Hi everyone,

I'm an audio hobbyist and a passionate electrical engineering student. I originally came up with this project as a way to sharpen my engineering skills, with the ultimate goal of potentially turning it into a business if the community finds value in it. I'd love to show you what I've been working on over the past couple of months, where the project stands today, and get your honest feedback and suggestions.

LytrixLabs is an idea for a modular, future-proof audio system. It combines high-resolution 32-bit/768kHz DACs, dedicated DSP, and high-performance integrated Class-D amplification. By designing a fully modular ecosystem, you can expand or change your setup over time without replacing the entire unit, allowing the system to adapt as new audio technologies or DAC chips are developed.

The plan is to house this in a chassis featuring solid wooden side panels, a brushed aluminum finish, a 7-inch IPS touchscreen for the UI, and a large satisfying volume knob.

Quick Overview of the Device

The internal processing engine is powerful and designed to handle up to ~24 audio channels at 32-bit/768kHz, which opens the door for spatial audio decoding through eARC. It also features a dedicated DSP for audio processing and potential room correction. On the input side, up to ~12 channels are available, making room for phono preamplifier/ADC modules, balanced XLR inputs, or traditional line-level sources.

If this works out, I plan to create an open-source, well-documented template for the audio modules. This will allow anyone with the technical know-how to design or modify their own modules to suit their exact system needs.

Preliminary Specifications

• Passive Cooling: Entirely passively cooled; no fan noise in your listening room.
• Power: Up to 300W of continuous power draw across the amplifier modules, with a 500W+ peak.
• Connectivity: HDMI eARC input, SPDIF input & output, 1Gb Ethernet, and Bluetooth 5.3 & WiFi 6 support.
• Modular Capacity: 6 rear module slots, supporting 4 audio channels in both directions per slot.
• USB Ports: 1x USB-C for digital audio input, 1x USB-A for playback from storage drives, firmware updates, and calibration microphone input.
• Control: Trigger outputs allow for powering external equipment on/off automatically. Combined with HDMI-CEC, you get a one-click system startup. A classic IR receiver is included for remote compatibility.
• Smart Monitoring: Real-time power and temperature sensing on every module. It can automatically apply gradual adjustments to output gain to match your specific setup, ensuring maximum safe output without hard voltage drops or overheating.

Planned Modules (Would love your suggestions!)

All modules integrate dedicated DACs and ADCs supporting up to 32-bit/768kHz audio. They utilize COG and film capacitors in the audio path, along with low-distortion op-amps and high-performance integrated Class-D chips.

Outputs:

• 1x 200W amplifier module
• 2x 100W amplifier module
• 4x 50W amplifier module
• 4x Line-level RCA outputs
• 4x Balanced XLR outputs
• 3.5mm & 6.3mm headphone outputs with high-impedance support

Inputs & Others:

• 1x RCA & 1x Phono inputs
• 2x Balanced XLR / 6.3mm combo inputs
• 5:1 HDMI 2.1 switch module

What I've Achieved So Far

For the physical connection, I'm using a standard PCIe form factor interface for the modules. It's affordable, widely available, and ensures a solid mechanical hold. The current test carrier board simply breaks out the audio signals and provides power rails to the module to verify the basic architecture.

The Module Breakdown (Component Selection & Layout)

The layout focuses purely on solid electrical engineering principles to ensure good signal integrity:

1. Isolation: The DAC chip (AKM AK4493) is placed at the top left, furthest away from potential high-frequency switching noise or crosstalk. Low-noise linear regulators (LDOs) provide clean power rails to the DAC.
2. Buffering: An op-amp stage (OPA1642) acts as a buffer to prevent loading down the DAC, paired with linear COG capacitors.
3. Amplification: The Class-D amplification is handled by the TI TPA3255 IC, which is one of the best integrated Class-D chips on the market right now. It is situated on the right side near the physical speaker outputs, right next to its output filtering stage.
4. Telemetry: A dedicated power sensor monitors real-time power consumption for safety and system matching.

Of course, hardware prototyping rarely goes perfectly on the first try. I made a couple of minor routing mistakes on this first revision, but with a few minor bodge wires, I managed to get the core features up and running. Most importantly, it gave me a clean list of corrections for the next board revision.

Eventually, I got the core software written and successfully output a clean sine wave over USB.

I don't own specialized audio analyzer equipment to post definitive THD+N or SNR graphs. I also don't own high-end speakers to fully evaluate it, and I haven't done extensive listening tests yet anyway, as I moved on to designing the motherboard right after this milestone. From the brief testing I did do, the noise floor was completely silent and the sound was clean, but I can't claim anything definitive without real measurements.

The Motivation Behind It All

This entire project stemmed from my own frustration when trying to set up a digital crossover for my electrostatic speakers, which provide separate audio inputs for the low frequencies and high frequencies. I wanted a single integrated amplifier to handle the DSP, routing, and amplification under one roof rather than a messy "cable-spaghetti" pile of separate DACs, standalone DSP units, and multiple external amps.

There is still a ton of work to do, and progress can be slow since I'm studying full-time and working on the side, but it’s an incredible learning experience.

I would absolutely love to hear what modules you think are missing, your thoughts on the modular concept, or any features you'd want to see in a device like this. If you’re a fellow engineer, check out my other posts for a couple more details. I'll also do my best to answer any questions you may have in the comments! (: