---
product_id: 77903144
title: "Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable)"
brand: "fosi audio"
price: "172261₫"
currency: VND
in_stock: false
reviews_count: 13
url: https://www.desertcart.vn/products/77903144-fosi-audio-p1-tube-preamplifier-mini-hi-fi-stereo-preamp
store_origin: VN
region: Vietnam
---

# 12V Power Supply 2 Channels Compact Design Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable)

**Brand:** fosi audio
**Price:** 172261₫
**Availability:** ❌ Out of Stock

## Summary

> 🎶 Elevate Your Audio Game with Fosi!

## Quick Answers

- **What is this?** Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) by fosi audio
- **How much does it cost?** 172261₫ with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/77903144-fosi-audio-p1-tube-preamplifier-mini-hi-fi-stereo-preamp)

## Best For

- fosi audio enthusiasts

## Why This Product

- Trusted fosi audio brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact Powerhouse:** Small footprint, big impact—perfect for any setup.
- • **Unleash Your Sound:** Transform your audio experience with rich, dynamic tones.
- • **Built-in Protection:** Enjoy peace of mind with overheat and impact protection.
- • **Versatile Connectivity:** Easily connects to computers, phones, and more.
- • **Tube Replacement Flexibility:** Customize your sound with interchangeable tubes.

## Overview

The Fosi Audio P1 Tube Preamplifier is a compact, high-fidelity preamp designed to enhance your home theater audio experience. With RCA inputs and outputs, it connects seamlessly to various devices, delivering rich sound through replaceable 6K4 tubes. Built-in protection circuits ensure longevity, making it a reliable choice for audiophiles.

## Description

Product description 6K4 Tube Preamplifier Our Story At Fosi Audio, our mission is simple yet powerful: to create products that produce exceptional sound quality and inspire people to listen to music on a daily basis. With a diverse range of Hi-Fi audio products available, we take pride in designing, manufacturing, and selling premium audio gear that aids your journey towards the perfect music experience. Choose Fosi Audio for an unparalleled Hi-Fi music experience. Tube Preamp Product Parameters Power Adapter Output: 12V/1.5A Product Adapter Input Voltage Range: AC 110V - 240V SNR ≥ 98dB THD ≤ 0.1% Treble adjustment range: ±6dB Bass adjustment range: ±10dB Input Mode: RCA Frequency Response: 20HZ -20KHZ((±3dB) 2 Channel Power Amp: BT10A, BT20A, BT20A Pro, TB10A, TB10D, V1.0B, V1.0G, TDA7498E, ZK-1002, ZK-502T. 2.1 Channel Power Amp: BT30A, BT30D, BT30D Pro, BL20A, BL20C, ZK-TB21. DAC: DS1, DS2, Q4, K5 Pro. DAC Amplifier: DA2120A, DA2120C. Subwoofer Amp: TP-01, TP-02, M01-BT, M02, M03, M04. Phono Preamp: BOX X1, Box X2, BOX X3, BOX X4. Tube Preamp: P1. Tube Headphone Amplifier: T20, T20X, P2. Enhance Your Audio with Tube Preamp featuring Controllable Bass and Treble Experience a significant improvement in sound quality with this preamp! Enjoy a warm and smooth audio experience with exceptional clarity and depth. Elegantly Designed Preamp with Intuitive Features for Effortless Use Connect the Fosi Audio P1 with ease to your power amplifier or active speakers, without the need for any software installation or changes to settings. Superb Audio Quality with Dual 6K4 Vacuum Tubes Experience powerful, dynamic, and sweet tube sound with the Fosi Audio P1 preamp! Utilize any of the following vacuum tube models for optimal sound quality: 6J1, 6AK5, EF95, 5654, 403B, and more.

Review: Great for getting a feel for how tubes affect sound - This little preamp provides a great introduction into tube amplification, both the benefits and drawbacks of using tubes. First of all, as this is a preamp, it is very easy to set up direct A/B comparisons with commodity recording equipment (namely USB recording interfaces). Run a line out recording through the preamp, and again direct, match the output levels, and you now have a better insight into what these tubes are actually doing to the sound with A/B testing (preferably blind ABX testing). The good news - this preamp is pretty quiet and does a good job amplifying the signal coming in. I've had zero issues with noise including this in my playback chain. For a component containing tubes it is surprisingly quiet. The bad news (depending on your point of view) - the EQ knobs on this device affect the sound output far more than the tubes themselves. This is not a knock on the quality of the EQ, no, in fact, the EQ knobs are actually very useful given there is only a treble and a bass knob. In fact, the preamp is almost worth the price of the device given how well these work. The tubes themselves work as advertised. Sending a sine wave through the preamp, I definitely see way more second-order harmonic distortion through the preamp than through a direct output without the preamp. For instance, with a 440 kHz sine wave, I see the expected bump of 880 kHz at -30dB from the main signal. And there is noticeable compression running high-volume sounds through the preamp, particularly when running into the preamp at higher outputs. In short the expected effects of the tube (even order harmonics and compression) are measurable with sufficiently juiced inputs using relatively inexpensive measuring equipment. The real question is whether these effects are noticeable by your ears. For me at least the answer is yes, but the effect is pretty subtle, nowhere near what I was anticipating. For better or worse the stock tubes actually perform very well and have a good amount of headroom available before you notice any obvious changes in the sound. You kind of have to go out of your way to hear obvious changes, though, whether that be with bass-heavy music (Sublime's 40oz to Freedom works great for this) or by deliberately overdriving the inputs. A fun quantification of how this preamp affects sounds is to do a null test. First capture a recording of music played through the preamp tube, and then do the same exact source without the preamp tube. Line up both recordings *exactly* to the sample and to the same level, then invert the phase of one of them. Play them together and you'll get an exact audio representation of the difference between both input modes. This is more difficult than it sounds but if you do it you will hear the obvious distortions being introduced by the tubes. The interesting part is that they are both almost inaudible (unless you are carefully listening for them), and that even though these distortions sound not so great by themselves, when mixed into the output they can actually improve the sound of the music. OK, enough navel-gazing for now. Is this worth purchasing if you want to understand what "magical" tubes do? Absolutely. Is the effect going to be obvious? Probably not, unless you swap in tubes that are either busted or have very low headroom. Oh, and if you want to get an easy check for whether the tubes are actually in the signal path, grab a pencil and (gently) tap on each tube. As long as you don't have a fake you should hear the taps through your output speaker/headphones. There shouldn't be any ringing from the taps - that would indicate the tubes have gone bad and are microphonic - but you should be able to hear something with the volume up high enough. And the sound volume should increase gradually after a cold start like any self-respecting tube would. Speaking of tubes, I wish the silly LEDs under the tubes were not included. Even though this is just a preamp there is enough voltage running through the tubes to emit a slight glow after the tubes have warmed up. The red LEDs that turn on when powered up are *sort* of useful to make sure the device is working, but ultimately silly as it looks super fake compared to a real tube glow.
Review: A "Must Have" for Any Serious Audiophile - I’ve been a Stereo Hi-Fi enthusiast since the mid-70s, and quality Hi-Fi equipment can be outrageously expensive. I was quite pleased to find this little device for under $50. I’ve already invested over $5000 in my sound system, but even so, the sound coming from my streaming audio source was less than satisfactory. It lacked the clean, crisp sound that you get from a vinyl record. My goal was to get the best sound from all my streaming music sources: Napster, Sirius XM, desertcart Music, and Music Choice on Xfinity. All of these music services are on my Dell computer using Windows 10. I am running a dedicated 50-foot cable to my stereo power amplifier. Without the Fosi preamp, my music was dull and lacked depth. The bass was muffled, and the vocals and instruments were a bit tinny. Before I connected the Fosi preamp to my sound system, I installed the GE 5654 tubes as recommended by other users. I was amazed at the transformation. I now get a clean crisp bass, rich vocals, and brilliant instruments. The music comes alive. The change was phenomenal. I highly recommend this little gadget for anyone who is a serious audiophile. One important note. If you don’t achieve great sound quality at first, you may need to make some volume adjustments on your software and devices. For example, my best sound came when I adjusted the volume settings on my computer; Windows volume setting at 90 and Napster volume setting at 5. It just takes a little time to find the right combination for your system. Also, I tinkered with the volume settings on the Fosi preamp and my stereo amplifier to achieve optimal sound. It took me about an hour to get it right, but you only need to do this once. Just play around with it. Even without making any volume adjustments, there still was significant improvement in the sound quality using the Fosi preamp. Pros: Price. Solid metal construction. Easy setup. Great sound. Cons: A little difficult to install the tubes.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07GXBF5JS |
| Best Sellers Rank | #440,284 in Electronics ( See Top 100 in Electronics ) #213 in Audio Component Preamplifiers |
| Brand | Fosi Audio |
| Brand Name | Fosi Audio |
| Customer Reviews | 4.5 out of 5 stars 722 Reviews |
| Item Dimensions | 5 x 5 x 1 inches |
| Item Weight | 0.5 Kilograms |
| Item dimensions L x W x H | 5 x 5 x 1 inches |
| Manufacturer | Fosi Audio |
| Material Type | aluminum alloy |
| Maximum Supply Voltage | 12 Volts |
| Minimum Supply Voltage | 12 Volts (DC) |
| Model | P1 |
| Number of Channels | 2 |
| Package Type Name | box |
| Part Number | P1 |
| Unit Count | 1.0 Count |
| Voltage | 12 Volts |

## Product Details

- **Item dimensions L x W x H:** 5 x 5 x 1 inches
- **Manufacturer:** Fosi Audio
- **Maximum Supply Voltage:** 12 Volts
- **Minimum Supply Voltage:** 12 Volts (DC)
- **Voltage:** 12 Volts

## Images

![Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) - Image 1](https://m.media-amazon.com/images/I/51bZYGDSJBL.jpg)
![Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) - Image 2](https://m.media-amazon.com/images/I/61neXr3VrfL.jpg)
![Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) - Image 3](https://m.media-amazon.com/images/I/717o3cifsoL.jpg)
![Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) - Image 4](https://m.media-amazon.com/images/I/619lCJ+ybJL.jpg)
![Fosi Audio P1 Tube Preamplifier Mini Hi-Fi Stereo Preamp 6K4 Valve Vacuum Pre-amp with Treble Bass Tone Control for Home Theater HiFi System(not for Turntable) - Image 5](https://m.media-amazon.com/images/I/61OSj1Kkq6L.jpg)

## Questions & Answers

**Q: What kinda if tubes can i replace the stock ones with once they burn out?**
A: Hello, you can buy these tubes.
https://www.amazon.com/dp/B087LXW6RL

**Q: Can the fosi t2 headphone amp work with the fosi Q5 dac**
A: Assuming you mean the p2 headphone amp, yes, it will. You'll need an RCA cable to connect the two.

**Q: Was everyone satisfied with the quality of the vacuum tubes provided? If not, what might be a worthwhile upgrade?**
A: I've sampled Brimar 5749's and GE 5654's and the ones that came with -- the differences are subtle (the tubes on this are only for the pre-amp stage) -- no complaints for the $50 price tag -- it's as good as any headphone amp I've tried under $150  and mine has been working perfect for over a year

**Q: With this fossi amp for headphones , would it be wise to get your dac converter ? i’m using a iphone as the sorce of music**
A: Yes. That’s my setup. Works great

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great for getting a feel for how tubes affect sound
*by A***E on July 30, 2022*

This little preamp provides a great introduction into tube amplification, both the benefits and drawbacks of using tubes. First of all, as this is a preamp, it is very easy to set up direct A/B comparisons with commodity recording equipment (namely USB recording interfaces). Run a line out recording through the preamp, and again direct, match the output levels, and you now have a better insight into what these tubes are actually doing to the sound with A/B testing (preferably blind ABX testing). The good news - this preamp is pretty quiet and does a good job amplifying the signal coming in. I've had zero issues with noise including this in my playback chain. For a component containing tubes it is surprisingly quiet. The bad news (depending on your point of view) - the EQ knobs on this device affect the sound output far more than the tubes themselves. This is not a knock on the quality of the EQ, no, in fact, the EQ knobs are actually very useful given there is only a treble and a bass knob. In fact, the preamp is almost worth the price of the device given how well these work. The tubes themselves work as advertised. Sending a sine wave through the preamp, I definitely see way more second-order harmonic distortion through the preamp than through a direct output without the preamp. For instance, with a 440 kHz sine wave, I see the expected bump of 880 kHz at -30dB from the main signal. And there is noticeable compression running high-volume sounds through the preamp, particularly when running into the preamp at higher outputs. In short the expected effects of the tube (even order harmonics and compression) are measurable with sufficiently juiced inputs using relatively inexpensive measuring equipment. The real question is whether these effects are noticeable by your ears. For me at least the answer is yes, but the effect is pretty subtle, nowhere near what I was anticipating. For better or worse the stock tubes actually perform very well and have a good amount of headroom available before you notice any obvious changes in the sound. You kind of have to go out of your way to hear obvious changes, though, whether that be with bass-heavy music (Sublime's 40oz to Freedom works great for this) or by deliberately overdriving the inputs. A fun quantification of how this preamp affects sounds is to do a null test. First capture a recording of music played through the preamp tube, and then do the same exact source without the preamp tube. Line up both recordings *exactly* to the sample and to the same level, then invert the phase of one of them. Play them together and you'll get an exact audio representation of the difference between both input modes. This is more difficult than it sounds but if you do it you will hear the obvious distortions being introduced by the tubes. The interesting part is that they are both almost inaudible (unless you are carefully listening for them), and that even though these distortions sound not so great by themselves, when mixed into the output they can actually improve the sound of the music. OK, enough navel-gazing for now. Is this worth purchasing if you want to understand what "magical" tubes do? Absolutely. Is the effect going to be obvious? Probably not, unless you swap in tubes that are either busted or have very low headroom. Oh, and if you want to get an easy check for whether the tubes are actually in the signal path, grab a pencil and (gently) tap on each tube. As long as you don't have a fake you should hear the taps through your output speaker/headphones. There shouldn't be any ringing from the taps - that would indicate the tubes have gone bad and are microphonic - but you should be able to hear something with the volume up high enough. And the sound volume should increase gradually after a cold start like any self-respecting tube would. Speaking of tubes, I wish the silly LEDs under the tubes were not included. Even though this is just a preamp there is enough voltage running through the tubes to emit a slight glow after the tubes have warmed up. The red LEDs that turn on when powered up are *sort* of useful to make sure the device is working, but ultimately silly as it looks super fake compared to a real tube glow.

### ⭐⭐⭐⭐⭐ A "Must Have" for Any Serious Audiophile
*by S***L on December 25, 2021*

I’ve been a Stereo Hi-Fi enthusiast since the mid-70s, and quality Hi-Fi equipment can be outrageously expensive. I was quite pleased to find this little device for under $50. I’ve already invested over $5000 in my sound system, but even so, the sound coming from my streaming audio source was less than satisfactory. It lacked the clean, crisp sound that you get from a vinyl record. My goal was to get the best sound from all my streaming music sources: Napster, Sirius XM, Amazon Music, and Music Choice on Xfinity. All of these music services are on my Dell computer using Windows 10. I am running a dedicated 50-foot cable to my stereo power amplifier. Without the Fosi preamp, my music was dull and lacked depth. The bass was muffled, and the vocals and instruments were a bit tinny. Before I connected the Fosi preamp to my sound system, I installed the GE 5654 tubes as recommended by other users. I was amazed at the transformation. I now get a clean crisp bass, rich vocals, and brilliant instruments. The music comes alive. The change was phenomenal. I highly recommend this little gadget for anyone who is a serious audiophile. One important note. If you don’t achieve great sound quality at first, you may need to make some volume adjustments on your software and devices. For example, my best sound came when I adjusted the volume settings on my computer; Windows volume setting at 90 and Napster volume setting at 5. It just takes a little time to find the right combination for your system. Also, I tinkered with the volume settings on the Fosi preamp and my stereo amplifier to achieve optimal sound. It took me about an hour to get it right, but you only need to do this once. Just play around with it. Even without making any volume adjustments, there still was significant improvement in the sound quality using the Fosi preamp. Pros: Price. Solid metal construction. Easy setup. Great sound. Cons: A little difficult to install the tubes.

### ⭐⭐⭐⭐ Fosi tube buffer
*by G***D on August 17, 2019*

Only have about 30-40 hours of listening on the unit. Installed nos GE 5654 tubes at turn on. My initial reaction is that this unit effects sound quality far more than the buffer it replaced, which failed. Took the edge off of high frequency issues with my analytical system that tends to be on the bright side along with my room which adds to the problem. I have some RCA nos 6AK5's I may swap in later if I detect any artifacts that I don't care for. The unit imparts a fleshier low mid-range/high bass which compliments my speakers nicely in addition to taming treble as noted. This would be a 5 star if it had a tone control defeat switch. Very happy with the unit. I do have some suggestions for FOSI though. 1. Supply the buffer with a tone control defeat switch. 2. Supply a SE edition with higher quality passive parts along with 1. noted above and keep the upgrade cost $20 to $30 more. You would knock the ball out of the park with this edition. This combination along with a good solid state pre-amp (if you need one) and solid state amp would give you some of the "tube magic" that many crave. Another interesting item that was not expected,is that Pandora jazz stations seem to place me a couple of rows closer to the performers and with a little bit of "air". Very unexpected but nice. One of the reasons for advocating for a tone control defeat switch is that my vinyl playback does not need tone shaping,however CD and streaming Pandora do need minor treble adjustments,down for cd's and a tad up for Pandora. Update 9-10-19 Now have 100 hours. Installed Voshkod tubes in place of GE 5654. About 40 hours on them. They are more dynamic than GE's but with a cooler presentatation. I really like them for jazz,however, like the 5654's for classical. Also have some RCA 6AK5's I may try in the future. The Fosi is a excellent piece of equipment.

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*Product available on Desertcart Vietnam*
*Store origin: VN*
*Last updated: 2026-06-07*