Fosi Audio P4 Amplifier
- Amplifier
- Fosi Audio
- 477 pounds
- 5.5 × 4 × 1.2 inches
- Better rated than 93%
A compact-footprint amplifier from Fosi Audio for tight desktop or shelf spaces, worth confirming wattage and input type directly before buying.
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How it ranks among the 57 amplifiers we track
4.7★ across 237 Amazon ratings, Bayesian-smoothed toward the category average.
237 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
Modest tracked demand last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 57 amplifiers we track - how the scorecard works · full amplifiers data report. Confidence: medium - useful but incomplete evidence.Last refreshed Aug 4, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
The Fosi Audio P4 is a compact amplifier measuring 5.5 by 4 by 1.2 inches, built for a desktop or small shelf setup rather than a full-size stereo cabinet, with wattage and input specs left undocumented in this listing.
Fosi Audio built its catalog around small amplifiers aimed at desktop and near-field listening, and the P4's footprint fits that pattern. Beyond the physical dimensions, the listing does not specify wattage, input type or speaker terminal style, so anyone comparing it to a specific receiver or speaker pair should confirm those details on the product page first.
- Desktop-scale amplifier
- 5.5 x 4 x 1.2 in dimensions
- Fosi Audio brand
- Compact footprint design
Who it's for
Suited to a desk or small shelf where a full-size receiver would not fit. Not the choice for anyone needing documented power output or multi-channel support, since neither is listed here.
Strengths and trade-offs
Drawn from this product's published specifications.
- Compact 5.5 x 4 x 1.2 inch footprint
- Fits desktop or small shelf setups
- No listed wattage or power output
- No input or terminal details given
Performance notes
At 5.5 by 4 by 1.2 inches, the P4 is sized to sit on a desk next to a monitor or on a shelf beside a pair of small speakers rather than in a full stereo cabinet. The listing does not include power output figures, so how it drives larger speakers is not something the spec sheet answers.
Specifications
| Brand | Fosi Audio |
|---|---|
| Model | P4 |
| Brand Tech | Fosi Audio |
| Weight | 477 pounds |
| Dimensions | 5.5 × 4 × 1.2 inches |
How it compares
This product against the closest alternatives we track in amplifiers.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| Fosi Audio P4 AmplifierThis product | 4.7 / 5 | 237 | 3.8 / 5 |
| Pyle PDA29BU.5 AmplifierPyle | 4.2 / 5 | 3,800 | 4.1 / 5 |
| WiiM AmplifierWiiM | 4.6 / 5 | 2,100 | 3.9 / 5 |
| Hama 00040506 AmplifierHama | 4.5 / 5 | 2,100 | 3.8 / 5 |
| Yamaha A-S301BL AmplifierYamaha | 4.6 / 5 | 1,200 | 3.8 / 5 |
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Questions about the Fosi Audio P4
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
What size is the Fosi Audio P4 amplifier?
It measures 5.5 by 4 by 1.2 inches.
Is the Fosi Audio P4 meant for desktop use?
Its compact dimensions suit a desktop or small shelf rather than a full-size stereo cabinet.