Longing for detail, naturalness and imaging in digital?
Your system needs a reliable conductor.
CC2: the aordable clock you can’t aord to miss.
Please read this manual before operating the
Please read this manual before operating the unit.
unit.
Table of Contents
Table of Contents
1. Introduction 3
2. Important Safety Instructions 4
3. Installing 6
4. Signal Connections 8
5. Operation 9
6. Jitter Explained 11
7. Specications 14
8. Grimm Audio Limited Warranty 15
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Manual CC2 © Grimm Audio
1. Introduction
Thank you for selecting the Grimm Audio CC2 Central
Clock for your production environment. This product
features an ultra low jitter clock oscillator with 2 word
clock outputs. It embodies our company philosophy of
providing the most transparent signal chain possible,
enabling you to achieve the best possible results
sonically and artistically. Large parts of the CC2 circuitry,
like the oscillator and its power supplies, use a discrete
design. Because of this, a CC2 has more than 200
components. After assembly, extensive tests and an
individual jitter measurement are carried out.
• Clock stability improvement, and hence improved
sound, of digital live audio systems. By slaving your
main stage box to a CC2, the system sound quality
will likely improve.
• Improvement of your home audio system with word
clock equipped devices.
This manual describes how to set up the CC2 in your
studio, live sound or home environment as well as
important tips on how to get the best performance from
the CC2. In addition, some background information on
the unit’s operation is provided.
1. Introduction
The CC2 can be used in a wide variety of applications
such as:
• House Sync generation in audio studios. Two
outputs oer enough exibility for most modern
setups. The extremely low jitter of the CC2 clock
outputs maximises the sound recording and
playback quality potential of the devices connected.
We hope this investment will bring you many years of
creative enjoyment and help you achieve your goals.
Manual CC2 © Grimm Audio
3
2. Important Safety Instructions
2. Important Safety Instructions
Please follow these precautions when using
this product:
Grimm Audio gaat er van uit dat u deze Engelstalige tekst
volledig begrijpt. Als u hier moeite mee heeft dient u contact
op te nemen met Grimm Audio. Op verzoek sturen wij u een
vertaling toe.
1. Read these instructions.
2. Keep these instructions.
Grimm Audio nimmt an, dass Sie diesen Englischen Text
völlig verstehen. Wenn notwendig, nehmen Sie bitte Kontakt
auf mit Grimm Audio. Auf Wünsch wird Ihnen eine
Übersetzung zugeschickt.
Grimm Audio suppose que le lecteur comprend
parfaitement le texte en Anglais ci-dessous. En cas de doute
s.v.p. contacter Grimm Audio. Si necessaire, on pourra vous
envoyer une traduction.
Grimm Audio da por supuesto que el texto en versión
Inglesa no ofrece ninguna duda de interpretación y se
entiende integramente. Si este no fuese su caso rogamos
contacte con Grimm Audio quien, a petición, se encargaría
de enviarle la correspondiente traducción.
4
Manual CC2 © Grimm Audio
3. Heed all warnings.
4. Follow all instructions.
5. Dangerous voltage is inside this apparatus. Opening
is only allowed by qualied service personnel.
6. Verify line voltage before use.
7. Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two
blades with one wider than the other. A groundingtype plug has two blades and a third grounding
prong. The wide blade or the third prong are
provided for your safety. When the provided plug
does not t into your outlet, consult an electrician
for replacement of the obsolete outlet.
liquid cleaner onto the faceplate, as this may
damage the front panel.
2. Important Safety Instructions
8. Protect the power cord from being walked on or
pinched, particularly at plugs, convenience
receptables, and the point where they exit from the
apparatus.
9. Unplug this apparatus during lightning storms or
when unused for long periods of time.
10. Do not use this apparatus near water.
11. Do not use this apparatus outside.
12. Do not expose the apparatus to dripping or
splashing. Do not place objects lled with liquids
(ower vases, drink cans, coee cups, etc) on the
apparatus.
13. Clean only with a dry, soft, non-uy cloth. Do not
spray any liquid cleaner onto the cabinet, as this
may lead to dangerous shocks. Do not spray any
14. Install in accordance with the manufacturer’s
instructions.
15. Do not install near any heat sources such as
radiators, heat registers, stoves, or other apparatus
(including ampliers) that produce heat. Avoid
exposure to direct sunlight.
16. Use only attachments or accessories specied by
the manufacturer.
17. Use only with a cart, stand, bracket, or table
designed for use with professional audio or music
equipment. In any installation, make sure that injury
or damage will not result from cables pulling on the
apparatus and its mounting. If a cart is used, use
precaution when moving the cart/apparatus
combination to avoid injury from tip-over.
Manual CC2 © Grimm Audio
5
3. Installing
18. This unit runs slightly warm when operated
normally. Operate in a normal ventilated area. If
this product will be installed in a rack, make certain
there is sucient air movement within the rack.
19. Refer all servicing to qualied service personnel.
Servicing is required when the apparatus has been
damaged in any way, such as when the powersupply cord or plug is damaged, liquid has been
spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture,
does not operate normally, or has been dropped.
3. Installing
Unpacking and Inspection
Your CC2 was carefully packed at the factory and the
packaging it came in was designed to protect it from the
trials and tribulations of shipping. Keep the box and all
packing materials, so that in the unlikely event that you
need to return the CC2 for servicing, you can do so
safely.
Mounting the CC2
20. WARNING: To reduce the risk of re or electric
shock, do not expose this apparatus to rain or
moisture.
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Manual CC2 © Grimm Audio
The CC2 is available in two versions:
• a small and compact unit for stand alone use.
• a standard rack unit with 19” front.
The CC2 does not produce strong RF elds nor is
susceptible to them. You can position it near other
digital gear such as computers and disk recorders
without worry. In general it is a good idea to keep some
distance between monitors (LCD and CRT) and audio
cables because of risk of induced low level noise due to
stray magnetic elds.
Grimm Audio products have a real wooden face plate
that provides a beautiful and vivid appearance. The CC2
front panel is made of Padouk. The panel is nished
with an environmentally friendly oil. To maintain the
outstanding looks, one is advised to take some
precautions:
• Do not place the CC2 in very dry environments.
• Do not use chemical or alcohol based cleaner on
the wood.
• Avoid exposure to direct sun light, since the padouk
wood is susceptible to discolor in UV light.
AC Power Hookup
The CC2 has a linear power supply that needs to be
factory set for your local line voltage (115V or 230V +/-
10%). Make sure to check the line voltage at the back
near the IEC cable entrance (‘wired for ... V’) and verify if
this complies with your local mains voltage. The CC2 is
shipped with a proper mains cable. Grimm Audio
cannot be held responsible for problems caused by
using the CC2 with improper AC wiring or voltage.
The CC2 does not have a power switch on the front
panel; a convenient way to power down the unit is to
use a power strip equipped with a switch or eventually
power it down with the mains switch at the back.
3. Installing
Manual CC2 © Grimm Audio
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Grimm Audio | CC2
Central Clock Source
1
2
Handcrafted in the Netherlands
Serial # 12-0.001.xxx
WARNING
This apparatus
must beearthed
Wired for
230V
115V
Word Clock Out
75Ω
1 2
Impedance
low
CAUTION
Risk of
electric shock
Do notopen
4. Signal Connections
4. Signal Connections
Multiplication factor
Base rate
BNC Outputs
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Manual CC2 © Grimm Audio
Impedance
(75 Ohm or Lo-Z)
Mains power
connection
5. Operation
Output impedance
5. Operation
The CC2 is a high performance master clock, it has no
slave option. Switches on the front and back oer
adjustments to the needs of your system and project.
On the front
• The bottom (horizontal) toggle switch selects a 44.1
or 48 kHz base rate.
• The top (vertical) toggle switch has three positions
and sets the multiplication factor of the base rate to
1, 2 or 4.
These switches control both BNC outputs
simultaneously. LEDs on the front indicate the current
sample rate setting.
On the back
Two miiniature switches select between 75 Ohm or Low
output impedance per BNC output.
Word sync connections are usually 5V square waves
transmitted using 75 ohm (video) coax cables. Although
the word clock frequency itself is relatively low, the
transitions are steep. Taken as a whole, word sync is a
wideband signal, usually necessitating characteristic
termination at least at one end of the cable. Better still
is series termination on the transmit end and parallel
termination on the receiving end. This minimises
reections even when the cable impedance is not
exactly matched.
Double termination like this produces a 6dB loss,
resulting in an eective 2.7V signal. All Grimm Audio
products are designed to work in this manner.
Unfortunately there is no standard dened for word
sync connections. As a result, implementations vary
across various makes. Outputs may be series
terminated or low impedance, DC or AC coupled. Inputs
may be parallel terminated or high impedance. This
yields to 8 permutations, all of them encountered in the
eld. To make things worse, we have reports from
Manual CC2 © Grimm Audio
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5. Operation
customers that in some cases devices do lock to a word
clock signal when terminated, but their sound quality is
improved when unterminated. So our advice is to
experiment with it yourself on your own device.
The output impedance of the CC2’s may need to be set
“low” in some cases. For instance, a parallel-terminated
input expecting a 4V input signal will only work with the
CC2’s output impedance set low. A fair number of
products were found to have parallel terminated input
but stop working around 2.5V which is why the CC2 puts
out a slightly higher-than-normal voltage in order to
allow correct operation in the factory preset mode.
Nevertheless, some equipment will only respond
correctly when the output impedance switch is set to
low.
Connection
The CC2 has two word clock outputs. Each device
connected to the CC2 should be set to slave to word
clock. The preferred system wiring is ‘star distribution’
where each output of the CC2 connects to one device.
Daisy chain connections using T-junctions should be
avoided where possible. The latter will most likely fail
because of the lack of standardisation of termination
impedance and signal levels. In case you need more
word clock outputs, consider to buy our CC1 clock
distributor, which has 16 outputs.
Use 75 ohm coaxial cables with a low transfer
impedance. Since word clock is an unbalanced
connection, noise currents generated by earth loops will
ow through the BNC cables and any series impedance
in the connection can cause interference. The CC2 has a
low-impedance reference plane at the rear, insuring that
it will never be aected by circulating currents. By all
means, never defeat the safety earth connection of any
device that is designed to have an earth connection.
Lifting grounds may produce a lethal shock hazard and
will likely lead to unwanted high currents through coax
shields.
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Manual CC2 © Grimm Audio
Hints
6. Jitter Explained
6. Jitter Explained
• Select decent quality 75 Ohm coax cables and
certainly do not skimp on the quality of the
connectors.
• Make cables no longer than necessary.
• Cables add propagation delay. It is exceedingly rare
for dierences in clock phase to aect the
interoperability of connected audio equipment, but
if it happens, using equal length cables throughout
helps.
• Disconnect unused cables.
Jitter is an instability in the timing of a clock signal.
Ideally the rising or falling edges of a clock signal are all
separated by exactly the same amount of time. In
reality, the timing is more uncertain. The graph below
shows the time-domain view of the problem.
A stable and a jittery clock signal
We can also look at the problem spectrally. An ideal
clock has only a single frequency components (and
harmonics). All energy is concentrated on an innitely
narrow frequency band, see the top picture below.
When jitter is present, side bands occur. Some spectral
energy is located away from the clock. The faster the
Manual CC2 © Grimm Audio
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6. Jitter Explained
timing chatters, the further away from the main
frequency you’ll nd energy.
The red curve in the bottom graph shows only random
jitter. Sometimes jitter is periodical and then you
wouldn’t see a smooth slope but sharp peaks. An
important note is that frequency accuracy has
absolutely nothing to do with jitter at all. The red graph
shows a jittery clock with an exactly correct frequency,
say 44100.0000000Hz, the blue one shows a clock that’s
Amplitude
somewhat o but otherwise brilliantly stable. A
frequency error can be annoying from a practical
perspective, but as far as signal quality is concerned
frequency
you’re better o with a stable clock at an inexact
frequency.
12
Jittery clock
Amplitude
Spectra of clock signals
Manual CC2 © Grimm Audio
Jitter-free clock,
slightly off th e
ideal frequency
frequency
Jitter is not a problem in fully digital processes. As long
as it isn’t so large that a processor can’t distinguish the
previous bit from the next, all-digital processes are
completely indierent about jitter. The problem occurs
when you go from the analogue domain into the digital
domain or back. Digital audio presumes uniform
sampling. That way, given a string of numbers and
knowledge of the sampling interval, you can perfectly
reconstruct a sampled signal. With jitter that theory falls
apart.
Jitter in AD (top) and DA (bottom) converters
Imagine the signal on top. The AD converter samples it
at neatly uniform intervals. The DA converter
reconstructs the correct values but it gets the timing
wrong. The dierence between the red and blue curve
shows the error. Or take the converse: the DAC is ne
but the ADC took samples at the wrong time. The eect
is much the same. What’s worse in this case is that the
numbers we’ve recorded are now wrong. In the previous
case we could slap in a better DAC, with a jittery ADC the
game is over.
6. Jitter Explained
Manual CC2 © Grimm Audio
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7. Specifications
7. Specications
• Output impedance 75 Ohm or 25 Ohm (‘low’),
switchable via micro-switches on the back.
• Life expectancy power supply electrolytics >
45.000hr
• Power supply voltage range +/- 20%
14
• DC coupled output.
• Output voltage 75 ohm mode:
▪ 75 ohm terminated: 2.7 Vpp
▪ unterminated: 5.5 Vpp
• Output voltage 25 ohm mode:
▪ 75 ohm terminated: 4 Vpp
▪ unterminated: 5.5 Vpp
• Internal intrinsic clock jitter <0.6 ps RMS (> 10 Hz).
• Clock frequency master mode: 44.1 or 48 kHz ± 25
PPM, -5 +50 °C.
• Maximum ambient temperature for operation: 50
°C.
Manual CC2 © Grimm Audio
• Fuses:
▪ 115V: fuse 100mA slow blow
▪ 230V: fuse 50mA slow blow
• Weight: 1,7 kg
• Dimensions: 400 x 40 x 160 mm.
• Power consumption: 5 W.
• Wood type of front: Padouk.
8. Grimm Audio Limited Warranty
Grimm Audio BV (“Grimm Audio”) warrants this product
to be free of defects in material and workmanship for a
period of two (2) years for parts and for a period of two
(2) years for labor from the date of original purchase.
This warranty is linked to the serial number of the
device and can be transferred to second hand owners if
they can show their purchase bill. The original owner
can extend his limited warranty to a period of ve (5)
years for labor and parts if he sends the original
warranty card that came with the unit to the Grimm
Audio factory. The extended warranty is enforcable only
by the original retail purchaser and cannot be
transferred or assigned.
During the warranty period Grimm Audio shall, at its
sole and absolute option, either repair or replace free of
charge any product that proves to be defective on
inspection by Grimm Audio or its authorized service
representative. In all cases disputes concerning this
warranty shall be resolved as prescribed by law. To
obtain warranty service, the purchaser must rst call or
write Grimm Audio at the address and telephone
number printed below to obtain instructions where to
send the unit for service. All enquiries must be
accompanied by a description of the problem. All
authorized returns must be sent to Grimm Audio or an
authorized Grimm Audio repair facility postage prepaid,
insured and properly packaged. Proof of purchase must
be presented in the form of a bill of sale or some other
positive proof that the product is within the warranty
period. Grimm Audio reserves the right to update any
unit returned for repair. Grimm Audio reserves the right
to change or improve design of the product at any time
without prior notice.
This warranty does not cover claims for damage due to
abuse, neglect, alteration or attempted repair by
unauthorized personnel, and is limited to failures
arising during normal use that are due to defects in
material or workmanship in the product.
In no event will Grimm Audio be liable for incidental,
consequential, indirect or other damages resulting from
the breach of any express or implied warranty,
8. Grimm Audio Limited Warranty
Manual CC2 © Grimm Audio
15
8. Grimm Audio Limited Warranty
including, among other things, damage to property,
damage based on inconvenience or on loss of use of the
product, and, to the extent permitted by law, damages
for personal injury.
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Manual CC2 © Grimm Audio
© 2019, Grimm Audio BV. All rights reserved
Reproduction in whole or in part is prohibited.
Specications subject to change without notice.
Grimm Audio CC2 manual v1.1, 12/02/19
Manual CC2 © Grimm Audio
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Grimm Audio BV
Egelstraat 2
5622 AK Eindhoven
The Netherlands
+31 40 213 1562
info@grimmaudio.com
www.grimmaudio.com
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