Fosi Audio BOX X2 - Hifi Tube Phono Preamp for MM Turntable Manual

Product Specifications

Fosi Audio BOX X2 is a Hifi tube phono preamp for MM turntable that features the Multi-function Knob which contains Power Switch and Gain Adjustment Switch with DC 12V power supply. The BOX X2 supports MM turntable input, 3.5mm AUX input and RCA line output for powered speakers or amplifiers for your home audio system. Compact ultra-low noise phono turntable preamp that converts phono signals to line level signals, which will provide you with serious sound performance.

Product Overview & Control Functions

Package Contents

Fosi Audio BOX X2 *1
Vacuum Tube *2
DC 12V Power Adapter *1

Quick Setup

Step 1: Install the vacuum tubes to the BOX X2.

Note 1: Electronic tube is not divided into left and right, check the pins before installing the electronic tube there is no deformation, if there is a deformation of the situation you can use your hand to dial the right.

Note 2: Please note that electronic tubes are fragile and need to be handled gently.

Step 2(OUTPUT): Connect speakers to the BOX X2.

RCA output: Use RCA cable to connect the RCA line output of BOX X2 to your active (powered) speakers. Or use RCA cable to connect the RCA line output of BOX X2 to your amplifier, then use speaker's wire to connect the amplifier with your passive speakers.

Step 3(INPUT): Connect the audio source (MM turntable input, 3.5MM AUX input) to the BOX X2.

1. MM turntable input: Use RCA Cable to connect your MM turntable to the RCA inputs of BOX X2, then connect the ground wire of your MM turntable to the grounding post of BOX X2.

Note 1: If your MM turntable is no need to connect a ground wire, the ground wire can be omitted.

Note2: MM Turntable Input can only be connected to the turntable, and cannot be used as a normal preamplifier connected to other audio sources, such as CD player, TV, etc. (2): 3.5mm Input: Use a 3.5mm Audio cable to connect the BOX X2 and your device.

Note: Once 3.5mm AUX plug in, the MM input will automatically interrupted, so the input mode will turn to 3.5mm AUX input.

Input priority: 3.5MM AUX input > MM turntable input.

Step 4: Connect the power adapter to BOX X2 and the socket. Turn the Multi-function Knob ( Power Switch/Gain Adjustment Switch) clockwise for one time to power on the BOX X2.

Note1: The power adapter does not have a power indicator light, so connecting to the socket means power is on.

Note2: Before connecting the power supply, please make sure that the BOX X2 is in "OFF" position when connecting to the power adapter. Otherwise there is a "POP" click sound from your speakers. When the connection is completed, please turn on the BOX X2 first, then turn on the amplifier (or powered speakers), at last turn on your turntable or other audio source, then enjoy.

Note: If you turn on the amplifier (or powered speakers) first, then turn on the BOX X2, there is a "POP" click sound from your speakers, it is normal that all the phono preamp have the same issues, please don't worry about it, the "POP" click sound will not damage your amplifiers or speakers.

Troubleshooting/QA

1. Get noise/humming when turn the BOX X2 on?
   • Please know that when no inputs connected to BOX X2, the default input way is MM input mode, in this mode, the gain of the amplify is much large then other input modes, so it's normal that will have some humming sound when no sound pass through.
   • Please unplug all the inputs from the BOX X2, then turn it on to check if the noise still or not.
   • If the noise disappear, the noise may from the audio source or audio cable, please exchange the audio source and the audio cable to try again.
   • If the noise still, the noise may from BOX X2 or amplifier/ speakers:
   • Please exchange the audio cables and amplifier (powered speakers) to have a try and make sure that the noise is from which devices.
   • Please check whether the gain is too high, if the gain is too high, the bottom noise may be more obvious.
   • Please make sure all the cables completely pushed into the device, incompletely connection will cause this issue.
   • Please make sure that your turntable is MM output and also make sure that it is phono output, some turntables built-in phono preamplifier, so it should connect the 3.5mm AUX input on the BOX X2 not the phono input. Also make sure the grounding wire is connected well with the BOX X2, please reconnect it to have a try.
   • Please keep this device away from other electronic devices, like the FM radio or WIFI router.
   • Please make sure the tubes is completely pushed into the socket, incompletely connection will cause this issue.
   • Please reconnect the power adapter to the BOX X2 to try again.

Note:

• If the noise still, please contact us via email at support @fosiaudio.com.
• BOX X2 is a preamplifier, not a power amplifier, can not be connected with passive speakers directly.

2. All cables are connected, but there is no audio output?

• Please check if your audio source, BOX X2, amplifier or powered speakers all are turned on and in working mode.
• Please check whether the light of the vacuum tube is always on after power on, check whether there is a problem with the vacuum tube.
• Please check if the music in your audio source is paused.
• Please make sure that you are chose the correct input mode of the BOX X2, if the 3.5mm AUX input plug in, the MM input mode will be interrupted, at this time if you want to use the MM input, you need to disconnect the 3.5mm AUX input first.
• If the connection is right but the BOX X2 does not work, please try another power supply (Any DC12V power adapter can work with BOX X2, you can use the power adapter of WIFI router or camera) that is suitable for the BOX X2. If BOX X2 works after replacing the appropriate power adapter, it means that the power adapter is probably broken, please contact us to replace the power adapter; if BOX X2 still not works after replacing the appropriate power adapter, it means that the BOX X2 is probably broken, please contact us to replace the BOX X2.

Note: Make sure that all the cables are completely pushed into the device.

3. How to distinguish Power Switch and Gain Adjustment Switch?

• Power switch means turn the power switch knob(multi-function knob) clockwise for one time to power on the BOX X2. Adjusting the gain means turning the gain adjustment knob (multi-function knob) clockwise all the time to adjust the gain.

4. How do you switch between inputs?

• The BOX X2 supports two inputs: MM turntable input, 3.5mm AUX Input.
  The priority of switching between the two inputs: 3.5MM AUX Input > MM Turntable input.

5. My turntable doesn't have a ground wire connection. Does this need a ground wire hooked up for it to be able to work?

• No, it does not need a ground wire to operate. However, if your turntable has any ground loop, it will be piped and amplified through the BOX X2.

6. How to attach ground wire?

• here is a post to attach the ground wire.

7. How does grounding post work? My turntable has fork spade type Terminal?

• You can connect the fork spade type terminal to the grounding post.

8. Does this have analog to digital conversion?

• No. This product is a phono preamp/tube preamplifier.

9. Is the gain enough to support MC cartridge?

• No. It is for MM cartridge.

10. My turntable has an optional built-in phono preamp or switch to the line. Can I still use this instead of my built-in preamp?

• Yes, deselect the preamp on your turntable.

Note: Please confirm whether your turntable has a built-in phono preamp, if there is a phono preamp, and it cannot be deselected, then you can only connect 3.5 mm input, can not connect MM Turntable input.

11. Can I hook the BOX X2 to the power amplifier for my system?

• Yes. You can connect the BOX X2 to the power amplifier through the RCA output.

12. Can this work with my turntable and headphones

• No, this can not work with headphones, because it does not have headphones output.

13. Can I directly connect this phono preamp to the speakers?

• If your speakers are powered speakers, you can directly connect this preamp to the speakers. But you need to add an amplifier or receiver to the passive speakers.

14. What equalization is incorporated in this preamp?

• RIAA equalization.

15. Can you hook a subwoofer to this unit?

• Yes, if your subwoofer is powered, you can connect the BOX X2 directly to the subwoofer, but you need add a sub amplifier between the BOX X2 and the subwoofer if your subwoofer is passive subwoofer.

16. Which vacuum tube can be replaced to the BOX X2?

• If necessary, tubes below are substitutions: GE 5654 EF95, 6AK5, 6AK5W, 403A/403B, 6J1, 6J1P, 6J2, 6J3, 6J4, 6J5 vacuum tubes, etc. You can replace the vacuum tubes to DIY your stereo system.

17. Sound quality is not good?

• Make sure all the cables are fully connected.
• Adjust the gain of the BOX X2 to achieve the right tone.
• Please try to change the sound source and cables to test.

18. Can it be left on all the time?

• The BOX X2 is designed with a power switch. It can stay connected safely without power consumption all the time, you only need to turn off the power switch on the BOX X2.

19. Why the BOX X2 came with a broken vacuum tube?

• Due to long-distance transportation, the vacuum tube may be damaged during transportation. If you find that the vacuum tube is damaged or other problems, please contact Fosi Audio after-sales email immediately, and we will replace the vacuum tube for you.

Any problems please leave a message to the customer support email address: support@fosiaudio.com

Comparison Section

About Fosi Audio

• Fosi Audio designs and builds innovative audio products with all your music in mind. Great sound, simple but elegant designs, high-quality materials, and truly useful features are what Fosi Audio is about. We sincerely hope you get as much enjoyment from our products as we've had to create them!

Our website: www.fosiaudio.com
Amazon store: www.amazon.com/fosiaudio
Our Youtube channel: Fosi Audio
Our Facebook page: Fosi Audio

After-sale Service and Technical Support Email:
support@fosiaudio.com
customer@fosiaudioshop.com