CEN.GRAND 9i-90SA Pro II “Lark” Headphone Amp/ DAC/ Pre-amp

The 9i-90SA Pro " Lark " consists of the following parts:

1. USB interface. XMOS second generation XU208 + FPGA digital processing module, isolation technology is used to isolate noise from the computer. Support for Native DSD512 and PCM384 input.

2. CT5302 + ESS 9038Pro DAC chip. The SPDIF receiver has three interfaces: coaxial, optical, and AES, support PCM 24bit/192KHz and DOP (DSD64) inputs.

3. Headphone amplifier. It has 6.35 unbalanced interface, 4-pin XLR balanced interface and 4.4 balanced interface. It has four output mode: Normal, BTL, Active Ground and Parallel.

4. Pre-Amp consisting of discrete components. It can be used as a pre-amp, the input interface is RCA and XLR, with infrared remote control.

5. Power supply and display system

An ESS 9038Pro DAC chip is used. There are 8 internal DAC in 9038Pro chip. Most of DAC which used 9038Pro chip only use one of them. The others are idle. The mode of multiple DAC channel parallel has many advantages, but it is not easy to get good sound and heating is serious. The 9i-90SA Pro works in 2 channel parallel mode.

There are 4 modes of connecting to headphone. Each mode has its own characteristics, and the difference is obvious. This function is very useful for the end user because he can choose the most suitable mode for his headphone. Under normal conditions high-impedance and high-quality headphones are suitable for Balanced (BTL) mode, in this mode the headphones can fully be driven by Amp. When your headphones are easier to be driven, you can choose parallel or Active G mode to drive them, as well as Normal mode. Next, I would like to introduce what is the "Virtual Ground (Active G)" mode.

Usually the positive terminal of the headphone cable should be connected to the positive output, and the negative terminal should be connected to the GND. If we make the input terminal of amplifier to GND, its output will get 0 level, which is the same level as GND. At this time if the negative terminal of the headphone is connected to the 0 level, it is equal to connected GND. But this is not the real GND, only simulated GND, that is to say "virtual GND" (Active Gnd). This kind of connection can get a more unique sound, the listening experience is warmer and softer, more suitable for listening to human voice or string. In short, the "virtual GND" (Active G) mode provides users with an effective tuning method that increases adaptability and entertainment.

The second generation of XMOS is the latest XMOS solution which is faster than last. Isolation technology enables blocking between the computer and 9i-90SA Pro. The ground wire is not connected so noise was almost completely isolating from the computer. This feature is very effective because there are a large number of switching power supplies inside the computer that generate a lot of noise which can interfere with the analogue circuit, audio performance will be degrade. Isolating these noises can significantly improve the purity of the sound.

The LPF is a balanced structure and a high-performance OP Amp LM49720 was used. The analogue output section is composed of a discrete device architecture which has been carefully tuned to correct the sound. The volume control chip is PGA2311 which controlled by MCU and the volume range is -70db~0db. Its common volume has been optimized, volume adjustment and listening habits are more coordinated and there are reliable protection measures.

The headphone amplifier uses a current feedback circuit. The technology of headphone amplifier is actually simple, and the key is adjustment. Drawing on extensive experience in Hi-Fi systems, we have achieved very good results in designing of the "Lark" headphone amplifier. It not only has strong driving ability but also sound balance, clear and delicate, strong sense of space. You can listen for a long time as well as forget the existence of headphones just like listening to the big HiFi system.

The display is OLED.

Use of 9i-90SA Pro

9i-90SA Pro is a DAC which with coaxial, optical, AES and other digital input interfaces. It can be used to upgrade CD player, or as an external DAC for digital players in your audio system. It has a volume adjustment function.

It is a fully balanced pre-amp with RCA/XLR input and output interface. Active speakers can be connected to it for building desktop hifi systems. You can also use it as a pre amp to connect to your power amplifier to build a large hifi system.

It is a pure headphone amplifier. It drives both high and low-impedance headphones with good musical expression.

It is an advanced USB DAC with the second generation of XMOS. The driver is a customized version and is a good choice for PC Hi-Fi players.

The most common use of the 9i-90SA Pro: Connect this unit to your computer via a USB cable, the music data is transferred to the unit. USB supports DSD512/PCM384. The computer player is very compatible and powerful so it can play music in any format.

The 9i-90SA Pro's headphone amplifier has good quality and can drive mainstream high-end headphones. Its two output circuits enable it to adapt to both high and low-impedance headphones. Four output modes make the 9i-90SA Pro has good adaptability to various headphones. Whether 600 ohm high-impedance headphone or 30-ohm it can be well adapted.

Performance Parameter

• Maximum audio support specifications: SPDIF input - PCM192

• USB input - DSD512 PCM384

• Dynamic range: 115dB

• Signal to noise ratio: 115dB (A weighting)

• Frequency response: ±0.4 dB (20-20KHz A weighting)

• THD+N: -102dB (fs=96KHz /10KHz A weighting)

• Pre-level gain: 4db (volume is 0db)

• Output power: 1.5W (33 ohms distortion 0.5%) 0.5W (600 ohms distortion 0.017%)

• Dimensions: 260mm * 85mm * 280mm (WHD)

• Power supply: AC 110V-120V or 220V-230V 50-60HZ (Fuse specification: 6.3A)

• Gross Weight: 4.35kg