CH L10 User manual

L10 Dual Monaural Line Preamplier
User Manual

Dear Valued Customer,
We are honored that you chose the L10 Dual Monaural Line Preamplier.
Our team has made every effort in the design and manufacture of this
top quality versatile and future-proof product and is proud to present it
to you. We hope your L10 preamplier will bring you uncountable hours
of emotional connection with your music collection.
But before you embark on your musical journey, we kindly request
your attention to the information contained in this manual. The L10, as
you will discover in the following pages, is a Swiss precision product
designed for ultimate performance and exibility. However, delivering
that ground breaking sonic and musical excellence requires your unit to
be setup and operated correctly. That is what this manual is all about.
If you have any questions or require assistance, please don’t hesitate to
contact your authorized dealer.
Once properly installed and congured, we are condent that you will
enjoy your L10 preamplier for many years.
The Concert has just begun...
Cossy F.
Heeb T.
L10 User Manual 2

Table of contents
1 Introduction
1.1 Global audio options4
1.2 Input-specic options 4
1.3 More user congurable options 4
1.4 The purpose of this manual 4
2 Setting up your L10
2.1 Safety notice 5
2.2 Unpacking 5
2.3 Package contents 6
2.4 Placing your L10, connecting the two chassis together and installing the spikes 6
2.5 Stacking the L10 (or not) 8
2.6 Connections 9
2.6.1 USB port 10
2.6.2 Ethernet port 10
2.6.3 Local area network considerations 11
2.6.4 Ground lift 11
2.6.5 Inputs 11
2.6.6 Outputs 11
2.6.7 AC Power 11
3 How to congure and operate your L10 12
3.1 Control actions in normal mode 13
33.1.1 To turn the L10 on 13
3.1.2 To select an input 13
3.1.3 To alter volume 13
3.1.4 To engage shortcuts (mute, balance, phase, etc.) 13
3.1.5 To enter menu 14
3.2 Navigating the setup menus 14
3.3 Menu options 14
3.3.1 Audio settings menu 16
3.3.2 Input-specic settings menu 16
3.3.3 Display settings menu 17
3.3.4 Shortcut menu 17
3.3.5 Network menu 18
3.3.6 Factory settings menu 19
3.4 Handheld remote control 20
3.4.1 Batteries 20
4 Firmware update
4.1 Preparing the USB stick 21
4.2 Updating the unit’s rmware 21
4.3 Emergency rmware update procedure 22
5 Troubleshooting 23
6 Specications 24
L10 User Manual 3

1 Introduction
CH products are designed and manufactured in Switzerland by CH Precision Sàrl. We use fully discrete, fully
balanced, fully complementary, ultra-short signal path circuits – but we combine them with sophisticated
software control, monitoring and protection to ensure the highest possible levels of performance, operational
consistency and versatility.
As a result, your L10 offers a number of operational features that are unique and probably unfamiliar.
For that reason it is essential that you fully understand every aspect of the L10’s operation if you are
to enjoy its maximum possible performance.
1.1 Global audio options
Mute
Absolute phase polarity
Global or local feedback
Mono mode
Balance / channel gain (up to 6dB of gain on either channel in 0.5dB steps)
Maximum starting volume / global volume limit
L10 internal stages calibration
1.2 Input-specic options
Input conguration: active, hidden or bypass
Input coupling: direct coupled or blocking capacitor
Input impedance: high (94kΩ/47kΩ) or low (600Ω/300Ω)
Input gain: ±6dB in 0.5dB steps
Input calibration
Input renaming
1.3 More user congurable options
Display: color, content and brightness
Dene shortcut functions
Network conguration
Firmware version and update
1.4 The purpose of this manual
This manual will lead you through each step of the installation and set up procedure, in a clear and logical
sequence. Although the operation and options might seem complex, they will quickly become second nature.
But because of the sheer range of options available it is easy to overlook something unless you approach set up
and conguration in a systematic way. If you take the time to follow the manual, it will ensure that you become
completely familiar with the L10’s many options and that your preamplier delivers the best possible performance.
L10 User Manual 4

2 Setting up your L10
2.1 Safety notice
Like any piece of sensitive audio electronics, there are certain precautions that you should take in handling
and installing your CH Precision L10 in order to protect yourself, your new equipment and your system.
Always handle with care. The L10 preamplier components are heavy, so have someone to help you when
unpacking, re-packing or moving them around.
Install both chassis of your L10 preamplier on strong, stable supports capable of holding their weight.
It is best to clear/prepare the supporting surfaces in advance.
Do not install your L10 preamplier near water.
Do not expose the units to any kind of liquid.
Do not install them under direct sunlight or near any heat source, such as a radiator or other apparatus
generating heat.
Do not install them in a conned space and make sure there is sufcient ventilation and airow around
and beneath each unit.
Do not operate them under high ambient temperature (>40°C) or in extremely high humidity conditions.
Only use options and accessories specied or recommended by CH Precision.
Do not open the units or try to service them yourself. Always refer to a qualied technician for service,
maintenance or upgrades. Failure to do so will void the unit’s warranty
2.2 Unpacking
The L10’s cartons are large and contain both the components and all of their accessories. You will need an
open, preferably carpeted area in which to unpack them. Please also ensure that the rack or support space
on which the L10 will be placed has been cleared and cleaned before you start. At this point it is also worth
ensuring that the connectors on any interconnect cables are cleaned and that the power to your system is
turned off. Each carton consists of an inner box and outer sleeve. It is easiest to empty one box at a time,
before reassembling it to save space.
Once you open the inner box, remove the top layer of white foam packaging. Inside you will see the
component chassis and various accessories.
With a helper, carefully lift the L10 component out of the box and place it to one side.
Then carefully remove the plastic bag in which it is sealed.
Remove the small, brown Accessory Pack and place it with its unit. Also remove the power cord and
suction cup (if present) and the four levelling/grounding spikes.
We recommend storing the Accessory Packs in a readily accessible place, so don’t put them back in the
cartons with the plastic bags when resealing them.
L10 User Manual 5

L10 User Manual 6
2.3 Package contents
Your L10 should arrive in two substantial cartons. Once unpacked these cartons and packaging materials should
be stored safely in case you ever need to transport your units. When moving or transporting the L10 units, this
should always be done in the original packaging.
The audio chassis carton should contain:
The L10 preamplier
Four composite titanium/polymer spikes
A suction cup (used to remove the four top covers)
An accessory box containing:
–an infrared remote control
– a spike adjustment screwdriver
– a Torx T-10 screwdriver
–four support discs
–four smaller, dimpled stacking caps
–a USB stick containing the latest CH Precision rmware
The power supply chassis carton should contain:
The L10 power supply with two captive umbilical cables
A power cord
Four composite titanium/polymer spikes
An accessory box containing:
–four support discs
–four smaller, dimpled stacking caps
In case of damage to either chassis, or missing components, please contact your authorized dealer immediately.
If your L10 units are still very cold from transport, please let them warm to room temperature in order to avoid
condensation developing inside them.
2.4 Placing your L10, connecting the two chassis together and installing
the spikes
Before positioning your L10 units, it is worth taking the time to make a few preliminary decisions.
Decide how many (and which) inputs you will use. Familiarizing yourself with (and making a note of)
their position on the rear of the audio chassis will be extremely useful when you come to actually make
connections and allocate/congure those inputs.
Decide whether you will use the CH Precision supplied levelling / grounding spikes. If an alternative system
is to be used, please note that the lower part of each foot that is held by three screws can be removed to
provide an easier access to the M10×1.5 central thread where a third-party system can be attached. Please
note that the CH Precision casework is designed to support weight and ground energy in the corners only. If
you choose to use third party supports they should be positioned in the same location as the unit’s original
feet and we do not recommend stacking components except using the supplied spikes and caps.
If you do plan to use the CH spikes, use the blue suction cup to liftremove the four circular covers in the top
plate of each unit. Gently insert the titanium composite spikes into each exposed shaft and use the short red
screwdriver to turn them enough to engage the threads at the bottom of each spike. Each internal thread
is coated with a thin layer of grease during assembly to prevent galling between it and the titanium spike.

L10 User Manual 7
Do not screw the spikes in too far at this point or they will protrude from the feet and potentially damage
the supporting surface. Do not replace the top-caps yet.
Check that the voltage selector on the L10 power supply unit is set to the correct local voltage and that the
power switch is off (the 0 side depressed).
Now you are ready to place the units. Each chassis is heavy and the feet are tted with rubber rings to protect
the supporting surface, which makes it hard to slide the units. Having a partner to lift and help place each
chassis will make things considerably easier.
Place the power supply rst, carefully planning the path to be taken by the two umbilicals before positioning
the unit.
Gently pull the umbilicals into position to be connected to the audio chassis, noting which is which thanks
to the color identication rings.
Move the audio unit as close as possible to the rack/support so that you can connect the umbilicals before
moving it back into position. Connect the left umbilical to the left input socket and the right umbilical to the
right input socket. The plugs on the umbilicals will only connect in one position, so turn the connector in the
socket until you feel it engage and then gently push it home until you hear a locking sound.
DO NOT force the umbilical connectors into the sockets.
This will risk damaging the connecting pins and disable your L10.
If you feel resistance when you insert the connector, check that you are trying to connect the proper pairs
of umbilicals and connectors together. Please note that the two connectors have the same diameter but
a different number of pins, so it is not possible to plug an umbilical in the wrong connector.
Each L10 chassis is supplied with a set of four support discs. These have a groove machined in the upper face
that ts over the rubber ring in the underside of each foot. Lift each corner of the chassis in turn and position
the disc beneath each foot. The groove that interfaces with the rubber ring will ensure that the footer disc
stays in place if you slide the unit.
As well as making the units easier to position, the support discs can also offer a superior interface between
the grounding spikes and the supporting surface. The spikes are designed to drain internally generated
energy away from sensitive circuitry and into a dispersive support structure, but if the supporting surface
is extremely hard or forms an impedance mismatch with the spike tips, the material and footprint of the
support discs can function as a lossy mechanical buffer, easing the passage of mechanical energy out of the
unit. As a rule, the support discs work well with very hard surfaces, but results will vary with system and
supporting surface. Once set up and warmed up, compare the sound of the unit(s) with and without the discs
in place.
Use the red screwdriver to wind down each of the four spikes until they touch the surface (or disc)
underneath. You will feel a slight resistance due to the chassis’ weight. Then turn each spike by the same
amount, for instance one more full turn. This should ensure that the load is evenly applied on all four spikes.
It is worth using a spirit level to ensure that the L10 units are perfectly level. If they are not at this point of the
setup, adjust the spikes with the screwdriver. Once this is done, simply check that all four spikes show the same
resistance to turning. This means that the spikes are rigidly coupled to the supporting discs and equally loaded.
Replace the top caps. Their magnetic coupling will hold them in place.

L10 User Manual 8
2.5 Stacking the L10 (or not)
Also included in the accessory packs is a set of small, dimpled stacking caps for each unit. These polymer
inserts allow owners to stack the L10 units on top of each other, or on other CH components. However, this will
inevitably compromise performance and should only be done when space is at an absolute premium.
The optimum support for any CH unit is to mechanically ground it to a stable, dispersive structure, either
using the supplied spikes or an after-market solution. But if lack of space absolutely mandates the stacking
of CH components, then using the supplied spikes and stacking caps will provide the best possible solution.
The stacking caps simply screw into the top of the spike wells, taking the place of the cosmetic caps.
When a second unit is stood on top of them, its spikes can be wound down into the wells in the caps,
providing a stable, safe and easily managed stacking option that improves mechanical termination
and satises aesthetic and practical considerations. Make sure that you retain the cosmetic top caps
and store them safely as you may well require them in the future if (or rather, when) your system or
circumstances change.
L10
preamplier
unit
L10 power
supply unit
magnetic
cosmetic
caps
stacking
caps
support
discs

2.6 Connections
With the two (or four) L10 units placed and levelled, you are now ready to connect your signal cables.
The rear panel layout is shown below:
L10 User Manual 9
1. RCA 1 left input
2. BNC 1 left input
3. RCA 2 left input
4. BNC 2 left input
5. XLR 1 left input
6. XLR 2 left input
7. XLR 3 left input
8. XLR 4 left input
9. XLR 1 left output
10. XLR 2 left output
11. RCA left output
12. BNC left output
13. Ethernet port for command interface
14. Ground lift: switch on to connect signal
ground (analog GND) to earth (digital GND)
15. Analog power supply socket, to be
connected to corresponding cable from
power supply unit
16. Control (digital) power supply socket, to be
connected to corresponding cable from power
supply unit
17. Signal ground (analog GND) socket
18. Chassis earth (digital GND) socket
19. USB socket for software upgrades only
20. RCA right output
21. BNC right output
22. XLR 2 right output
23. XLR 1 right output
24. XLR 4 right input
25. XLR 3 right input
26. XLR 2 right input
27. XLR 1 right input
28. RCA 2 right input
29. BNC 2 right input
30. RCA 1 right input
31. BNC 1 right input
L10 audio unit rear panel connections
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28 20 17
2
30
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27 26 25 24 23 22 19 1821
3
29
1
31

L10 User Manual 10
1. Analog power supply umbilical cable, to be
connected to the corresponding socket in the
audio unit
2. Control (digital) power supply umbilical cable, to
be connected to the corresponding socket in the
audio unit
3. Chassis earth (digital GND) socket
4. Power on/off switch
5. Fuses and voltage selector
6. Power cord socket
You will note that as well as the array of conventional inputs and outputs, there are a number of other sockets
available which are used for control and update functions.
2.6.1 USB port
The USB port is not a digital audio input. It is dedicated to upgrading the rmware of the L10. Do not use it for
any other purposes. For more information please refer to the rmware update instructions in the dedicated
chapter of this manual.
2.6.2 Ethernet port
The Ethernet port is used for two closely related functions.
Connection to a local network router will allow control of the L10, its functions and conguration through the
CH Control App, loaded on an Android device.
In True Monaural conguration (standard or extended) the connection to an Ethernet network allows the two
separate audio chassis to communicate in a Master/Client relationship, so that control settings track each other.
One unit should be set as ‘Master’ and the other as ‘Client’, in the ‘Network / Role’ menu.
In a situation where a four–chassis L10 is not connected to a network, an RJ45 Mirror lead connected
between the two audio units will allow control synchronicity. In that case, select ‘Direct-Link’ in the
‘Network / IP Settings’ menu of both audio units.
56
3 4
L10 power supply unit rear panel connections
21