CH Precision C1.2 Upgrade Listening Impressions | HFA

Following the May 2022 Press Release, CH Precision has recently issued the new C1.2 DAC, an update of the longer-running C1 model. True to their upgradable/expandable design ethos, existing C1s can be fully upgraded to the C1.2 standard for the difference in price between the new and the older model, ensuring that the investment made by our end-users is both protected and updated, maintaining current, cutting edge digital performance without cost penalty.

As CH so beautifully puts it, no DAC is left behind!

The process of upgrading the C1 is relatively straightforward but requires careful handling of the delicate components while avoiding static discharges as the three vital circuit boards and their associated cables are swapped out. This is why the C1 to C1.2 upgrade is issued as a distributor or factory-installed kit.

All the upgrade components, including the optional 800×480 AMOLED display update to replace my older 480×272 display. DACs produced after July 2020 already have the latest display. Not shown is the new infrared remote control

The kit includes the three core components which are the MCU (main processing board), PSU (power supply regulator board), and BPLANE (the backplane board to which the option modules connect). In addition, you get a new acrylic front window with the new C1.2 model indication on it, a new laser-engraved back-plate with an updated serial number, a new infrared remote control, a USB key with new firmware, and all the necessary accessories. As you see, this is a very complete update. Remaining unchanged are only the power transformers, the input modules, and the DAC+Analog Output Stages. The way I see it, with this upgrade, you are getting almost an entirely new DAC!

These are the old swapped-out components from the C1

The physical process is finalized by updating the firmware of all the internal components and after this, the DAC can be used. However, it is stated very clearly in the upgrade documentation that calibration is mandatory after the upgrade, as the calibration of the C1.2 is different from the one in the C1, and that failure to do so will lead to degraded performance. While that may sound rather serious, it should be understood that precise calibration is of paramount importance for any multi-bit DAC chip. Thus, chip manufacturers already implement careful stages of calibration and this is one of the reasons why Multi-Bit DACs are more difficult to produce, more costly, and less popular than single- or low-bit DACs such as Delta/Sigma DAC chips.

The difference is that CH has taken the extra effort of implementing the DAC chips such that they can be further calibrated after installation in the C1 and C1.2. This is a process that should normally only be carried out once. The thing is, calibration should only be done after the unit has run for a couple of hours, and is well-warmed up.

Of course, I did listen to it uncalibrated.

What I was presented with by the newly updated and uncalibrated C1.2 was impressive on the one hand, as the sound was super-crisp, tight, direct, and highly rhythmic, but concerning on the other, as the sound was also quite square and technical, and with the flow and emotional involvement on a much lower level. Being well aware that the unit was basically new again and not only needed to warm up but also needed to run in to allow the new components and all the connections to settle, as well as requiring a calibration, there was a lingering doubt in my mind that the DAC’s character might have been taken in an entirely different direction.

I needn’t have worried, for as soon as I carried out the calibration a few hours later, the DAC was back to its old self in terms of emotional involvement, nuance, and flow, but now with a newfound level of transparency and insight.

My next listening tests would prove very interesting as they would unveil that the delta between the C1 and C1.2 is both obvious and subtle at the same time. Let me explain.

First, the 1.2 DAC does not sound entirely different from the C1. Of course not, some would say, since the DACs and output stages are not part of the upgrade. But I would counter that there are plenty of hardware and software examples where changes purely in the digital domain have a large effect on the sonics. I am happy to find that the C1.2 still adheres to the brand’s core standard, which (as I interpret it) is to be as neutral as possible while retaining all the music’s delicacy, refinement, and fluidity, in other words, being revealing without becoming clinical.

There’s one sonic difference, though. The original C1 DAC has always sounded fuller and more sonorous than the other CH products that I used, for instance, the L1 preamp. In 2018, when I was less experienced with CH products and initially used the DAC directly to the power amplifier, this led me to believe that the L1 sounded slightly lean when in fact it was the C1 that sounded slightly fulsome. Coming from a long Wadia CD player and DAC history, I was fond of this extra solidity, and my dipole speakers at the time also benefitted from this. But as it turns out, this was one aspect in which the C1’s performance could be further elevated.

With the C1.2 upgrade, the DAC has become more neutral and now sounds more in line with the L1 as well as the rest of the range. If all is well in the rest of the system, this is nothing but good news, and it sure is for me. That slight thickening/solidifying that the C1 added may have been enjoyable but it was also what made it not achieve the utter highest level of resolution, linearity and transparency compared to some more recent high-flying DACs, and in the latter two particular areas, even some less costly DACs. After the update, the C1.2 has not only addressed this and reaffirmed its position but it also retained all of its strong suits. For instance, it still offers a wide and deep soundstage, it’s still timbrally spot-on and very natural, well-focused, richly textured, and well-endowed in terms of transient attack and dynamic impact.

So far for the obvious results. What’s less obvious, and therefore all the more impressive is that the C1.2 is significantly more revealing, but without introducing any negative by-products. For instance, a very high level of precision is usually associated with dryness, an unforgiving or clinical quality, or a lack of emotional involvement. Let me be very clear on this: the C1.2 is in every way still the superbly musical and emotionally involving DAC that the C1 was, only better!

What the C1.2 is uniquely capable of doing is to be more discerning of differences in sources and source material. My various sources still sound recognizably like themselves, but more clearly so. The contrast between them has been enlarged. This is the subtle aspect that I was talking about earlier. It is not at all obvious in and of itself. It’s not like on a video display where increased contrast is always visible and can become overbearing. Rather, the raised resolution and transparency of the C1.2 only serve to reveal more of what’s offered at the source, nothing more, and nothing less. For instance, if a source is particularly dry or actually rather fluid, either aspect will be more obvious, but the C1.2 itself does not superimpose any character. Perhaps more importantly, while the C1.2 does indeed seem to offer a blacker background in that low-level details can be heard more clearly, this does not imply that these subtle sounds become staccato and shortened in decay. Rather, after the upgrade, the DAC seems to be even more capable of sounding fluid and continuous, but only if this is in the source, as it should be.

Conclusion

An upgrade is always exciting and sometimes a little scary because there might be a risk that the component’s character is pulled in a different direction. But in my book, CH has a superb track record. They are not a company to suddenly introduce a change to their sonic standards. Indeed, throughout each and every update, I found that the components retained all of their core assets while further raising the bar in certain aspects. With the C1.2 upgrade, the DAC has retained all of its virtues but has become even more neutral and even more revealing, without sacrificing even the slightest hint of refinement, delicacy, fluidity, decay, or flow. The C1.2 is in every way still the superbly musical and emotionally involving DAC that the C1 was, only better!

The original C1 has been an HFA favorite ever since I reviewed it. But there’s no way around it, the C1.2 is simply even better! As such, the HFA Awards migrate from the C1 to the C1.2.

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