FPGA DAC — Research & Architecture Sample

01 The Starting Point

A clear goal with no path

An established hi-fi audio company wanted to stop relying on off-the-shelf DAC chips and achieve independence by developing a proprietary FPGA-based digital-to-analog converter. This would help them avoid external product roadmaps, supply network problems, and design compromises. The objective was clear. How to get there was not.

Few audio companies have developed their own FPGA DACs, since the process is complex and there is no standard solution.

Delta-sigma DAC conversion on an FPGA was known to be technically feasible. However, the company lacked internal experience and did not know which algorithms were suitable, what implementation challenges might occur, or who could execute the project.

Known

Technically possible

Delta-sigma DAC conversion on an FPGA had been demonstrated. The technology existed.

Unknown

The way forward

Which algorithm and order of delta-sigma modulation to use, what noise shaping method to choose, and how the trade-offs would impact the final output. Whether the result would be efficient enough to work on FPGA hardware.

Known

The competitive context

Only a small number of companies had developed proprietary FPGA DACs. To our knowledge, they relied on highly complex implementations that required deep, specialized expertise.

Unknown

Internal capability

The company lacked internal FPGA expertise, so it was necessary to identify and manage the appropriate external specialist.

02 Mapping the Territory

Algorithm research, competitive landscape, constraints

The first step was to understand the challenge sufficiently to decide whether to proceed, including which approach to pursue and whether a successful outcome is realistic given the available resources. It was necessary to review the literature on DAC algorithms, primarily delta-sigma modulation, noise-shaping strategies, and the effect of algorithmic complexity on FPGA resource utilization.

The only company to publicly disclose a diagram of its FPGA DAC implementation selected a highly complex algorithm. However, research showed that a simpler approach could yield results comparable to those of a more complex approach.

The research produced an unexpected finding: a simpler delta-sigma conversion algorithm could achieve an impressive, high-quality audio output without the overhead of complex methods. This was a result of thorough, structured, elegant research, rather than a cost-reduction effort.

Existing implementations A company that has developed and disclosed a proprietary solution has relied on a highly complex algorithm that uses significant FPGA resources.

What the research revealed A simpler, well-crafted algorithm could deliver high-quality conversion audio output with fewer resources, enabling its deployment across an entire product line rather than just a flagship model.

03 Structuring the Execution

Algorithm development, specialist selection, sole knowledge bridge

Once the algorithm was defined, I refined the technical details, selected the FPGA implementation specialist, and became the sole technical knowledge bridge for the project. Overall, my work spanned four interconnected roles.

Algorithm

Developed the DAC algorithm by doing a thorough literature review, researching core signal processing methods, and creating several prototypes of differing complexity. Defined the final implementation steps, constraints, and quality requirements.

Specialist selection

Interviewed several FPGA consultants and selected one who really understood the problem and had the right technical skills. The consultant brought in the FPGA programming expertise, while the algorithm, direction, and all key decisions remained internal.

Knowledge bridge

Managed all communication between the FPGA consultant and the company. No one else in the organization possessed the full technical understanding of the project. All requirements, trade-offs, optimizations, and final specifications were coordinated through a single point of contact.

Ongoing direction

Kept the project on track throughout the implementation process by clarifying requirements, helping resolve roadblocks, evaluating intermediate results, and making sure the finished product met our highest standards.

Throughout the project, owners were kept informed of progress, requirements, and outcomes, while technical expertise was centralized.

04 A Related Judgment Call

Knowing what not to build

On a separate but related project, an audio processor for hi-fi home use, one of the most significant decisions was not to proceed with a particular approach.

Path not taken

Real-time change of a music tuning system: assessed and set aside

The company wanted to explore developing a hardware product that adjusts music tuning systems in real time during audio playback. After gaining sufficient understanding of possible algorithmic solutions, their complexity, and computational demands, it was clear that the path was not worth pursuing given the company's size and resources.

Spotting dead ends is one of the most valuable things in product development, even if their value is hard to see at the time, since they simply prevent wasted effort and resources.

05 Outcome

What the work produced

A proprietary FPGA DAC was created from the ground up - from research and algorithm design to a finished, shipping product. The final implementation uses a simpler, more efficient approach than any comparable publicly disclosed solution. This technology now powers the Schiit Audio Yggdrasil Singular, aka Byggy, and is intended for use across the company's product line.

The project called for someone willing and able to dive into the unknown, develop the algorithmic solution, select the right expert to help, and oversee the process from the big idea to the finished product.

06 What This Demonstrates

The pattern behind the project

What this work required

Navigating unknown technical territory independently. Entering a domain with no internal expertise and finding a viable solution through literature review, prototyping, and iterative assessment.

Identifying and directing the right specialist. The company needed external help to implement the algorithm on an FPGA. Success depended on knowing which skills to look for and how to collaborate with an expert from a different technical field while maintaining ownership of the core logic.

Being the sole knowledge bridge. Throughout the project, all technical synthesis, communication, and decision-making were centralized in a single point of contact, ensuring continuity and coherence.

Knowing which paths are not worth taking. The related audio processor project demonstrated the value of an early negative decision, made before resources were committed.