The warranty period on FiiO K11 R2R is for 1 year. To read more information click here.

1. Outlooking differences: FiiO K11 R2R comes with R2R logo while FiiO K11 does not have. The other appearances are same, 2. Internal circuitry differences: FiiO K11 uses CS43198 as the DAC chip, while the FiiO K11 R2R uses sign-magnitude R2R as the DAC chip. Some of the corresponding circuits are slightly different. 3. Parameters differences: The THD+N & Noise and noise floor of FiiO K11 and FiiO K11 R2R are nearly the same. 4. Software settings function differences: FiiO K11 uses the CS43198 as DAC chip so it comes with a filter setting function. The FiiO K11 R2R uses sign-magnitude R2R as the DAC chip, so it has no filter function and the filter setting option is removed. But the oversampling mode and smart idlefunction are added for FiiO K11 R2R.




[No sound, noise, unable to boot, indicator light off, etc.] You can try the following methods to help you solve the problem: 1. Restart FiiO K11 R2R; 2. Re-plug the power cord. How to restore factory firmware for FiiO K11 R2R? (FiiO K11 R2R comes with backup system. When you meet the system failure (for example fails to enter menu), you can try to restore the factory firmware via the backup system. 1.When FiiO K11 R2R is powered off, long press the knob to turn it on. Keep holding when 'FiiO' shows and stop holding when the screen turns off. The display will shows 'bACkUP' and you can enter the backup mode. 2.In the backup menu, click the knob to enter the selection menu, then scroll the knob to select between REVERT/UPDATE/RETURN options. When selecting 'REVERT', the system will restart and enter the backup system (i.e. factory firmware system). At this time, the system will overwrite the system with part of the code of the backup system, and then restart automatically. Then the basic backup system becomes a normal available system. (Nomater the normal system fails or not, after selecting 'REVERT', the original system will be overwrited with the backup system) When selecting 'UPDATE', the system will enter the MCU update mode, the display will show 'RETURN'. You could exit the mode after updating. When selecting 'RETURN', the system will have no operation and restart automatically. [Over-current protection] FiiO K11 R2R doesn't have overload, over-temperature protection mechanisms but only over-current protection mechanisms. After the protection is triggered, you must turn off the power to restore it. You can turn it off and then on through the knob, or directly unplug the power supply to restore it.

To connect the FiiO K11 R2R to an Android phone, player or Apple phone, you need to purchase an additional Type-C to Type-C, lightning to Type-C OTG cable (such as FiiO LT-TC1, LT-LT3) to connect: 1. After the FiiO K11 R2R is turned on, use the OTG cable to connect to the mobile phone; 2. FiiO K11 R2R input mode switch to USB; 3. FiiO K11 R2R output setting: switch to the corresponding output port according to the interface used, switch the headphone or speaker output on the front panel to PO, and switch the line output on the rear panel to LO to decode the audio signal of the mobile phone. 【Android phone】 After the mobile phone is connected to the FiiO K11 R2R through the purchased OTG cable, the song can be played on the mobile phone. After being decoded by the FiiO K11 R2R, it is output from the headphone port to enjoy high-quality music. [Note] If there is no sound after you connect, you need to pay attention to the following points: 1. Mobile phone playback software settings. If there is a USB output that needs to be turned on, some devices have to turn off the USB output to have sound; 2. Confirm that the mobile phone developer mode has enabled USB debugging; The mobile phone needs to open USB debugging, open "Developer options", and then open "USB debugging" or "OTG" function; 3. Confirm that the transfer cable supports OTG function, whether the direction of the cable is reversed; 4. Since the USB audio of various brands of mobile phones is not standardized at present, FiiO does not guarantee full compatibility. According to the above connection method, if it is not supported, it is recommended to try other mobile phones or connect to the computer DAC to rule out whether the hardware of some devices is bad (such The probability of the situation is small), if you can’t connect to the computer, you can contact our customer service for further confirmation. 【iPhone/iPad】 It is necessary to purchase a Lightning to Type C cable with OTG function (such as FiiO LT-LT3). Connect FiiO K11 R2R and iPhone/iPad/iPod, play songs and enjoy high-quality music. 【Note】 1. Only Apple devices with iOS10.0.2 and above systems are supported. Those with versions lower than this version can not be supported due to the Apple system itself; 2. When the iOS device is decoding, adjusting the volume of the iOS device is invalid and needs to be adjusted on the FiiO K11 R2R.

1. After powering on the FiiO K11 R2R, switch the input mode of FiiO K11 R2R to the corresponding input: OPT IN (optical fiber), COAX IN(coaxial), and connect to the corresponding optical fiber/coaxial input line; 2. FiiO K11 R2R output setting: switch to the corresponding output port according to the interface used, switch the headphone or speaker output on the front panel to PO, and switch the line output on the rear panel to LO to decode the audio signal of the mobile phone. 3. Scroll the volume knob and adjust the volume of the FiiO K11 R2R to a suitable level before playing music. And select the GAIN (gain) according to personal preference; 4. Play music on the front device to enjoy the music. Note:When there is no output from the K7, please try to play other music first.

The AC power input of the power adapter comes with FiiO K11 R2R supports AC power between 100V and 240V. The specification of the DC port for FiiO K11 R2R is 5.5x2.1mm. The DC output of the power adapter comes with FiiO K11 R2R is 12V/2A. You could use 12V3A power supply as well. It is recommended to use the power adapter that comes with the FiiO K11 R2R or FiiO linear power supply PL50.