Digital technology evolves rapidly. That immutable fact means that audiophiles investing in a good DAC will eventually pine for an upgrade. Yet, for the preponderance of DACs on the market there is no upgrade path. That’s because those DACs are built around off-the-shelf chipsets. I don’t mean to demean such chips; some of them are excellent and can be found in very good DACs, such as those from Japan’s Esoteric. But when the next generation of chips come out, the upgrade-seeking DAC-owner has no choice but to sell his hardware and buy the new model based on the new chips.

Then there are the handful of DACs that permit upgrades via firmware updates. Obviously, this is a far more convenient arrangement. The problem is that for most of these units, the “core” DAC functions (e.g., dCS’ proprietary Ring DAC) are implemented in hardware. Therefore, the firmware update can only tinker around the edges, so to speak. A slightly revised filter, for example. This explains why dCS, having developed an improved Ring DAC architecture, had to release a new APEX product series, with a hardware upgrade at the factory for existing owners to reap APEX’s benefits.

But what if you could have a brand-new, completely re-designed DAC without spending a dime or incurring the hassle of a hardware swap? That ideal situation would be possible only with a DAC whose digital machinations were implemented entirely in software. Sounds simple, right? But in practice this approach requires that the product be based on very powerful, flexible, yet fully programmable (and re-programmable) hardware. Generally speaking, that points to the use of Field Programmable Gate Arrays (FPGAs), which are not only expensive but require specialized coding skills.

CH Precision is one of the few companies that has been willing to go this route. The reason why is clear: CH has long been committed to easy, inexpensive field upgradeability for all its products. This philosophy explains the company’s use of modular card-cage construction and user-swappable function boards.

But the strategy reaches its zenith when it comes to the DAC functions of the I1 integrated amp, D1.5 disc transport, and C1.2 digital controller. Here, the use of powerful DSP and FPGAs on the DAC card allows for virtually unlimited upgrades—even complete rewrites, theoretically—with zero hardware costs and zero hassle. Further, CH Precision offers the firmware updates for free.

Theory Meets Reality

Those of you who read my review of the Metronome DSC know that, to my chagrin, it sonically clobbered my own CH Precision I1. In the process, the Metronome won a Golden Ear Award and became my new reference DAC/streamer.

However, unbeknownst to me, the restless folks at CH Precision were already working on a significant upgrade to the DAC within the C1 digital controller, which they would soon transfer to the I1 and D1.5. Their goals were twofold: 1) dramatically improve sonic performance via a wholesale revision of the DAC code; and 2) implement full MQA support. CH has now released the new I1 firmware, dubbed version 2.2.

This update is most decidedly not a case of tinkering around the edges. Among other things, the DAC now uses fixed-point rather than floating-point arithmetic. (See “A Conversation with Mr. C and Mr. H of CH Precision” for details about what changed and why.) Full MQA support is now so thoroughly implemented that, just as there is an assignable front-panel display color for analog and digital sources, there’s now a new color for MQA sources.

I got a preview of the new firmware at the 2022 Munich show. There, a system featuring all-CH electronics and Rockport Lyra speakers—playing Red Book CDs, no less—won my Best Sound of the Show Award. However, I had no idea how much of that fabulously realistic sound was due to the Rockports, the 10-Series CH components (which now form the heart of Robert Harley’s reference system), or the DAC firmware. The only way to find out was to try the upgrade in my own system.

A/B comparisons are highly elucidating when you can go back and forth at will. However, in this scenario, once I upgraded the firmware from “A” to “B,” as it were, there’d be no going back to A. The next best thing would be to establish an independent reference point, “X,” to which both A (before update) and B (after update) could be compared. Handily enough, I had the ideal “X” in the Metronome DSC.

I began by revisiting the comparison between the Metronome and the pre-upgraded I1. Consistent with my original review, the differences were not subtle. The first track I played was one of those that had impressed me so much in Munich, “True Love Ways” from the Buddy Holly CD From the Masters. Compared to the DSC, the I1 sounded dynamically and spatially flat. Flat, too, were the images, which on the Metronome had a holographic quality. In addition, bass was comparatively meager through the I1, and the CH didn’t deliver the richness that makes this track so seductive.

Similarly, on my standard test track, Michael Wolff’s “The Conversation,” the I1 again sounded compressed, and timbres had a sameness up and down the piano keyboard and at different volumes. This was in stark contrast to the timbral variety and vivacity delivered by the Metronome.

Having confirmed my original impressions of the I1’s DAC, it was time for the firmware upgrade. I was anxious to discover whether the changes it wrought were subtle, as such firmware upgrades on other DACs tend to be, or on the scale promised by the I1’s architecture. The upgrade process itself was simple. I downloaded the new firmware from the CH website to my computer, copied it to a thumb drive, plugged the drive into the USB service port on the back of the I1, and selected Upgrade Firmware from the CH’s menu. Some moments of suspense followed as I waited for the process to complete. Then I listened.

What I heard was no minor change. In fact, if I hadn’t done the upgrade myself, I never would have believed I was listening to the same DAC card in the same I1. This was a completely new DAC with an entirely different—and much better—sound. The I1, previously anemic sounding, now manifested the richness of the Metronome. “The Conversation” was transformed, with mesmerizing timbral diversity, fleshed-out images, and dynamics that were everything you’d expect from a CH component. Bass in the I1 DAC had gone from a liability to a strength. Indeed, the two DACs now sounded far more similar than different. Both were stellar.

Over time, as I listened more deeply, I found a few more minor differences between the two units. The Metronome, as you might expect from its name, has marginally better timing resolution, and its uniquely quiet background gives it a smidge more dynamic range. On the other hand, the post-upgrade CH has the edge when it comes to top-end smoothness, and its bass is more powerful and better defined. Preference will come down to personal taste and even the type of music one favors.

Conclusion

By now it should be apparent that CH’s first major DAC firmware upgrade is an unqualified success. Sonically, this new DAC is not only much improved; it goes toe-to-toe with the best DAC I’ve had in my system. And it cost me nothing! All this is thanks to CH’s forward-thinking, upgrade-minded architecture. Anyone with a CH integrated amp, transport, or digital controller should, if he hasn’t done so already, immediately download the latest firmware. He’ll be shocked at the upgrade he just received for nothing, with no hardware change required either. I only wish all DACs could do that.