Fosi Audio Box X4 MM Turntable Phono Preamplifier
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Fosi Audio Box X4 MM Turntable Phono Preamplifier
If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, within 24 hours on weekdays.
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Shipping Information
We offer free worldwide shipping, except for certain regions such as Ukraine and Russia, where our services are currently unavailable.
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Customer Support
WhatsApp: +8613716612254
support@fosiaudio.com
Mon-Fri: 3:00 AM - 3:00 PM PST -
FAQ’s
If you have any questions, please refer here: FAQs
Product details
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2021 NEW MODEL: The updated version for BOX X2. Next-generation phono preamp for unrivaled sound quality.
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JAN 5654W Tube MM Phono Preamplifier: The BOX X4 phono preamp supports 3.5MM AUX and MM turntable input, converting phono signals to Line Level signals with low-noise integrated circuits and high-quality components to remove low-frequency noise ensure clear sound quality. Designed with a grounding post to protect your turntable.
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Tube Headphone Amplifier & Preamplifier: The BOX X4 is designed with a 3.5MM AUX headphone and RCA output, highly useful beyond imagination.
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Applicable Vacuum Tube Model: 5654W/6K4/6J1/6J4/GE5654/6AK5/66*In vacuum tubes, etc. You can replace the vacuum tubes to DIY your stereo system. Different tubes with different sounds.
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What You Get: BOX X4 phono preamp, DC 12V power supply, user manual, our worry-free 24-month warranty, and friendly customer service.
Specifications
| Specifications | Details |
|---|---|
| Model | BOX X4 |
| Applicable headphone types | 16 Ω |
| Input Mode | MM turntable + 3.5mm AUX |
| Output Mode | RCA + 3.5mm headphone output |
| Output | Active(powered) speakers, Amplifier, Headphones |
| Frequency Response | Standard RIAA |
| THD | ≤ 0.1% |
| SNR | ≥ 70dB |
| Device Dimension | 4.72 x 3.97 x 1.37 inches |
| DC Input Range | 12V |
| Input Voltage Range | AC 110V - 240V |
| Output Voltage Level | 1kHz and 650mV |
| Power Supply | 12V 1.5A |
What‘s in the box？
| Item | Quantity |
|---|---|
| BOX X4 phono preamp | x 1 |
| Vacuum Tubes | x 2 |
| DC 12V power supply | x 1 |
| User's Manual | x 1 |
FAQs
Please read our FAQs page to find out more.
How to: Choose the right banana plug?
- Closed Screw Type. All Fosi amplifiers use standard-sized speaker terminals (4mm pins).
- Easy to wire up and solidly connect to amplifier and passive speaker.
- If they do not fit, use a little force to tighten the plugs.
- Fosi Audio Banana Plugs (Copper, Silver/Gold Plated): http://bit.ly/40Djq0U, https://bit.ly/3MkPL8t
- Please watch tutorial videos: https://youtu.be/6pYhoqDlvNw / https://youtu.be/RGvBgGAwS9k
How to Diagnose Power Supply Failure?
- The following situations may cause this issue
- Case 1: The LED on the power supply does not light up; Case 2: Amp/Preamp does not turn on; Case 3: When plugged into the Amp, both light on the amp & power supply start blinking; Case 4: Amp/Preamp make noise; Case 5: Sound shuts off by itself
- Possible solution
- Check if the power supply is illuminated when plugged into AC by itself.
Plug power supply into a different socket.
Test the adapter with a meter.
Try a different power supply (within a range of DC input).
Test the included power supply on other electrical equipment.
Please watch the tutorial video by clicking on the link provided. https://youtu.be/yCjygS03zTE
What are the differences in power outputs using the 32V and 48V power supplies?
- Using a more powerful power supply can help prevent distortion.
- Enables amplifier to drive larger, more powerful, or higher-impedance speakers.
What is a GaN?
- The GaN supply has a power output of 240W.
- Offers overload and over-temperature protection.
- The 48V 5A GaN power supply is also available on Amazon.
Customer Reviews
Have had this phono preamp for awhile. Produces a very good sound. I have a Denon DP-300F turntable. Sounds great when I am using my Grado 60s plugged in or I am sending it to my Yamaha RX-V800 receiver. Sound is better then using the pre-amp on the receiver. I listen to various Rock and Jazz genres.
A good preamp for turntable, but not good for Dac.
I was renovating my basement and had to disassemble my system and wanted something small to temporarily use in my living room so I ordered the BT10A and the Phono Box x4. I am powering a pair of GR Research XL-S Encores with the FOSi's hooked to my Pro-Ject turntable and was very surprised. Lots of bass and the treble was nice and sparkly. I can definitely recommend these two Fosi products.
This turntable (and “headphone”) preamp works very well for both of my vintage turntables (Sony PS-LX3 and Dual CS-616Q), producing clean and relatively warm sound. The bass and treble controls support fine tuning but I mostly leave them at the positions recommended by Fosi. Note that there is no center position detent. My only complaint is that it isn’t really a fully functional headphone preamp. It provides plenty of power for my Sennheiser cans but works directly only with the turntable as the audio input. If I want to listen with earphones for any other source I need to connect my Fosi ST20A PRO’s pre-out to the preamp line-in. That works okay but is needlessly kludgy.
After using this little valve pre-amp for a year now I am very impressed by its sound, build quality, and value. The device provides a wonderful warm analog valve sound that is distinctive when compared to the switchable built-in preamp of the Audio-Technica AT LT60x turntable. When plugged directly into the 3.5 in jack of a Sonos Five it creates the perfect budget analog audio setup with digital expansion capability for the future. The usefulness of physical volume and tone controls is a feature I use every day. Sometimes lo-tech is a good thing! Highly recommended.
