$42 for a tube preamp sounds insane; it seems way too good to be true, I mean $42? Really? I didn’t expect much from the Fosi Audio P1 Tube Preamp, but it was on sale on Amazon and had a coupon as well.

Fosi Audio P1 Tube Preamp

I couldn’t pass up the deal for something like this. In case you didn’t know, Fosi Audio is an audio equipment brand that aims to provide exceptional sound performance at an affordable price. With a focus on innovation and excellence, Fosi Audio is committed to delivering state-of-the-art audio solutions that meet the diverse needs of music enthusiasts and professionals alike. From amplifiers to DACs, preamplifiers, and more. They primarily sell on Amazon, AliExpress, and their own website. Let’s jump right into the review!

Fosi Audio P1 Tube Preamp Specifications

≥ 98dB


≤ 0.1%

Treble adjustment range:


Bass adjustment range:


Input and output:

One pair RCA each.

Frequency Response:

20Hz -20kHz (±3dB)

Listening System Specs


ASUS Prime B660-PLUS D4 Motherboard (built-in)




Acrylic A50+


Jamo S803 (yes, I got them to fit on my desk!)

Test Music


Lindsey Stirling – Crystallize
Nerv – Demons


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Fosi Audio P1 Tube Preamp Detail

The Fosi Audio P1 is an ultra-compact vacuum tube pre-amplifier that delivers exceptional sound quality in a small package. With its sleek and minimalist design, the P1 is a great choice for music enthusiasts who value both performance and aesthetics. The amplifier features two 6K4 tubes, that provide a warm and smooth sound that enhances the listening experience. The P1 also comes equipped with a quality power supply, ensuring stable and consistent performance. Overall, the Fosi Audio P1 is a versatile and reliable pre-amplifier that is perfect for both casual listening and professional use.

So, the real question is how does it sound? Honestly not bad, not one bit. The tubes provide some warmth to the sound I felt was lacking with the A50+ amplifier alone. While not a fan of tubes myself, the P1 is a very affordable and easy gateway into the world of tubes. The front EQ is more useful than it looks, allowing you to make quick treble and bass adjustments on the fly; it’s simple and powerful. I kept them at 12 o’clock for most of my listening, but with bass-heavy tracks, you can slightly turn it down as needed, it worked and sounded far better than expected. No distortion or other oddities could be heard, it sounded very clean. I can’t really pick out any bad-sounding spots in the highs or lows at all, it just sounded warm.

Fosi Audio P1 Tube Preamp Side View

While the P1 did a great job adding warmth, it also added in a light buzz, not easy to hear but putting your ear up to the speakers with no volume it can be heard. My guess is that a better power supply would solve that issue, but for the asking price it’s hard to complain. This unit is also quite lightweight but does run hot, as does anything with tubes. It still has a solid metal enclosure, and the knobs and power switch all feel great. I thought the overall build of this little unit would be way worse considering the rock-bottom price, but I am struggling to find anything else I don’t like about it. It’s not the best-sounding tube preamp I’ve heard by a long shot, but the price and value of this thing are insane. My only question that remains is how long it will last.


Fosi Audio P1 Tube Preamp Top View

Not bad at all, for $42 I expected less. This little tube preamp sounds as good as it looks in such a small value-packed unit. If you’re looking to do a value separates system for your desktop, this is a solid choice. If you can find a better power supply, that would be my first upgrade for this. As long as it keeps working, I see no reason why this wouldn’t make an amazing budget choice.