Fosi Audio in recent years has managed to stand out among the countless Chinese companies producing low-cost mini Hi-Fi equipment, becoming one of the best-selling brands in the sector on Amazon. As we have told you on other occasions, in recent years the Chinese company has been moving toward higher segments of the market, developing excellent class D amplifiers, DACs, headphone amplifiers and planar magnetic headphones, all characterized by cutting-edge technical parameters and well received by both critics and the public. Prices, moreover, remain very competitive.
After testing in recent months the V3 mono power amplifiers, the ZD3 DAC and the i5 planar magnetic headphones, we have now had the opportunity to test the new Fosi Audio preamplifier, the ZP3.
For a long time, hi-fi enthusiasts have seriously considered the idea of purchasing a preamplifier + power amplifier pair instead of an integrated amplifier, especially when assembling a high-level system. In this case, the management and selection of inputs from various sources and the volume level are handled by the preamplifier, while the power amplifier has the specific task of amplifying the output signal to drive the speakers.
The advantages of this solution lie in reduced mutual interference and greater flexibility of use. For example, you can replace one of the two components in the future or purchase two with different characteristics to achieve a more satisfying overall sound. Among the disadvantages, we note the larger footprint of the equipment, the need for additional cables between preamp and power amp which can affect sound quality, and not least the higher costs compared to an integrated amplifier with comparable features.
With the advent of mini class D amplifiers, however, even those who want to assemble a small, more affordable system based on an inexpensive amplifier of this type may find it useful to use a preamplifier. This is because mini class D amplifiers, while capable of delivering excellent sound quality, lack flexibility and connectivity options: in the vast majority of cases they feature only a single RCA line input and force users who want to connect multiple sources to constantly unplug and replug cables. Moreover, mini class D power amplifiers are becoming increasingly common, such as the V3 mono from Fosi Audio, which require a preamplifier to drive passive speakers.
The ZP3, Fosi Audio’s new preamplifier, is particularly suited to being used within a modern compact audio system, perhaps based on other Fosi Audio V or Z series equipment. The ZP3 is currently sold at a price slightly below €200 and can be conveniently purchased via Amazon.
Here are the technical specifications of the ZP3:
- Inputs: 2 RCA, 1 balanced XLR
- Outputs: 1 RCA, 1 balanced XLR, 1 SUB RCA (20–200Hz)
- Operational amplifier: dual NE5532, replaceable
- Volume control: NJR NJU72315 electronic
- Tone controls: treble, bass, balance, three-level high-pass filter (20Hz-20kHz, 80Hz-20kHz, 120Hz-20kHz)
Balanced XLR output specifications:
- SNR ≥ 112dB
- Dynamic range ≥ 112dB
- THD+N ≤ 0.0007%
- Noise floor ≤ 6uV
RCA output specifications:
- SNR ≥ 115dB
- Dynamic range ≥ 115dB
- THD+N ≤ 0.0008%
- Noise floor ≤ 4uV
Accessories include the remote control, power cable, a 3.5mm jack cable, and the user manual.
Two features in particular distinguish the ZP3 from most of the competition: the presence of balanced inputs and outputs and an adjustable high-pass filter for use with a subwoofer.
Now let’s move on to our test of the Fosi Audio ZP3
The ZP3 comes in a cardboard box that isn’t luxurious but is well packaged. Included in the package are the power cable, a basic manual, the remote control (without batteries), and a cable with two minijack plugs functioning as a “trigger” (allowing you to turn other connected Fosi Audio devices on or off simultaneously).
The front panel, very solid, is designed to match the look of other Fosi Audio “Z” series equipment. On the left side are grouped the power/input selection button and the tone and balance controls. On the right side is the large orange volume knob, clearly chosen to match other Fosi Audio components. On the rear panel we find two RCA inputs and one XLR input, one RCA output, one balanced XLR output, one mono RCA output for subwoofer, 12V trigger input/output, and the power socket.
Two very important controls—the tone control bypass and the high-pass filter for subwoofer use—are located under the chassis, making it impossible to change their position while the unit is operating. This is a real shame: being able to enable/disable tone controls on the fly and adjust the low-frequency cutoff can be very useful. The high-pass filter can be set to three values: 20Hz-20kHz (effectively off), 80Hz-20kHz, 120Hz-20kHz. Its purpose is to prevent the lowest frequencies from reaching the speakers when using a subwoofer, ensuring these frequencies are reproduced only by the subwoofer itself.
Now let’s move on to our listening impressions: we tested the ZP3 over an extended period alongside Hifiman DACs EF400 and EF500, Fosi Audio ZH3 and ZD3, and the V3 mono power amplifiers from Fosi Audio, as well as Sure Electronics boards based on TPA3116 and Tripath TK2050 chips used as power amps, and speakers such as Indiana Line Nota 260X and Lonpoo LP42.
With tone controls disabled, the ZP3 sounds very transparent and detailed, with a slightly bright presentation characterized by tight, clean, controlled bass. For this reason, we see it pairing well with sources that have a warmer or neutral sound, but not overly analytical, to avoid listening fatigue over time.
The soundstage is one of the ZP3’s strengths: very wide and deep, with well-separated and believable instruments. The tone controls (treble ±6dB, bass ±12dB) can alter the ZP3’s sonic signature and help tailor the sound to your preferences: even small adjustments are noticeable, adding a degree of fun. More advanced users can also experiment by replacing the stock op-amps with different ones to explore changes in sound performance. The included remote control, very simple, allows you to change inputs, adjust volume, and even control other Fosi Audio devices without getting up.
The least convincing feature of the ZP3 is the volume control, which is electronic and of the “infinite rotation” type. There’s no way to know the volume level until you start playing music, with the risk of damaging your ears or speakers if the volume was set too high before turning the unit off. Additionally, the “steps” of the volume knob are relatively few, and with powerful amplifiers or very sensitive speakers, you may find it difficult to set the ideal volume: too low at one step, too high at the next.
In conclusion, the Fosi Audio ZP3 is a preamplifier with distinctive features in its price range. Solidly built, equipped with balanced inputs and outputs, a high-pass filter to optimize systems with subwoofers, and a remote control, it delivers a particularly open, clean, and detailed sound. Few other products offer these features at this price point. While not without flaws—starting with the volume control—given its excellent value for money, the ZP3 is highly recommended for those looking for an affordable preamplifier with advanced features such as balanced XLR connections and a subwoofer output with high-pass filter. For those who don’t need these features and want to spend even less, the Fosi P4 is worth considering.
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