I1 Universal Integrated Amplifier

I1 Universal Integrated Amplifier

The ultimate integrated solution for discerning audiophiles looking to achieve ultra-high-end performance from a compact personalised audio system. The I1 Universal Integrated Amplifier distills all of the CH Precision expertise, design philosophy and most critically the versatility and modularity of their 1-Series in a single box solution.

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The I1 integrated amplifier is possibly the most complex project that CH Precision has ever undertaken – and the most versatile product we have ever produced. Imagine the core qualities and capabilities of the C1 DAC Controller and A1 Amplifier combined in a single box. Now throw in the choice parts of the L1 Line-stage and add the option of a P1 phono-stage, all combined in a single, standard CH chassis and you begin to get the picture.

The I1 is supplied in standard form equipped with four digital inputs (CH-Link HD, AES/EBU, S/PDIF and TosLink – although a second identical digital input board can be added in the spare chassis slot if you need the extra connections) one set of balanced and two pairs of single-ended analogue inputs. The factory fitted Ethernet Control Board, which allows the unit to be remotely accessed, configured and controlled via the CH-Control Android App, can be replaced with a full network streaming capable Ethernet input and a separate, asynchronous USB input card can be added to enable connection of computer sources for file replay.

The discrete, fully-complementary analogue input boards can be fitted with additional internal circuit blocks that allow owners to convert either or both of the RCA analogue inputs into current-sensing MC phono-inputs, complete with switchable replay EQ settings for RIAA, eRIAA, Decca, Columbia, EMI and Teldec (DGG) curves. Finally, a Clock-Sync board allows you to slave the I1 to external master clocks, or designate its internal clock as the system master. Dominating the interior of the I1 chassis, you’ll find a massive 1000VA transformer that’s more than capable of supporting the 100 watt/channel into 8 Ohms rated output; in combination with the 100.000uF of reservoir capacitance it allows the output stage to handle awkward loudspeaker loads with ease.

How did we pack so much functionality into a single chassis? By leveraging the power of sophisticated software control, modular construction and advanced digital processing.

The I1’s volume control is a remarkable hybrid design, that uses an R-2R resistor ladder in the analogue domain for setting coarse levels, with fine adjustment taking place in the digital domain, a combination that allows incredibly precise level control without eroding bit depth, resolution or dynamic range. Likewise, the I1’s advanced analogue-to-digital conversion stage allows us to set overall cartridge gain and replay EQ in the digital domain, providing unparalleled phono replay flexibility, accuracy and features in an integrated unit. You mean we turn the analogue inputs into digital? Yes – but if you don’t tell your friends they’ll never know. Indeed, many listeners swear that the I1’s phono-stage delivers some of the finest analogue sound they’ve ever enjoyed! Which tells you that its digital replay is pretty impressive too…


Input Modularity

The I1 Universal Integrated amplifier has been developed around the central philosophy of modularity. A Swiss army knife of audio design.

  • AES/EBU, coaxial S/PDIF and optical TOSlink digital inputs
  • I2S proprietary CH Link HD digital input
  • balanced XLR and single-ended RCA analog inputs
  • current-sensing RCA phono input, ideal for MC cartridges, RIAA, eRIAA, Emi, Columbia, Decca and Teldec EQ curves, optional
  • RJ-45 Ethernet audio input, UPnP, Tidal, Qobuz and Web radio compatible, optional
  • USB class 1.0 and 2.0 audio input for direct connection to a computer, optional


Processing & Clocking

  • proprietary CH-PEtER synchronous spline-based data upsampling, converting any incoming audio stream to DXD resolution
  • resolution enhancement for audio material of less than 24 bits
  • two ultra low jitter digitally controlled VCXO oscillators, one per time domain

D/A Conversion

  • individual multibit Delta-Sigma converter per channel
  • pure class A, fully symmetrical analog design
  • fully discrete, ultra low noise, high slew rate design

Volume Control

  • hybrid digital and analogue volume control
  • tight tolerance high-grade metal film resistors
  • 120dB range in 0.5dB steps
  • volume pre-trimming on each analogue input
  • phono input adjustable gain
  • post volume control stereo balanced line-level analogue outputs

Amplification Stage

  • pure class A ultra low noise driver and class AB pure follower power stage
  • feedback Ratio adjustable from 0% – local feedback only – to 100% – global feedback only – in 20% steps
  • exactBias circuitry
  • power transistors and heat sink temperature monitored
  • no output relay
  • customized Argento loudspeaker binding posts

Power Supply

  • shielded 1000VA power transformer
  • hyper fast soft recovery diode bridge rectifiers
  • total of 100’000uF reservoir and filtering capacitors


“the I1 is definitely as close to audio Nirvana as any compact audio component has transported me.” – DENNIS DAVIS, THEAUDIOBEAT.COM (read in full here)

“A (very) few integrateds can match (the I1) in one area or another, but I know of nothing with a comparable combination of pedigree, versatility, footprint, expandability, upgradability, value, and world-class sonics.” – ALAN TAFFEL, THE ABSOLUTE SOUND (read in full here)

“This is one of the best integrated amplifiers you can buy.” – ALAN SIRCOM, HIFI+ MAGAZINE (read in full here)

“It is an amp with few peers at any price point, not only sonically, but for build quality and available options.” – RAFE ARNOTT, AUDIOSTREAM (read in full here)


Digital inputs

CH Link HD High Definition Link

PCM 16 to 32 bit / up to 768kHz
DSD 1 bit / 2.8224MHz & 5.6448MHz, cyphered

AES/EBU XLR connector, up to 5Vpp, 110Ω

PCM 16 to 24 bit / up to 192kHz
DSD 1 bit / 2.8224MHz (DSD64), DoP encapsulated

S/PDIF RCA connector, up to 1Vpp, 75Ω

PCM 16 to 24 bit / up to 192kHz
DSD 1 bit / 2.8224MHz (DSD64), DoP encapsulated

Toslink Optical connector

PCM 16 to 24 bit / up to 192kHz
DSD 1 bit / 2.8224MHz (DSD64), DoP encapsulated

Analogue inputs

Inputs type 1x Balanced XLR, 94kΩ or 600Ω selectable input impedance, 8V RMS maximum input level
2x Single-Ended RCA, 47kΩ or 300Ω selectable input impedance, 4V RMS maximum input level
Input stage Discrete fully differential input stage
A/D conversion DXD 24 bit / 384kHz direct conversion, low-pass filter above 30kHz to suppress modular HF noise

Phono inputs (optional)

Operating mode Current-sensing, optimal for low impedance MC cartridges
Input connector 2x RCA, shared with line level analog input (line/phono mode configurable per connector)
Input stage Current-sensing virtual ground, I/V trans impedance gain, A/D conversion, digital EQ
Input impedance <100mΩ virtual ground
A/D conversion DXD 24 bit / 384kHz direct conversion
EQ curves RIAA, eRIAA, Emi, Columbia, Decca or Teldec, DSP-implemented with <0.01dB accuracy

Computer inputs (optional)

USB input asynchronous mode

PCM 16 to 32 bit (fixed point) / up to 384kHz
DSD 1 bit / 2.8224MHz (DSD64) & 5.6448MHz (DSD128), DoP mode only

Ethernet input asynchronous mode

PCM 16 to 32 bit (fixed point) / up to 192kHz (384kHz for uncompressed formats)
DSD 1 bit / 2.8224MHz (DSD64), 5.6448MHz (DSD128) & 11.2896MHz (DSD256), native DSD and DoP

WAV, AIFF, FLAC, ALAC, AAC, MP3 format supported in PCM
DSF, DFF format supported in DSD

Synchronisation (optional)

 Clock input BNC, 0.5Vpp to 5Vpp, 75Ω or Hi-Z

44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz, 384kHz
22.5792MHz, 24.576MHz
100kHz, 10MHz

 Clock output 2x BNC, 2Vpp, 75Ω

input sampling frequency or clock loopback if externally synchronised

Analogue outputs

Line level outputs Balanced (XLR): 4V RMS – Volume Controlled stereo outputs
Power outputs 2x 100W RMS/8Ω, 2x 175W RMS/4Ω


Display 480×272 pixels, 24bits color, AMOLED
Mains operation Selectable 100V, 115, 230V AC, 47-63Hz
Fuses value and location Standby fuse (white holder): 250mA T (230V AC), 500mA T (100V AC, 115V AC)
Main fuse (black holder): 10A T (230V AC), 16A T (100V AC, 115V AC)
Power supply consumption <1W (standby), 1’000W max in operation
Dimensions/Weight 440 x 440 x 133mm (W x D x H), 33kg
Remote control IR Remote control provided, RC5 codes
Ethernet based system control via the Android CH Control App

Upgrades & Accessories


User Manual
Manufacturer Website


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