When it comes to unwrapping this particular curate’s egg, the place to start is with the functional versatility and the hardware that enables it. In operational terms, the I1 does indeed combine most of the functionality you’ll find in the C1.2 and P1 (assuming you add the optional phono-input cards). But in hardware terms, it’s a completely different animal. The dual mono DACs in the I1 are closely related to the ones that you can specify for the D1.5 (to turn the transport into a player). Undoubtedly fine in their own right, they don’t offer the sophistication DSP muscle or run the same PEtER algorithms as the DACs in the C1.2.
The analog inputs pass directly into an A-to-D stage, after which all adjustments (input gain, phono replay EQ etc) are performed in the digital domain. It is this reliance on digital control and the software that drives it that allows the I1 not just its astonishing array of functionality, but also underpins its audio performance. Take for example the volume control, so often a potential performance bottleneck in any analogue or digital control circuit. The I1 employs a clever hybrid solution, with large 6dB steps made in the analogue domain, while finer adjustments are made entirely in the digital domain – a solution that allows the topological elegance of digital control without eroding bit depth or the DACs’ resolution. It’s also worth noting that it’s an approach that’s yet to surface anywhere else in the CH range, further underlining the distinction between the I1 and the other CH products.
On either side of that digital core, the inputs and output circuitry are drawn from the rest of the range. The familiar card-cage construction allows use of the input modules from the C1.2 as listed above – although the dual-mono analogue input boards that are fitted to the I1 as standard are unique to this product, offering both inputs and the pre-out socketry. At the other end of the circuit, the power amplifier section in the I1 is based on the original A1 amplifier, now superseded by the larger and vastly more capable A1.5.
Not your starter for 10…
In many ranges, the integrated amp is seen as an introductory or ‘gateway’ product, the most affordable way for customers to buy into a company’s product line. In one sense, the same is true of the I1, but here we get to what is perhaps the biggest distinction between the integrated amp and the rest of the range. CH’s well-worn mantra of “upgradable, configurable, expandable and future proof” embodies the underlying ethos of a product line in which pretty much every box can be taken dual mono, with or without external power supplies, a ready made, cost neutral upgrade path that retains every bit of hardware you’ve purchased. There are two exceptions to this rule: the T1 Time Reference master clock (which is itself the upgrade!) and the I1. Unlike the C1.2, P1 or L1, there’s no option to go dual-chassis or even add an X1 external power supply. This is the product where the “expandable” part of the sales pitch grinds to something of a halt. In part, that reflects the digital nature of the unit, something that demands a single point for source contact (hence the three-box configuration of the C1.2) but it also reflects the financial and physical realities of the I1’s position and topology. What it also makes clear is that, unlike the C1.2 (which can be expanded to an all-singing, all dancing nine-box digital front-end) or the P1 and L1 (both of which can grow into four-box ‘true-mono’ configuration, with a separate chassis and power supply for each channel) the I1 is both an entirely separate platform and in terms of the CH range, an ‘endgame’ product.
