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Another Masterpiece Driven by Voice of Customers

The P4 is a mini preamp self-developed by Fosi Audio based on extensive feedback from users worldwide after the launch of the V3 stereo amp.

  • Input: RCA x3; Output: RCA, Pre-Out
  • SNR≥ 110dB; THD+N≤ 0.003%
  • Frequency Response: 20Hz-20kHz(±0.1dB)

Product details

Description
  • Mini Control Hub: The P4 supports up to 3 RCA inputs, allowing easy connection to CD players, streamers, DACs, cassette decks, and turntables with built-in phono preamp. Switch between sources with a click for seamless audio control.

  • Practical and User-Friendly: Equipped with volume control, bass and treble adjustment with bypass function, three-level gain control, and a remote. The preamplifier offers convenient audio setup and optimization, making every listening session effortless.

  • Motorized Potentiometer: Featuring a high-precision motorized analog pot, the P4 delivers smooth volume adjustment, reduced noise, and minimal distortion for a purer and more refined sound experience.

  • Compact and Solid: The P4 stereo preamp features a sleek, minimalist design that saves space and provides robust resistance to electromagnetic interference, ensuring reliable performance over time.

  • Exceptional Performance: With a low noise floor, high signal-to-noise ratio, and extremely low distortion, the P4 pre-amplifier delivers pristine audio, ensuring accurate sound reproduction and enhancing the listening experience for audiophiles
Specifications

Channel: 2.0
Input Mode: RCA*3
Output Mode: RCA, Pre-out
SNR: ≥ 110dB
Dynamic Range: ≥ 110dB
THD+N: ≤ 0.003%
Crosstalk: ≥ 105dB
Noise Floor: ≤ 9μV
Tone Adjustment Gain: ±12dB
Frequency Response: 20Hz-20kHz(±0.1dB)
Power Supply: DC 12V/1.5A

What‘s in the box?
  • Fosi Audio P4 Mini Preamplifier x 1
  • 12V/1.5A Power Supply x 1
  • User’s Manual x 1

Which Product is right for you?

Compare products to find the best one for your needs.

From $199.99

Fosi Audio ZP3 Preamplifer

Type
Preamp
Input
RCA x2, XLR
Output
RCA, XLR, Sub-Out
Bass & Treble Control
Yes
THD+N
≤ 0.0007%
SNR
≥ 115 dB
From $99.99

Fosi Audio P4 Mini Preamplifer

Type
Preamp
Input
RCA x3
Output
RCA, Pre-Out
Bass & Treble Control
Yes
THD+N
≤ 0.003%
SNR
≥110dB
From $79.99

Fosi Audio P3 Tube Preamplifier

Type
Preamp+Headphone Amp
Input
Bluetooth, RCA
Output
RCA, 3.5mm Headphone Jack, AUX
Bass & Treble Control
Yes
THD+N
≤0.02%
SNR
≥103dB

FAQs

Please read our FAQs page to find out more.

How do I integrate P4 into a audio system?

First, connect P4 to your audio sources via RCA cables, then connect P4 to an amplifier via RCA cables, and lastly, use speaker cables to connect the amplifier to the passive speakers.

What is the function of the Bypass switch?

This is the bypass function for turning the tone control on and off. Sliding it up bypasses the bass and treble adjustments while sliding it down enables the bass and treble controls. The bypass switch won’t function on the volume control.

What are the benefits of the high-precision motorized analog potentiometer in the P4?

It ensures smooth, precise volume control, and enhances usability while reducing noise and distortion. When adjusting the volume with the remote, the potentiometer‘s motor syncs with the physical knob, providing a seamless and intuitive experience.

What can the pre-out port used for?

Allows for easy connection to external powered subwoofers or additional amplification. It ensures seamless integration with your audio system, enabling enhanced bass response or driving additional speakers for a more immersive listening experience.

Customer Reviews

Based on 70 reviews
90%
(63)
9%
(6)
1%
(1)
0%
(0)
0%
(0)
M
Michal Cavojský

Fosi Audio P4 Mini Preamplifer

W
William Walker
Preamp review

I needed an a nice preamp and this little amp fills that need very well.
i have used the amp as a front end for several Phase Linear amps and Marantz units i have been working on. i found the quality to be exceptional.

J
John A
Excellent Analog Preamp

How I use the P4
TV and DVD player to Music Hall tube DAC 25.3 to Fosi P4.
Fosi P4 to Marantz 1060 to Monitor Audio speakers
Fosi P4 sub out to Yamaha powered speaker.
Great minimalist set up for the bedroom using the
Fosi P4. Base, treble work well as does the remote.
Impressed by the build quality and feel of the Fosi P4.
Have been looking for something analog and this works.

G
Gombocz A.
Great little device.

I love this little preamp from Fosi. I use it as a desktop device, next to an Xduoo tube headphone amp, an SMSL DAC, and AIYIMA A07 Max power amp. I like the design, and the simplicity of use, it is easy to replace the op-amp in it, but... Those buttons are hard to take off...

L
Leonard Downing
Perfect Specs - Perfection function

Simple, functional, ultra clean specs, quality build, just right connectivity, and pairs well with nicely matched Fosi Audio power amps. Mighty performance that stands equal next to larger, much more expensive pre amps. Large performance that does not dominate the wife approved decor of a room.