The Cen.Grand 9i-906 was kindly provided as a long term loan in exchange for an honest review. I didn’t receive monetary or any other kind of compensation and I don’t use affiliate links. The price of the Cen.Grand 9i-906 is $4190 and you can buy it from Power Holdings or any other authorized dealers around the world.
Cen.Grand
Cen.Grand, a Chinese high-end audio manufacturer, was established in 2011 by a team of experienced audio engineers. While this brand may not be well-known in Western markets, it has gained significant popularity in China, where it was once among the largest manufacturers of HiFi Blu-ray players. Cen.Grand’s focus extends beyond audio alone, as they strongly believe in offering products that incorporate cutting-edge technology in both audio and video. Their product range currently includes a variety of audio devices such as DACs, headphone amplifiers, and digital media players. Notably, some of their products, like the DSDAC 1.0, a top-tier DAC utilizing DSD audio technology, have already earned a strong international reputation. Additionally, Cen.Grand is set to launch the GLD1.0, a media player featuring disruptive technology, in the near future.
You can read everything about the Cen.Grand history here.
Cen.Grand 9i-906 “Silver Fox” headphone amplifier
Cen.Grand currently offers four models of headphone amplifiers, with the 9i-906 “Silver Fox” standing out as their top-of-the-line option. This powerful headphone amplifier is capable of delivering 20W into 30Ω loads, providing more than enough power to drive any type of headphone on the market.
The circuit design of the 9i-906 headphone amplifier is inspired by high-end power amplifiers. It features eight Exicon lateral MOSFETs in the power amplifier stage, with four per channel or two per phase. These MOSFETs are strategically placed on the bottom of a thick aluminum chassis, which acts as a superior heatsink, effectively dissipating thermal loads. The input stage utilizes one MUSES02 op-amp per channel, renowned for its analog-like and organic sound. The linear power supply features a custom-made 120W toroidal transformer with separate windings for critical circuit stages. Each channel has its own power rail, and there are several local regulated supplies with a total of 31200μF of rectifying capacitance. Nichicon and Wima capacitors, along with the MUSES72320 volume control chip, contribute to the amplifier’s exceptional performance. Only high-quality components from reputable brands are used, with premium cabling for internal connections.
Build quality and appearance
The Cen.Grand 9i-906 is as sturdy as a tank, with a chassis crafted from thick, CNC machined aluminum alloy that has a sleek and high quality finish. Acting as a large heatsink, the massive aluminum chassis also shields the internal board from external EMI. The transformer is housed in a separate compartment to reduce mechanical hum and EMI radiation. Available in silver and black, this amplifier weighs a hefty 12kg and comes with high-quality, anti-vibration feet already installed.
This amplifier stands out from the crowd with its unique design features. The side walls feature a striking pattern of venting grills, while the slightly angled top center of the front panel showcases an engraved logo that reads “music is my soul”. Two vertically engraved lines divide the front panel into three sections, with the center one housing the LCD screen for displaying operational information.
Connectivity
The Cen.Grand 9i-906 is equipped with four different types of headphone output interfaces: 4-pin XLR balanced, 6.35mm single ended, 4.4mm balanced, and double 3-pin XLR balanced. Despite having multiple headphone output interfaces, they are all connected in parallel. Therefore, it is advisable to use only one pair of headphones at a time in order to achieve the best sound quality.
At the rear of the unit, there are two balanced XLR inputs and two unbalanced RCA inputs. These inputs can be used simultaneously, and you can easily select the desired input by using the source button on the front panel. Even if you input an unbalanced signal, the internal circuitry will convert it into a balanced signal, ensuring that you still receive the maximum output power.
However, it is worth noting that the conversion from single ended to balanced may slightly impact the sound quality. Therefore, if your source has a balanced output, it is recommended to prioritize using the balanced signal input. Nevertheless, if your source only has a single ended output, it is not a problem to use the single ended input.
Operation
The 9i-906 functions solely as a headphone amplifier and is user-friendly. It features just three operation buttons: power standby, input selection, and high/low resistance mode selection. To switch between high and low resistance modes, hold down the resistance mode button. The unit offers four modes: high resistance, low resistance 1, 2, and 3. Press the same button briefly to choose one of the four output modes: Normal, Balanced (BTL), Virtual Ground (Active G), and Parallel. Your selections will be shown on the screen. Additionally, a master on/off switch is located on the back of the device.
The Volume control
The volume control knob, located on the right side of the front panel, allows you to adjust the volume with precision. This electronic volume control offers 1dB increments within a range from -70dB to 5dB. It is designed for smooth operation with tactile feedback, but adjustments should be made slowly to achieve the desired 1dB increments. The unit is equipped with a built-in protection function to prevent sudden volume increases. If the volume reaches the maximum level unexpectedly, the protection will automatically activate, reducing the volume to -20dB. Please note that this unit does not support remote control functionality.
The four output modes
The 9i-906 is compatible with four output modes: Normal, Balanced (BTL), Virtual Ground (Active G), and Parallel. Each mode utilizes a unique signal path and grounding method during amplification, resulting in distinct sound characteristics and varying output currents. For additional details, please consult the accompanying diagram.
When equipped with a balanced connector, the headphone allows for activation of all four modes. However, if a single-ended connector is used, only Normal and Parallel modes can be activated. Opting for BTL and Active G in this scenario essentially functions as if the normal mode is being utilized.
The output impedance modes
The amplifier is also compatible with three low resistance and one high resistance modes, allowing for a wide range of headphones to be used. Each mode will essentially adjust the output impedance of the amplifier, although the naming convention may be somewhat confusing.
The high resistance mode features an output impedance of less than 1Ω. It is considered the purest and most optimal output mode for use with all headphones, provided that there is no background noise or sudden volume increase.
The low resistance modes effectively increase the output impedance of the amplifier. The first mode has an output impedance of 50Ω, the second mode 100Ω, and the third mode 150Ω. You can utilize any of these settings to reduce background noise when using highly sensitive headphones.
Nevertheless, there is a drawback associated with this approach as opposed to using a standard high/low gain system. The high output impedance values can pose a problem since sensitive headphones typically have low impedance. This can lead to an impedance and damping factor mismatch that might impact the headphone’s frequency response, particularly in the lower frequency range. While this method may be suitable for planar magnetic headphones, which are not affected by the headphone amplifier’s output impedance, it can create problems with the majority of dynamic headphones.
I suggest utilizing the high resistance mode as a default, unless you encounter excessive background noise or are unable to adjust the volume effectively. In those situations, I recommend sticking with the high resistance mode and using a device such as the iFi iEMatch, which can address the mentioned problems without increasing the output impedance.
Power output and headphones matching
The Cen.Grand boasts an impressive level of power, capable of effortlessly handling any headphone on the market. It excels at driving even the most challenging headphones, such as the HIFIMAN Susvara, delivering exceptional performance with dynamic swings and ample headroom. I rarely found the need to exceed 1⁄4 of the maximum volume. Other headphones were a breeze to drive. When using headphones like the Meze Elite, the HIFIMAN HE1000SE, the HEDDphone 2, and the Focal Clear Mg, I utilized the high impedance mode without encountering any background noise, while still having a wide range of volume adjustment. The amplifier remains virtually silent with most loads, except for extremely sensitive earphones, which are not typically used with the 9i-906. In terms of thermal performance, the 9i-906 remains only slightly warm even under demanding conditions.
I have also experimented with the three low resistance output modes, but I found the results to be somewhat disappointing. When using most low impedance headphones, the bass became overly bloated and less distinct compared to the standard setting. Nevertheless, certain headphones, such as the Sennheiser HD8XX or the Sennheiser HD660S2, actually sounded better with the higher output impedance of the low 1 resistance mode than with the high resistance mode. It is evident that there are numerous possibilities for achieving optimal headphone matching, and users are advised to explore different options to find the most suitable one.
Associated gear
As usual, the 9i-906 was subjected to a 150-hour music playback session before the evaluation. I relied on the Lab12 dac1 reference in a special edition with upgraded capacitors and Gold Lion 6922 output tubes as my main source during the assessment. The Lab12 Gordian multifunctional power distributor/conditioner conditioned the mains, and Lavricables provided all headphone cables.
Listening impressions
The Cen.Grand 9i-906 embodies grandeur, authority, and assurance, encapsulating the essence of a high-end audio experience. With a blend of technical excellence, refined textures, extended frequency response, balanced tonality, linear performance, precise sound reproduction, transparent presentation, and realistic timbre, this headphone amplifier stands out as a masterpiece in the world of audio equipment.
The 9i-906 delivers a perfectly balanced sound, ranging from deep lows to a musical mid-range and up to a vivid yet smooth treble. Every component has been meticulously selected to shape the sound signature, ensuring that nothing is missing and nothing is excessive. It is evident that the amplifier was fine-tuned by the ear, with the designer dedicating countless hours to achieve a sound quality that meets both a surplus of musicality and modern measuring standards.
This amplifier offers exceptional transparency and accuracy, faithfully reproducing the input source with a mirror-like fidelity. It also delivers a musical and engaging sound, emphasizing timbre realism. The Silver Fox is highly resolving, capable of extracting even the most subtle nuances from the music in a natural manner that avoids sounding analytical or sterile.
More listening impressions
The technical aspects are top-notch and truly remarkable. It would be redundant to elaborate on the impactful and dynamic bass, which shows exceptional tightness, control, and just the right amount of speed and decay reverb for a completely realistic sound. Similarly, there’s no need to delve into the resolving and refined mid-range, or the outstanding definition and separation of both the mids and the treble. The incredible treble extension and clarity, as well as the energetic and sparkling higher frequencies without any harshness or brightness, speak for themselves. The sound is smooth and rich, yet lively and spirited, revealing but not overwhelming, polite and refined, as long as you ensure to provide the Silver Fox with high-quality audio content.
The Silver Fox enhances the realism of the presentation with its three-dimensional images, robust sound quality, and lively performers that seem to come alive right in front of you. The textures are rich, the bass is powerful, the mids are full-bodied, and the treble is well-balanced. Experience a grand and immersive sound that will make your headphones feel like speakers.
The Silver Fox, unlike other amplifiers, delivers exceptional sound quality across all volume levels, catering to both low level listeners and party enthusiasts. Whether you prefer to listen at a lower volume or crank it up, you can be confident that you will fully appreciate your favorite music.
And more
The 9i-996 truly excels in its timbre realism, with deeply organic and analog sound that flows like spring water. The amplifier effortlessly produces music with amazing ease, offering colorful and harmonious sound with incredibly rich harmonies and diverse overtones. The tonality is so realistic that the overall performance can only be compared with high-end tube amplifiers. The lifelike presentation creates a deep, emotional engagement that makes it impossible to stop listening. The sound is free of any artificiality, metallic sheen, glare, harsh or raw treble, dry bass, lean mids, lack of fluidity, or absence of lushness.
The soundstage of the 9i-906 is exceptional, offering a vast, roomy, and expansive feel without any artificial exaggeration. It is both broad and deep, showcasing remarkable layering and incredibly precise imaging. The presentation is grand and holographic, providing all the necessary time and spatial details. When listening to live recordings, it feels as if you are right there in the moment, thanks to the 9i-906’s effective communication of ambiance and atmosphere. For the ultimate music experience, combine it with a DAC that sounds equally natural and your top-quality headphones, and get ready for an immersive musical journey.
The Silver Fox is compatible with a variety of sources and headphones, provided they are capable, and it shows appreciation for all music genres. However, its true brilliance is revealed when paired with grand symphonic and choral compositions. These types of music truly showcase the device’s full potential, highlighting its diverse capabilities and complexity.
Further sound shaping
I will not delve into a detailed comparison of the four output modes and their varying sound characteristics, as the results are subjective and heavily dependent on the headphones and audio source. I observed subtle yet distinct differences with most of my headphones, particularly in the timbre and dynamic range. It is reasonable to assume that the BTL mode best represents the amplifier’s true potential and is the optimal choice for most headphones. However, I particularly enjoyed the additional harmonic variety of the Active G mode, and I believe you will have a great time experimenting to find your preferred output mode, especially when combined with the impedance selector.
Vs the Flux Labs Mentor and Violectric V550
Prior to encountering the Cen.Grand 9i-906, my top-rated solid state amplifiers were the Flux Lab Acoustics Mentor ($1299) and the Violectric V550 (€2599). These were the most high-end equipment I had experienced up to that point. I will keep this comparison brief, as if you have read this far, you are likely feeling fatigued. I will not factor in functionality and value, as those shopping for high-end gear are typically focused solely on achieving the highest possible sound quality.
In terms of sound quality alone, the Cen.Grand outperforms both other amplifiers. While the differences may not be drastic, as both amplifiers are already top-notch, they are significant enough to justify the additional cost. It’s important to remember that in the high-end realm, the law of diminishing returns comes into play, meaning you have to invest more to see slight improvements. The Cen.Grand 9i-906 combines all the strengths of the other two amplifiers (as highlighted in their respective reviews), eliminates their weaknesses, and then goes above and beyond to create the ultimate headphone amplifier in terms of sound quality.
Lean textures? Nonexistent. Absence of dynamic impact? Nonexistent. A little monitoring and sterile? Nonexistent. Soundstage not as holographic? Nonexistent. Overly polite? Nonexistent. Not quite organic and natural? Nonexistent. Somewhat dry and lacking in visceral impact? Nonexistent. I believe you understand the point, so I shall cease here.
If budget is not a concern and you are willing to overlook certain features, the Cen.Grand 9i-906 amplifier is the best choice for the best possible sound quality of your headphones without any drawbacks in terms of sonic performance. However, if you can’t afford it, both of the other amplifiers are excellent choices in their own right. In particular, the Flux Labs Mentor stands out as offering exceptional value in the market.
In the end
The Cen.Grand 9i-996 is easily the best sounding and most powerful, solid state headphone amplifier that I have heard up to date. The sound performance is really flawless and this amplifier embodies all the sonic virtues that high-end gear should have. I am not that naive to suggest that it is the best amplifier on the planet, after all I haven’t tested everything, but on the other hand I can’t see how it can be surpassed, especially if we leave tubes out of the equation.
The Cen.Grand 9i-996 is comparable to the rarity of the Silver Fox. This exceptional amplifier delivers top-notch sound quality, enhancing the performance of all headphones and sources, regardless of their quality or price range. Its price is remarkably competitive considering its high audio performance level, warranting the term “value” to describe it, even when referring to high-end equipment. I am confident that if it were manufactured by a reputable Western audio brand, it would be priced at twice as much. Therefore, the 9i-906 stands out as the best value for money in the high-end headphone amplifier market.
Copyright – Petros Laskis 2024.
+ Class leading sonic performance
+ Class leading technicalities
+ Class leading transparency
+ Class leading timbre realism
+ Class leading musicality
+ Class leading soundstage
+ Class leading power output
+ Class leading dynamics
+ Extremely well made
+ Various options for headphone matching and sound shaping
+ Multiple inputs and outputs
+ High-end value
- Without remote control
- No preamplifier function
- Big size not suitable for desktop use
- No real gain settings
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