CH Precision I1 integrated amplifier

Integrated amplifiers
CH Precision I1
CH Precision I1 integrated amplifier

Let’s talk terms, and their inappropriateness at times. The I1 by Swiss electronics superstar CH Precision is – by the standard definitions of our industry – an integrated amplifier. To define a product as flexible and as powerful (in several senses) as the I1 in this way is like defining a surface-to-air missile as a ‘firework’. The more accurate definition of the I1 would be something closer to ‘a modular audio platform utilising a wealth of different daughter boards for operational optimisation plugged into a custom motherboard that includes an on-board amplifier component for high-performance single-box audio use.’ OK, maybe ‘integrated amplifier’ rolls off the tongue a little easier.

CH Precision uses the same chassis and design for its source components, preamplifiers, power supplies, and the one-case-does-all integrated I1. They all have the dual-dial single control, the distinctive left-hand panel curve and the magnetised-to-the-side remote handset. In fact, you can only tell them apart from the rear panel configuration and the subtle logo on the front screen. Otherwise they are functionally identical to one another, and even weight is no useful indicator, as they all fall into the ‘substantial’ class. This makes for a very consistent equipment stand if you start stacking them atop one another: in fact, the CH Precision devices all have removable threaded rod-like feet running through the four corners of the device, which could allow for stacking… though at least one pundit thinks make the CH Precision amps sound better when they are removed.

The I1 platform (I still can’t bring myself to thinking of it as an integrated amp) is best described by its rear panel. The basic layout has a set of large Argento speaker terminals at the extreme left and right of the panel, a central panel with IEC power inlet, switch, and fuse, a digital input HD board with AES/EBU, S/PDIF, Toslink and CH-Link HD for connection to CD Precision’s D1 CD/SACD digital front-end, and an analogue line input with RCA and XLR inputs. The rest in this basic guise is all a series of blanking plates. Additional modules include a USB Class 1.0 and 2.0 streaming input board, an Ethernet streaming input, and a current-mode MC phono input, itself with a full spread of EQ curves and also a Sync I/O board that allows the I1 to be enslaved to an external clock such as CH Precision’s T1 Time Reference using a coaxial cable. All connected to a motherboard layout with 2x 100W power amp stage. We went with a model that included all the options. 

Depending on input, the platform operates in the digital domain at 384kHz/352.8kHz from input to that Class A driver with Class B follower power amp stage, complete with CH’s own ExactBias biasing system. This is not like most integrated amplifiers, but more akin to a Vitus design – a power amplifier with benefits! The amplifier itself features a fully shielded 1kVA power transformer and has something in the region of 100,000µF of reservoir capacitance on tap. And yet, thanks to some extremely high-grade diodes in the bridge rectifier stage, it sounds deceptively fast like a small integrated design.

The modules are key to the story, though. It’s best to think of each one as a small version of some of CH Precision’s separate components (because actually that’s what they are). So, the digital input board works to 24bit, 192kHz/DSD64 precision on its standard inputs, or up to 32bit, 768kHz/DSD128 on the CH Link that you would use with a CH Precision D1 disc transport. The MC board allows up to two different turntable inputs (balanced or single-ended) and can cope with any load the right side of 100mΩ, with adjustable gain. And so on, all fed through a volume control that moves in precise 0.5dB steps from -100dB to +18dB.

The only real problem with all of this is describing it without making it sound bewildering. But it’s like a bespoke suit; it’s effectively made for you, and once complete fits you perfectly for longer than anything ‘off-the-peg’. Its flexibility is not a weakness or a sign of indecision on the part of the manufacturer; it’s a conscious programme to make sure you have an amplifier designed specifically for you.

An interesting aside is the connectivity of the streamer board. Unlike most on-board devices in this category, there is no provision for wireless connectivity as standard. Instead, the Ethernet connection is designed to attach to a wireless router (maybe via a network switch), with devices like a NAS drive also hanging off that external network. This is, I feel, a better way of isolating the potential ingress of radio frequency interference, especially if you use acordon sanitaireof some description between network and audio systems. Of course, this means less of an ad hoc approach to networking, which goes some way against the ‘Plug ‘n’ Play’ notions held by many companies, but if you are going to do a job, do it properly.

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