Cu

About cost

Speaker drivers are included in the BOM, but I'm not asking for them here. I will for sure pay for them out of pocket or figure it out. They are included in the BOM for record-keeping purposes. Basically they are the drivers that I sourced to base the amp design off of.

For the rest, I have a significant amount of credits already lying around, and I've got a JLC $20 coupon.

TLDR: I've heavily BOM-optimized and this is pretty much how much the PCBs are going to cost. Don't worry about the grant not covering everything, I'll pay the rest out of pocket

Overall BOM

Fabrication BOMs

LCSC part numbers missing? Don't worry, it's a DNP component that I'll hand solder myself. It's in the table above.

Speek Amp

Speek RX