Netherlands Grimm Green CC1 mk2 research-grade mastering audio clock Guangzhou audition

GRIMM AUDIO CC1 MKII MASTER CLOCK

CC1 is equipped with a self-developed PLL phase-locked loop with excellent performance. The new generation CC1 provides an amazing 90dB jitter suppression at 10Hz, and then further improves to 150dB at 100Hz. In addition to providing 2 sets of 44.1kHz, 48kHz and 1/2/4 multiplier basic audio frequencies at the same time, CC1 can also be used as an AES/EBU reclocker, providing noise shaping function to remove jitter for digital signals of DA converters .

2018 version of the front panel（front）is light wood, rear panel（butt）silver aluminum alloy plate

Grimm CC1 contains precise master clock specifications: 0.6ps @10Hz

CC1 also has a special "wash" function for AES/EBU input and output. Phase Locked Loop of CC1（Phase Lock Loop, PLL）Capable of attenuating 90dB clock jitter bias down to 10Hz（jitter）! From 10Hz to 100Hz, CC1 can further enhance the jitter removal capability of 60dB, that is, attenuate 150dB of jitter at 100Hz!

The CD format has a bit depth of 16 bits, each 1 bit is equal to 6dB of dynamic range, and the CD format has a maximum dynamic range of 96dB, that is to say, if all the signals in the CD have jitter, in the 10Hz field, CC1 is close to clearing all jitter!

In theory, 24bit recording can store up to 144dB dynamic range, and CC1 can clear 150dB jitter at 100Hz! It means that no matter how many jitters are in the recording, under the cleaning of CC1, there is almost no jitter in the digital signal output to the DAC!

The design was determined by the world-renowned Delft University of Technology''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s Audio Technology Laboratory. Of the top five mastering studios in the world in 2017, three are using CC1 as their master clock. known in the professional field“House Sync”.

The performance of CC1 is beyond the conclusion that the general civilian HiFi eye sees at a price. He has absolute strength compared with master clocks of any price on the market.

CC1 has 2 groups of frequency multiplier circuits to provide independent main clock output, which can synchronize 2 groups of devices with different sampling rates. For example, at the same time, the first group output 44.1kHz, the second group can output 44.1kHz base frequency x2 (88.2kHz); or, the first group output 96kHz, the second group can output 48kHz base frequency x4 (192kHz). Therefore, CC1 can also perform simultaneous oversampling of AES/EBU signals（SSRC）For example, in Master mode, the AES/EBU input is connected to the 44.1kHz digital signal of the CD player, the base frequency of 44.1kHz is selected on CC1, and the second group of multipliers is selected to x4, that is, the sampling rate of 176.4kHz, then the AES/EBU output is increased It is a 176.4kHz digital signal. CC1 cannot output 44.1kHz and 48kHz base frequency at the same time

Evaluation:

Before reading the introduction I wrote, I ask you to help me do an action to see if there is a Clock in or Clock Sync interface on the back of your digital equipment, or if you are using a split turntable and DAC Combination, if yes, then I would like to congratulate you first, because the equipment to be introduced this time can definitely greatly improve the sound performance of your digital source. The protagonist is the Grimm Audio CC1 master clock from the Netherlands. Founded in 2004, Grimm Audio has assembled a group of top sound electronics, acoustics, and physicists to jointly develop and develop. They are also audiophiles who love music.

The core people of Grimm Audio: Eelco Grimm

Grimm Audio''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s first product, the AD1 Momentum 1-bit Analog-to-Digital Converter, is still the benchmark for quality in the industry, and is still used by major classical music companies such as Channel Classics.

Based on the success of AD1, Grimm Audio has evolved its clock circuit and released the CC1 master clock, which is the master clock with the lowest time base error in the professional market. Three of the world''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s top five mastering studios, Mastering Lab, are using CC1 as the digital master clock. , known in the professional field as“House Sync”.

CC1 has a total of 16 clock signal outputs, which are divided into two groups, 1~12 are Group 1, and 13~16 are Group 2. The impedance of each clock output can be individually set to 75 ohms or Low (25 ohms). The factory default and most cases use 75 ohms. Each output of Group 2 also has a 0-degree or 180-degree phase adjustment function. For home audio, impedance and phase adjustment are unlikely to be used. The original manufacturer mentioned in the manual, In a few cases, if you find that the signal cannot be locked, you can try switching the impedance.

Master Mode: Use CC1 as the master clock
For home audio users, one of the main ones is to use the Master Mode of CC1. In Master Mode, you can select the reference frequency of the clock output to be 44.1kHz or 48kHz, and press the "Source" button to switch. This setting depends on the sampling frequency of the music being played. It must be a multiple of it. For example, if the CD specification is 44.1kHz, then it should be set at 44.1kHz. If I am playing a 24Bit/96kHz music file today, then To be set at 48kHz (48×2=96), if playing SACD or DSD files, it should be set at 44.1kHz. The I on the right represents the output multiple setting of Group 1 (1~12), and II represents the output multiple setting of Group 2 (13~16). The multiple setting of the two groups can be different.

From here, it can also be found that Master Mode may have a relatively inconvenient place. If I change from CD to listening to SACD discs, I have to manually switch from 44.1kHz to 48kHz, or listen to music files, the sampling of each song If the frequency reference is different, you should also switch it. CC1 will not automatically change for the music source. If the sampling frequency of the music you listen to is often different, you can consider setting CC1 to"Slave Mode", input the most source signal source to CC1 with AES, and then output CC1 to DAC, the sampling frequency of CC1 will automatically switch with the source, but because each switch is re-locked, it will take more time, such as The connection method also uses AES3 Reclocking of CC1"wash water"function, the digital signal of the turntable is removed by CC1 to remove the time base error and then output to the DAC.That is to say, if the turntable and DAC have no clock input to synchronize, using CC1 Reclocking can still improve the sound performance.When using the Reclocking function, remember to set the AES to "thru". If the equipment does not have an AES digital interface, it can also be changed to RCA through the adapter, and the effect is the same.

In any digital system, there can only be one master clock. The master clock must be at the source of the source.The connection method on the left and in the picture is possible, but the connection method on the left is more recommended, that is, each device is connected to the main clock of CC1, and the DAC in Figure 3 receives the clock of the turntable and CC1 at the same time, which will cause an error.

The master clock of Master Mode in the figure below is CC1, and the master clock of Slave Mode is the most source dial.

Where is the Grimm Audio CC1 master clock strong?
The front is the introduction of the use of the clock. In short, if the equipment can be connected to an external clock, it can be directly connected to CC1. If the equipment cannot be connected to an external clock, CC1 can also be used to wash water (Reclocking) through the AES digital interface, then it is more important. The question is, can CC1 really get better? The official website provides many very in-depth technical and theoretical documents. To fully understand it not only takes time, but also has a relevant background. I can only roughly try to summarize the key concepts. Let’s first look at the official CC1. Effect introduction, when CC1 is used to synchronize the master clock, the time base error (Jitter, or jitter) can be suppressed by 90dB at 10Hz, and at 100Hz, it can be suppressed by 60dB more, reaching 150dB, and the dynamic range of 16Bit CD is 96dB, the dynamic range of the 24Bit music file is 144dB, and the CC1 is enough to suppress the generation of jitter.

The picture below shows a well-known Digital Audio Workstation (DAW). It can be seen that when CC1 is used as the master clock below 200Hz, Jitter has been suppressed.

Generally, when we judge the performance of a clock, we will directly look at its accuracy (Accuracy). per million), there are 24 hours x 60 minutes x 60 seconds = 86,400 seconds in a day, so the daily error will be 86,400/1,000,000 = 0.0864 seconds. The recently popular Rubidium Atomic oscillator has an accuracy of 0.001 ppb (parts per billion, one billionth), and the daily error is only one thousandth of that of TCXO, 0.0000864 seconds. Does the audio system need to use such a precise clock? Apart from accuracy, are there any other variables that affect the sound?

Grimm gives an example in his white paper how does a 10 ppm error sound? The speed of sound is 340 meters per second, and every 1 degree increase in speed increases the speed by 0.607 meters, which is an increase of 0.17%, now if the recording time is faster or slower 10 ppm is equal to 0.0034 meters faster or slower, which is equivalent to a temperature increase or decrease of 0.0056 degrees (= 0.0034/0.607), so if someone says he can hear a 10 ppm difference, it''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s like he can hear when the room The difference in sound with a temperature change of 0.0056 degrees, empirically speaking, a trained human ear can hear a difference of 700 ppm at most. The Red Book’s requirement for CD turntables is about 200 ppm, and the CC1’s accuracy is 2 ppm. That''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s enough, and a more accurate clock doesn''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t seem to be that important to sound, Grimm points out, in addition to being accurate,The stability of the clock is also very important, the stable clock will be smaller than the unstable clock Jitter. On the other hand, the rubidium atomic clock was not originally used in sound, but in the laboratory. Therefore, the products available on the market are all based on the laboratory''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s 10MHz standard, which is why the audio is only 10MHz. The frequency is completely irrelevant (44.1kHz or a multiple of 48kHz), so it needs to be converted into the required frequency through a synthesizer. Such tough processing is not helpful for Jitter elimination. Use a good quartz oscillator to correspond to the desired frequency. The frequency required is the best. CC1 users do not need to deliberately connect the rubidium atomic clock.

Why is the clock improved but not obvious?
I rarely see such an honest manufacturer. Generally, the manufacturers of High End audio equipment will say that their products are the best, or the sound will be significantly improved, but Grimm seems to have forgotten that he is a manufacturer and wrote two very special articles. Technical white paper to explain why sometimes the effect is not obvious when the rear equipment is connected to an external clock? The key lies in the setting of PLL phase-locked loops (Phase-locked loops). The PLL is the circuit used by the equipment to synchronize with the external clock. If its setting response is very slow and the bandwidth is narrow, the influence of the external clock will be very large. On the contrary, if it is very fast and the bandwidth is wide, the effect of the external clock will be obvious. Some manufacturers are very confident in their equipment, so the PLL is set to be slow, but at the same time, it also isolates most of the improvement of the external clock. Possibly, the external clocks of most devices can still be significantly improved.

Actual listening: The sound is noticeably improved
I use CC1 as the master clock first, and input the clock signal to Esoteric K-03X for synchronization. The high-precision VCXO voltage-controlled crystal oscillator (voltage-controlled crystal oscillator, with an accuracy of 0.5 ppm) has been used inside. I already feel that the sound has improved a little. After reheating the machine for about 20 minutes, the sound performance is like being reborn. , the image is more clear, if you change to the internal clock of the CD turntable, the whole is loose and the noise will increase. CC1 has x1, x2, x4 output frequency multiplier settings, take 44.1 as an example, corresponding to 44.1, 88, 2 and 176.4 respectively, you can switch directly when listening, but the CD turntable music is interrupted, and you have to wait for the new frequency to lock again. I have repeatedly compared the difference between 1x and 4x. The sound direction has not changed, and the difference is not very big. The main reason is that at 1x, that is, maintaining 44.1kHz, it sounds more natural and smooth, while 4x is 176.4kHz. Stronger, the setting of the multiple is not fixed, it is mainly adjusted according to the record, the system and your own preferences.

AES3 Reclocking "Washing" function is effective
In order to try the washing function of CC1, I removed the clock cable that originally connected the K-03x to CC1, and switched the AES digital output to CC1, and then CC1 output the AES signal to the WEISS 502 for decoding output. At this time, CC1 needs to be set In Slave Mode, the rear AES should be set to "thru". Compared with the direct K-03x AES output to the WEISS 502, after CC1 Reclocking to eliminate the jitter, the texture becomes better, the burrs become less, and the sound is cleaner, which is effective. Yes, but compared with K-03x using CC1 as the external main clock, the effect of the clock is still much more obvious. As mentioned earlier, Reclocking can be used by people whose sources do not support an external clock function.

So can CC1 be used as the external main clock of K-03X and perform reclocking at the same time? The answer is yes, set CC1 back to Master Mode, 44.1kHz, and then output the same K-03X to CC1 and then output to WEISS DAC502. Compared with no CC1 Reclocking, the sound seems to be cleaner.It should be noted that as long as the CC1 AES Reclocking function is used, it cannot support DSD.

When using CC1, the original factory has some tips to pay attention to:
●   Use good quality 75 ohm coaxial cable, and pay attention to the quality of the terminals.
● The length of the line is just right, not too long.
● The cable will have a delay effect (Propagation Delay), try to use the same length of the cable.
● Turn off unused equipment and do not connect it.
● When CC1 is the main clock, don''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t connect the clock input, there will be crosstalk (crosstalk), the same is true for AES3, don''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t connect it when it is not in use.

The usage of CC1 is very many, and the clock output is also very large. If you just want to enjoy the pure main clock function, you can consider the CC2 of the smaller platform. According to the agent, the performance of the two in the clock part is almost the same, the difference is the CC2 There are only two sets of clock outputs, and the CC2 doesn''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t have AES Reclocking either.

All in all, if the CC1 can be removed, there is only one reason, that is, there are not enough children in the pocket.… a thousand words can''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t compare to the personal experience. It is strongly recommended for interested friends to experience it. This will be a device that will "I poison everyone, everyone poisons me"!

Grimm Audio CC1 Master Clock Focus
● Very low time base error (Jitter)
● 16 groups of clock output, impedance can be set individually.
● AES Reclocking function
● Sampling frequency from 44.1kHz~192kHz.
● The multiples can be set separately for the two groups of sampling frequency. (1x, 2x, 4x)
● The output phase of the second group can be adjusted individually.
● Sound Features: Overall improvements have been made.
● Matching suggestion: None, please be sure to experience the effect for yourself, you will know after a try.