FOSI AUDIO BOX X3 Tube MM Phono preamplifier User Manual
- June 3, 2024
- Fosi Audio
Table of Contents
Fosi Audio BOX X3 Tube MM Phono Preamp
User Manual
Product Specifications
- Fosi Audio BOX X3 is a mini stereo Bluetooth 5.0 Hi-Fi tube phono preamplifier for MM turntable that features Volume control and Bass/Treble control with DC 12V power supply.
- The BOX X3 supports MM turntable input, 3.5mm AUX input or Bluetooth 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.
- The BOX X3 equipping with vacuum tubes stands up to the test and will provide you with serious sound performance.
Input Interface| MM turntable input,
3.5MM AUX input,
Bluetooth input, 12V DC input
---|---
Output Interface| RCA output
Output| Active(powered) speakers, Amplifier
Product Adapter Input Voltage Range| AC 100V – 240V
DC Input Voltage| 12V
Output Voltage Level| 1kHz and 650mV
SNR| 70dB
THD| ≤0.1%
Frequency Response| Standard RIAA
Product Weight| 0.34kg
Product Dimensions| 3.97×4.72×1.37 inch (10.09123.5 cm)
Product Overview & Control Functions
Front Panel
-
Input Indicator Light
-
3.5mm AUX Input
-
Treble Control
-
Bass Control
-
Multi-function Knob: Volume Control/Power Switch
Back Panel
-
DC Input
-
Bluetooth Antenna Interface
-
RCA Output
-
MM Turntable Input
-
Grounding Post
-
Bluetooth Antenna
Package Contents
Fosi Audio BOX X3 1
Bluetooth Antenna 1
Vacuum Tube 2
DC 12V Power Adapter 1
User Manual *1
Quick Setup
Step 1: Install the vacuum tubes to the BOX X3.
Step 2: Install the Bluetooth antenna to the BOX X3.
Step 3: • Use RCA cable to connect the RCA line output of BOX X3 to your
active(powered) speakers.
- Or use RCA cable to connect the RCA line output of BOX X3 to your amplifier, then use speaker’s wire to connect the amplifier with your passive speakers.
Step 4: Connect the power adapter to BOX X3 and the socket Turn the
Multi-function Knob(Volume Control/Power Switch) clockwise to power on the BOX
X3.The the input mode indicator light (also the power indicator light) of BOX
X3 stays red after power is on.
Note 1: The power adapter does not have a power indicator light, so
connecting to the socket means power is on.
Note 2: Before connecting the power supply, please make sure that the BOX
X3 is in “OFF” position when connecting to the power adapter. Otherwise there
is a “POP” click sound from your speakers.
Note 3: Before connecting the power supply, please turn down the volume
control, the bass and treble control to 0 (always to the left) to avoid your
hearing from damage.
Step 5: Connect the audio source (MM turntable input, 3.5MM AUX input,
Bluetooth input ) to the BOX X3.
(1): MM turntable input: Use RCA Cable to connect your MM turntable to
the RCA inputs of BOX X3, then connect the ground wire of your MM turntable to
the grounding post of BOX X3.
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 mobile phones, MP3, etc.
(2): 3.5mm Input: Use a 3.5mm Audio cable to connect the BOX X3 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.
(3): Bluetooth Input: Turn on the Bluetooth on your device, then select
“BOX X3” for pairing, the input mode indicator light will stays blue after a
successful connection.
Note 1: Once Bluetooth is connected, the MM turntable input and 3.5MM
AUX input will be interrupted. If you want to use the RCA input again, just
disconnect the Bluetooth.
Input priority: Bluetooth Input > 3.5MM AUX input > MM turntable input.
Install the Bluetooth antenna to the BOX X3.
Note 2: Input Indicator Light : After BOX X3 is powered on, the input
indicator light on the front panel stays red either 3.5MM AUX input or MM
turntable input is successfully connected, and the input indicator light on
the front panel of BOX X3 stays blue when Bluetooth input is successfully
connected. inputs of BOX X3,
Note : Please keep the BOX X3 away from other electric device. The BOX X3
can’t use with a radio simultaneously.
When the connection is completed, Please turn on the BOX X3 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 X3, 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 X3 on?****
– Please know that when no inputs connected to BOX X3, 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 X3, then turn it on to check if
the noise still or not.
– If the noise disappear, the noise may from the 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 X3 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 volume down the “Treble” volume on the BOX X3 to check if the noise
volume follows or not.
– 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 X3 not the phono input. Also make sure
the grounding wire is connnected well with the BOX X3, 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 X3 to try again.
Note:
– If the noise still, please contact us via email at
support@fosiaudio.com.
– BOX X3 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 X3, amplifier or powered speakers all
are turned on and in working mode.
– 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 X3, if
the 3.5mm AUX input plug in, the MM input mode will be interrupted, and if the
Bluetooth paired, the 3.5mm AUX input and the MM input will be interrupted, at
this time if you want to use the line input, you need to disconnect the
Bluetooth connection first. (if the LED light stay on RED, means the BOX X3 is
in line in mode, if it stay on BLUE, means the BOX X3 is in Bluetooth mode)
– If the indicator light on the BOX X3 does not stay on, try another power
supply(Any DC12V power adapter can work with BOX X3, you can use the power
adapter of WIFI router or camera) that is suitable for the BOX X3. If the
indicator light on the BOX X3 is on after replacing the appropriate power
adapter, it means that the power adapter is probably broken, please contact us
to replace the power adapter; if the indicator light on the BOX X3 is still
not on after replacing the appropriate power adapter, it means that the BOX X3
is probably broken, please contact us to replace the BOX X3.
– Note: Make sure that all the cables are completely pushed into the
device.
3. My Bluetooth device cannot pair with BOX X3?****
– Make sure that BOX X3 is powered on.
– Make sure that BOX X3 is not paired with other devices.
– Make sure that the distance between your device and BOX X3 is not too long,
close your device to BOX X3 to have a try.
– Make sure there are no obstacles between your device and BOX X3, obstacles
will affect the Bluetooth operation distance.
– Please try to change another Bluetooth audio source to test.
– Please reconnect the power supply to the BOX X3, and move the BOX X3 to your
another room to have a try.
– Restart the BOX X3 and then try to connect again, try to use another brand
of mobile phone.
4. Why Bluetooth is intermittent?****
– Use another Bluetooth device to have a try.
– Ensure that there is no interference from other electronic equipment between
the BOX X3 and the audio source.
– Put your device close to the BOX X3.
– Replug the power adapter.
5. How to distinguish Power Switch and Volume Control?****
– Power switch means turn the power switch knob clockwise for one time to
power on the BOX X3.
– Adjusting the volume means turning the volume control knob clockwise to
adjust the volume.
6. How do you switch between inputs?****
– The BOX X3 supports three inputs: MM turntable input, 3.5mm AUX Input and Bluetooth Input. The priority of switching between the three inputs: Bluetooth input >3.5MM AUX Input >MM Turntable input.
7. Can I connect a headset and the active speakers to the BOX X3 3.5mm AUX input simultaneously?****
– No, the BOX X3 is designed with a 3.5 MM AUX input, not the 3.5MM AUX
headphone output. But you can connect to the powered/active speakers from the
RCA output connectors.
– Note: BOX X3 is a preamplifier, if you want to connect it to passive
speakers, you need a power amplifier.
8. 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 X3.
9. How to attach ground wire?****
– There is a post to attach the ground wire.
10. Is the gain enough to support MC cartridge?****
– No. It is for MM cartridge.
11. My turntable has a selectable built-in phono preamp or switch to the line. Can I still use this instead of my built-in pre-amp?****
– Yes, deselect the preamp on your turntable.
12. Can I hook the BOX X3 to the power amplifier for my system?****
– Yes. You can connect the BOX X3 to the power amplifier through the RCA output.
13. Can this work with my turntable and headphones?****
– No, it’s not design for headphones, and the 3.5mm AUX connector on the front panel of the amplifier is input, not output.
14. 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.
15. What equalization is incorporated in this preamp?****
– RIAA equalization.
16. Can you hook a subwoofer to this unit?****
– Yes, if your subwoofer is powered, you can connect the BOX 3 directly to the subwoofer, but you need add a sub amplifier between the BOX X3 and the subwoofer if your subwoofer is passive subwoofer.
17.Which vacuum tube can be replaced to the BOX X3?****
– If necessary, tubes below are substituttions: 6K4/6J1/6J4/GE5654/6AK5/66*In vacuum tubes, etc. You can replace the vacuum tubes to DIY your stereo system.
18. Sound quality is not good?****
– Make sure all the cables are fully connected.
– Adjust the treble and bass of the BOX X3 to achieve the right tone.
– Please try to change the sound source and cables to test.
19. Can it be left on all the time?****
– The BOX X3 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 X3.
20. Why the BOX X3 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
Warranty Information
- All Fosi Audio products have an 18-month limited warranty on parts and labor from the date of purchase. Please contact us if you have any problems.
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
fosiaudio@hotmail.com
https://h5.shengcai.net/wwei/url?url=H666G_V7w6G
Fosi Audio Product’s User Manual