CH I1 User manual

I1 Universal Integrated Amplifier
User Manual
Rev 1.0 I1 User Manual 1

2 I1 User Manual Rev 1.0

Dear Valued Customer,
We are onored t at you c ose t e I1 Universal Integrated Amplifier for your audio system. Our team devoted every effort to
design and manufacture t is ig est-quality versatile and future-proof product and is proud to present it to you. We wis you
ours of enjoyment from your music collection wit t e I1 Universal Integrated Amplifier installed in your system.
Before you embark on your musical journey, we kindly request your special attention regarding t e information contained in t is
manual. T e I1, as you will discover in t e following pages, is a Swiss precision product designed for ultimate performance and
flexibility. However, reac ing sonic excellence from your audio system requires your unit to be set up and operated correctly and
t is w at t is manual is all about. If you ave any questions or require assistance, please don't esitate to contact your aut orized
dealer.
We ope you will enjoy your I1 for many years to come.
T e Concert as just begun...
Cossy F.
Heeb T.
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4 I1 User Manual Rev 1.0

Table of contents
1 Product ig lig ts......................................................................................................................................................................7
1.1 Modular arc itecture and slot-in boards............................................................................................................................9
1.2 Amplifier feedback control................................................................................................................................................9
1.3 Power amplifier bias adjustment.....................................................................................................................................10
1.4 System clocks.................................................................................................................................................................10
1.5 Volume control...............................................................................................................................................................10
1.6 Rigorous metal work construction...................................................................................................................................10
1.7 Power supply..................................................................................................................................................................11
2 I1 option boards......................................................................................................................................................................12
2.1 Digital inputs and CH Link (DIGITAL_IN).........................................................................................................................12
2.2 Et ernet audio streaming input (ETHERNET_IN)..............................................................................................................12
2.3 USB audio input (USB_IN)..............................................................................................................................................12
2.4 External clock sync ronization (SYNC_IO)......................................................................................................................12
2.5 MC cartridges p ono input (PHONO_I1).........................................................................................................................13
3 System setup examples...........................................................................................................................................................14
3.1 Sources connection: I1 + Et ernet streaming + P ono + D1 setup..................................................................................14
3.2 Bi-amplification: I1 + A1 setup.......................................................................................................................................15
3.3 Improved clock accuracy: I1 + T1 setup..........................................................................................................................16
4 Read carefully before use........................................................................................................................................................17
4.1 Package content.............................................................................................................................................................17
4.2 Safety notice..................................................................................................................................................................17
4.3 Mains supply..................................................................................................................................................................18
4.4 Transport and packaging................................................................................................................................................18
4.5 Cleaning.........................................................................................................................................................................18
4.6 Maintenance and Servicing.............................................................................................................................................18
5 Installation..............................................................................................................................................................................19
5.1 Unpacking......................................................................................................................................................................19
5.2 Removing t e transportation screws................................................................................................................................19
5.3 Unit positioning..............................................................................................................................................................19
6 Connections.............................................................................................................................................................................21
6.1 Loudspeakers outputs.....................................................................................................................................................22
6.2 Preamplifier output........................................................................................................................................................22
6.3 Analog line and p ono inputs.........................................................................................................................................22
6.4 Processor input...............................................................................................................................................................23
6.5 Digital audio inputs (DIGITAL_IN)...................................................................................................................................23
6.6 Type B USB port (USB_IN)..............................................................................................................................................23
6.7 BNC input and outputs (SYNC_IO)..................................................................................................................................23
6.8 Et ernet port..................................................................................................................................................................23
6.9 Type A USB port..............................................................................................................................................................23
6.10 Ground connections......................................................................................................................................................23
6.11 Mains socket and voltage selection...............................................................................................................................24
6.12 Fuses............................................................................................................................................................................24
7 Operation................................................................................................................................................................................26
7.1 Front panel.....................................................................................................................................................................26
7.2 User control knob...........................................................................................................................................................27
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7.3 Remote control operation...............................................................................................................................................28
7.4 C anging t e remote control batteries............................................................................................................................29
7.5 Operating modes............................................................................................................................................................30
7.5.1 Normal mode........................................................................................................................................................30
7.5.2 S ortcut Mode.......................................................................................................................................................31
7.5.3 Menu mode...........................................................................................................................................................34
8 T e I1 menus..........................................................................................................................................................................37
8.1 AUDIO menu..................................................................................................................................................................37
8.2 INPUT menu...................................................................................................................................................................38
8.3 DISPLAY menu................................................................................................................................................................39
8.4 SHORTCUTS menu...........................................................................................................................................................39
8.5 NETWORK SETTINGS menu..............................................................................................................................................40
8.6 FACTORY menu...............................................................................................................................................................41
9 Firmware update.....................................................................................................................................................................42
9.1 Preparing t e USB Stick..................................................................................................................................................42
9.2 Updating t e unit's firmware..........................................................................................................................................42
9.3 Emergency firmware update procedure...........................................................................................................................42
10 Clocking considerations..........................................................................................................................................................44
10.1 Only ever one clock master..........................................................................................................................................44
10.2 I1 wit out SYNC_IO board............................................................................................................................................44
10.3 I1 and D1 wit SYNC_IO board....................................................................................................................................45
10.4 T1 + I1 and D1 wit SYNC_IO board............................................................................................................................47
10.5 I1 wit USB_IN board+ Computer................................................................................................................................48
10.6 I1 wit ETHERNET_IN board+ Computer.......................................................................................................................49
11 Troubles ooting.....................................................................................................................................................................50
12 Specifications.........................................................................................................................................................................52
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1 Product highlights
CH products are proudly designed and manufactured in Switzerland by CH Precision Sàrl. Our engineers put toget er all t eir
know- ow, expertise and ingeniousness to bring you t e I1, a top performance future-proof modular stereo integrated amplifier
wit Et ernet control capabilities and USB flas -drive firmware update. T e I1 is t e gateway to t e CH world. It combines t e soul
and essence of four products from t e 1-Series of products: T e P1 p ono stage, T e C1 converter, t e L1 preamplifier and t e A1
power amplifier. Like t e C1, t e ub of t e I1 is digital. T e analog inputs (line and p ono) are converted into t e digital domain
w ile t e digital inputs are up-sampled. T e digital stream is processed and finally converted to t e analog domain at
352.8kHz/384kHz. T e 2-c annel amplifier is a purely analog power stage wit a class A input stage and a class AB output stage.
It is derived from t e A1 amplifier circuitry and t erefore features t e ExactBias circuitry as well as t e unique variable global vs
local feedback ratio.
Like all of CH Precision products, t e I1 is ig ly versatile and modular. T e base model comes wit four digital inputs, t ree
analog line inputs, an integrated digital to analog converter, a ybrid volume control and t e two c annels of power amplification.
However, t e back of t e unit is fitted wit slots into w ic optional input boards can be fitted. T e I1 can be customized to t e
requirements of a specific system. Option boards can be eit er factory-fitted or added easily at a later stage. Many option boards
are available: Digital inputs boards providing CH Link, AES/EBU, coaxial S/PDIF and optical TOSLINK inputs, Et ernet Audio
Streaming, USB Audio Streaming, current-mode p ono inputs dedicated to MC cartridges and External clock sync ronization input
and output board.
Versatility is apparent in t e way t e I1 can play center stage in an evolving and growing audio system. T e approac taken by CH
Precision is to enable I1 users to expand and refine t eir system from a single-box solution to a more complex and more refined
system:
•Connect t e I1 preamplifier balanced outputs to an A1 or M1 2-c annel power Amplifier and enable loudspeaker bi-
amplification.
•Connect a D1 CD/SACD Drive using t e proprietary CH-Link input and create t e ideal transmission pat between disc
and digital to analog converter.
•Connect a T1 10MHz Time Reference to t e input of t e I1 External clock sync ronization option board and benefit from
t e T1 ultra-accurate and stable clock reference.
•Use a C1 digital to analog converter to extract t e digital to analog conversion out of t e I1. All t e I1 digital inputs
boards, including t e Et ernet and USB audio streaming board and t e external clock sync ronization are removed from
t e I1and fitted at t e back of t e C1. T e C1 analog outputs are connected to one of t e I1 Analog input configured as a
Processor input (see c apter 6.4). By doing so, t e I1 turns into a pure analog 2-c annel power amplifier.
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I1 main components
(1) Audio speaker terminals
(2) Factory-fitted monaural analog input boards. Can be optionally equipped wit current mode p onostage module
(3) Optional clock in/out sync ronization board
(4) Mains switc and power cord receptacle (on back panel)
(5) Factory-fitted digital input board
(6) Input slot. Can be optional y fitted wit a digital input board or a USB audio input board
(7) USB (firmware update) and RJ-45 (control and optional Et ernet audio streaming) board
(8) Output coil for HF immunity
(9) Adjustment s afts and screws
(10) Digital power supply regulation board
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(11) Heatsink-mounted monaural amplifier boards
(12) Dual concentric pus control knob
(13) Display (on front panel)
(14) Standby power transformer (ensures green mode standby)
(15) Main power transformer
(16) Analog power supply regulation board
1.1 Modular architecture and slot-in boards
T e slot-in boards section consists of a vertically-mounted backplane board w ere optional boards can be plugged into. Optional
boards provide audio functionality and connectivity to ot er pieces of equipment. T ere are six types of slot-in boards:
•PHONO_I1: analog input piggyback module t at provides current-mode p ono inputs dedicated to MC cartridges
•DIGITAL_IN: provides CH Link, AES/EBU, coaxial S/PDIF and optical TOSLINK digital inputs (one board is factory fitted)
•USB_IN: enables bit-exact, ultra low jitter playback of ig resolution audio files directly from a computer
•SYNC_IO: provides advanced clock sync ronization options (1 clock in, 2 clocks out)
•ETHERNET_IN: used for Et ernet audio streaming. Connects to a UPnP/DNLA compatible server (eg. NAS). Browse music
from a tablet using t e CH Control app
•CONTROL: provides a USB port for software upgrade and an Et ernet port for command
T ere are five slots in t e I1. Two of t em can be populated wit any combination of DIGITAL_IN and USB_IN boards. One of t em
is dedicated to t e optional SYNC_IO board. Anot er one is factory fitted wit a CONTROL_IN board but can be upgraded to a
ETHERNET_IN board to enable Et ernet audio streaming capability. T e last slot is factory fitted wit stereo analog lines inputs and
can be upgraded to add t e PHONO_I1board. See c apter 2.5.
1.2 Amplifier feedback control
One of t e I1's most unique features is its user-controllable amplifier feedback. T is feature controls t e ratio between t e global
and t e local feedback applied in t e I1's amplification stage. Global feedback takes a portion of t e output signal after t e power
stage and feeds it back to t e input of t e amplifier. T is ensures a very low output impedance and low distortion figures. Local
feedback, on t e ot er and, does not include t e output stage and lets t e latter operate in open loop mode. T is favors small
signal details and timing.
As a rule of t umb, a ig er ratio of global feedback is preferred for grip and control in t e low frequencies w ereas a lower ratio
is preferred for speed and details in t e ig frequencies. T is rule is owever not absolute as eac speaker and cross-over is
different and we ig ly recommend to experiment wit various settings to find t e best matc wit t e connected loudspeakers,
especially if t e I1 is driving a complete full bandwidt loudspeaker.
In multi-amplification systems, different feedback settings are commonly used for t e various speaker sections opening a w ole
new level of performance. We recommend to start wit pure local feedback and increase t e global feedback until t e bass are
controlled enoug to your personal taste. Feedback settings can be adjusted on t e fly from t e I1 front panel menus or from t e
CH Control app.
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1.3 Power amplifier bias adjustment
T e I1 provides an advanced bias control circuitry (ExactBias) t at not only follows slow temperature variations, but also accurately
takes into account all t e dynamic aspects induced by transients in t e musical content.
1. System clocks
T e first requirement to ac ieve perfect timing is t at audio data are fed into t e DAC c ips, sync ronous to a jitter-free clock. T is
is w y two ig -precision low-drift audio crystal clock oscillator (22.5792 MHz for 44.1 kHz multiples and 24.576 MHz for 48 kHz
multiples) are located only a few cm away from t e DAC c ips. T e clocking section as its owns dedicated power supply fully
decoupled (complete galvanic isolation) from all noisy digital signals.
In order to be sync ronous to t e incoming audio signal, t e crystal oscillators (VCXO) are fine-tuned using a voltage controlled
feedback computed by a proprietary algorit m. Performances of t is “digital p ase-locked loop” (digital PLL) as a jitter rejection
below 0.1 Hz, w ile frequency tracking is ac ieved t roug sub 0.1 PPM correction steps. P ase alignment is also guaranteed wit
a +/-2.5 microsecond accuracy.
1.5 Volume control
T e I1 integrated amplifier as a ybrid volume control. T e word ybrid describes a volume control set bot in t e analog domain
as well as in t e digital domain. It is a combination of fine steps applied in t e digital domain and derived from t e C1 D/A
controller software algorit ms in between coarse analog attenuation steps using t e tec nology developed in t e L1 line
preamplifier.
Please note t at t e I1 can be also be configured as a pure 2-c annel power amplifier w ere t e audio signal remains in t e
analog domain wit no A/D nor D/A conversion at all. In t is mode t e volume is fixed and t e level is equivalent to a volume
control set to no attenuation! T is mode is to be used wit an external volume control unit connected upstream to t e I1.
1.6 Rigorous metal work construction
T e I1 c assis is made of ig -grade aluminum alloy wit no visible screws on t e front, top and side panels. First class mec anical
and c emical surface treatments provide its luxury finis . Pin assembly of all c assis elements enables smoot joints between
metal parts w ile screws every 6cm ensure protection against electromagnetic interferences.
T e unit rests on four stainless steel feet. Eac foot is fitted wit an elastomer ring to sit on delicate surfaces but is also equipped
wit eig t adjustable steel spikes to fine tune t e unit’s position. Horizontal leveling is accomplis ed using t e provided
screwdriver t roug t e four adjustment s afts accessible from t e top of t e unit. Most importantly, t e steel spikes serve as
vibration evacuation c annels. W en used wit t e provided CH Support discs, t ey create t e most effective way to c annel
unwanted vibrations away from t e unit.
Finally, for units t at are stacked on top of eac ot er, stacking covers are provided to interface wit t e spikes of t e unit above
(see section 5.3). Vibrations from t e upper unit is transmitted by t e stacking cover to t e s aft of t e lower unit and from t ere
to t e lower unit's feet or spikes, forming a privileged pat to c annel vibrations away from t e unit.
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