---
product_id: 147513418
title: "Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply"
brand: "fosi audio"
price: "632 Lei"
currency: RON
in_stock: null
reviews_count: 9
url: https://www.desertcart.ro/products/147513418-fosi-audio-m03-200-watt-tpa3255-subwoofer-amplifier-mini-mono
store_origin: RO
region: Romania
---

# 200W max power output TPA3255 chip for ultra-low distortion Switchable SUB/full-frequency modes Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply

**Brand:** fosi audio
**Price:** 632 Lei
**Availability:** ❌ Out of Stock

## Summary

> 🎧 Unleash deep bass and pristine sound—because your audio deserves the upgrade.

## Quick Answers

- **What is this?** Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply by fosi audio
- **How much does it cost?** 632 Lei with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.ro](https://www.desertcart.ro/products/147513418-fosi-audio-m03-200-watt-tpa3255-subwoofer-amplifier-mini-mono)

## 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 & Sleek:** Mini mono channel design fits seamlessly into any modern living space without sacrificing power or style.
- • **Plug & Play Ready:** Includes 32V/5A power supply and intuitive controls for quick setup and effortless bass tuning.
- • **Precision Audio Tech:** Equipped with Texas Instruments TPA3255 chip for crystal-clear sound with ultra-low distortion—hear every detail.
- • **Versatile Sound Modes:** Easily switch between full-frequency mono amp and dedicated subwoofer mode to tailor your audio experience.
- • **Powerhouse Performance:** Delivers up to 200 watts of clean, punchy audio power to elevate your home theater or hi-fi setup.

## Overview

The Fosi Audio M03 is a compact yet powerful 200-watt mono subwoofer amplifier featuring the advanced Texas Instruments TPA3255 chip. It offers switchable modes for full-frequency or dedicated subwoofer use, delivering ultra-low distortion and clean sound quality. Designed for home theater and hi-fi systems, it includes a 32V/5A power supply and precise bass control, making it a versatile and easy-to-integrate audio upgrade.

## Description

desertcart.com: Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply : Electronics

Review: A powerful driver for a sub woofer - UPDATE: The TAPE out hookup I mentioned below worked great for levels, but TAPE out is, by design, not controlled by the volume knob on my Pioneer receiver, so I had to constantly adjust two knobs, one under my desk at the sub, so not ideal. The solution? I just added a $25 preamp before the FOSI to have excellent subwoofer levels from the Pioneer subwoofer output, plenty of signal now at half volume or less on both the preamp and the FOSI main amp. The preamp is also a simple and excellent little device. https://www.desertcart.com/dp/B0945RFJ6Z?ref=ppx_yo2ov_dt_b_fed_asin_title I went with this preamp instead of some units, like the FOSI preamp, because it does NOT do any RIAA equalization that I did not want to add to the mix. I bought this FOSI to get my 24 year old KLH subwoofer running again. I am very pleased. I was able to remove the plate amp assembly and leave the SW box sealed on the back as it has always been, by the plastic box that had housed the circuitry. I might mount the FOSI in this plastic recess, but for now it sits atop the SW cabinet and if its rubber feet keep it from walking off I will just leave it there for ease of reaching the controls. This tiny powerhouse is driving the 8" KLH speaker to make better sounds and deep vibrations, than it has for years. Gone are the occasional deep pop and rattle sounds that I had thought might mean the speaker cone itself had deteriorated. It turns out the old cone is just fine. The KLH built in amp had apparently been slowly cooking its circuit board for a long time before it gave up completely last week. It looks like a bulging cap and some burned resistors... maybe I will fix that board someday. One word of warning. I was driving the old KLH ASW 100 powered subwoofer with an RCA Y-cable from the low level sub output RCA jack of a 20 year old Pioneer home theater amp. It turns out that the signal level on that jack is too low to get more than just a faint response from this FOSI, even turned up to the max. So don't assume this will be a direct replacement if you have that kind of subwoofer hookup. I ended up driving this FOSI with a dual RCA cable from the tape record outputs of the Pioneer, and I am getting loud, clear and rumbling bass from the FOSI at only about four clicks of the volume knob. The FOSI volume and freq cutoff controls have a nice, subtle, detent feel.
Review: Great AMP - The Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier impresses with its compact size and powerful performance. With 200 watts of output power and the TPA3255 amplifier chip, it delivers crisp and clear audio, especially in the lower frequency range. Its mini mono-channel design makes it versatile for various audio setups, whether for home entertainment systems or car audio. Overall, it's a solid choice for those seeking high-quality audio amplification in a compact package. The base sounds great in my tv room

## Features

- Subwoofer Amplifier and Full-Frequency Mono Amp: The audio amplifier offers versatile functionality with two modes. Switch to PBTL mode to use it as a full-frequency mono amplifier for driving passive speakers and powered subwoofers. Switch to SUB mode to use it as a dedicated subwoofer amplifier for driving passive and powered subwoofers.
- Advanced Audio Technology: The audio receiver utilizes the Texas Instruments TPA3255D2 chip, featuring an advanced integrated feedback design and proprietary high-speed gate driver error correction (PurePath Ultra-HD). This technology ensures ultra-low distortion across the audio band, delivering superior audio quality.
- High-Efficiency Power Output: The power amplifier provides high-efficiency power output up to 200 watts. It can deliver 150 watts RMS into 4-ohm loads or 120 watts into 8-ohm loads. (Note: The package includes a 32V/5A power supply, but a more powerful power supply is needed to achieve the maximum power output.)
- Home Hi-Fi Amplifier with Clean Sound Quality: The home stereo receiver is designed for home Hi-Fi systems, offering clean sound quality. It features a built-in low pass filter for 20-300Hz subwoofers with SUB frequency control, making it an excellent amplifier for driving any bookshelf speaker or subwoofer.
- What You Get:M03 amp x1, 32V/5A power adapter x1, and user manual x1.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07VHG2LR9 |
| Best Sellers Rank | #55,935 in Electronics ( See Top 100 in Electronics ) #332 in Audio Component Amplifiers |
| Brand | Fosi Audio |
| Customer Reviews | 4.4 4.4 out of 5 stars (760) |
| Date First Available | August 1, 2019 |
| Item Weight | 2.4 pounds |
| Item dimensions L x W x H | 5.12 x 4.13 x 1.37 inches |
| Item model number | M03 |
| Manufacturer | Fosi Audio |
| Maximum Supply Voltage | 32 Volts (DC) |
| Minimum Supply Voltage | 24 Volts (DC) |
| Mounting Type | Surface Mount |
| Number of Channels | 1 |
| Output Power | 150 Watts |
| Package Type Name | Box" or "Case |
| Product Dimensions | 5.12 x 4.13 x 1.37 inches |
| Voltage | 32 Volts |

## Product Details

- **Item dimensions L x W x H:** 5.12 x 4.13 x 1.37 inches
- **Manufacturer:** Fosi Audio
- **Maximum Supply Voltage:** 32 Volts (DC)
- **Minimum Supply Voltage:** 24 Volts (DC)
- **Voltage:** 32 Volts

## Images

![Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply - Image 1](https://m.media-amazon.com/images/I/51zTVamBsHL.jpg)
![Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply - Image 2](https://m.media-amazon.com/images/I/61CjGp0labL.jpg)
![Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply - Image 3](https://m.media-amazon.com/images/I/61EiaNQLMJL.jpg)
![Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply - Image 4](https://m.media-amazon.com/images/I/61p8oyAMBtL.jpg)
![Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier Mini Mono Channel Audio Power Amp for Home Theater Full-Frequency and SUB Bass Switchable with 32V/5A Power Supply - Image 5](https://m.media-amazon.com/images/I/71GJFGepqmL.jpg)

## Questions & Answers

**Q: If the power going in to this unit is 32v 5amp = 160 watts. How is this unit rated 300 watts?**
A: I tested the continuous wattage output using the 32v 5amp supply that comes with it.  I get 50 watts driving 8 ohm, 100 watts driving 4 ohm and 200 watts driving 2 ohm.  I tested with a scope and sine wave.  You get about 20 volts RMS before the sine wave starts to square off at the peaks.  The 50 watts at 8 ohms is surprisingly loud but my 8 ohm speaker is very efficient Electrovoice EVM15 in a Thiel box.

**Q: I can't seem to fine the rms watts. does anyone know the true specs? power at 2 ohms, at four ohms. peak does not mean much.**
A: I put it on an oscilloscope and fed it a sine wave across a 2 ohm, 4 ohm and 8 ohm load resistor.  Using the power supply that it comes with this unit (32V 5A) I see the sine wave start to clip right around 20 volts RMS.   It works out to  50 watts with an 8 ohm load, 100 watts with 4 ohm load and 200 watts with a 2 ohm load.

**Q: What is the maximum voltage and current can be used as it comes with 32VDC at 5 amp.**
A: The power supply current rating of 5A is not quite enough to get the maximum rated output, but it doesn't fall short by much. There are tradeoffs with duty cycle, thermal management, equipment life, program spectral characteristics, etc. but they don't really amount to more than giving precision to common sense. All you need to know is that you can always use a higher current supply without any concern. A 10A supply will run cooler, longer, and cleaner. It is the voltage that has to be in bounds and for this chip TI specifies the working range to be 24-35V and the maximum power to be 300 Wrms. If you want to upgrade get a 36V unit rated over 300 watts, e.g. Mean Well MW LRS-350-36 (9.7A) AND turn the voltage down to 35V or less.

**Q: If using as a full-frequency mono amp to a passive speaker, can the RCA output still go to a powered sub with the frequency control for the sub only?**
A: Yes,

## Customer Reviews

### ⭐⭐⭐⭐⭐ A powerful driver for a sub woofer
*by G***S on December 18, 2024*

UPDATE: The TAPE out hookup I mentioned below worked great for levels, but TAPE out is, by design, not controlled by the volume knob on my Pioneer receiver, so I had to constantly adjust two knobs, one under my desk at the sub, so not ideal. The solution? I just added a $25 preamp before the FOSI to have excellent subwoofer levels from the Pioneer subwoofer output, plenty of signal now at half volume or less on both the preamp and the FOSI main amp. The preamp is also a simple and excellent little device. https://www.amazon.com/dp/B0945RFJ6Z?ref=ppx_yo2ov_dt_b_fed_asin_title I went with this preamp instead of some units, like the FOSI preamp, because it does NOT do any RIAA equalization that I did not want to add to the mix. I bought this FOSI to get my 24 year old KLH subwoofer running again. I am very pleased. I was able to remove the plate amp assembly and leave the SW box sealed on the back as it has always been, by the plastic box that had housed the circuitry. I might mount the FOSI in this plastic recess, but for now it sits atop the SW cabinet and if its rubber feet keep it from walking off I will just leave it there for ease of reaching the controls. This tiny powerhouse is driving the 8" KLH speaker to make better sounds and deep vibrations, than it has for years. Gone are the occasional deep pop and rattle sounds that I had thought might mean the speaker cone itself had deteriorated. It turns out the old cone is just fine. The KLH built in amp had apparently been slowly cooking its circuit board for a long time before it gave up completely last week. It looks like a bulging cap and some burned resistors... maybe I will fix that board someday. One word of warning. I was driving the old KLH ASW 100 powered subwoofer with an RCA Y-cable from the low level sub output RCA jack of a 20 year old Pioneer home theater amp. It turns out that the signal level on that jack is too low to get more than just a faint response from this FOSI, even turned up to the max. So don't assume this will be a direct replacement if you have that kind of subwoofer hookup. I ended up driving this FOSI with a dual RCA cable from the tape record outputs of the Pioneer, and I am getting loud, clear and rumbling bass from the FOSI at only about four clicks of the volume knob. The FOSI volume and freq cutoff controls have a nice, subtle, detent feel.

### ⭐⭐⭐⭐⭐ Great AMP
*by C***C on May 5, 2024*

The Fosi Audio M03 200 Watt TPA3255 Subwoofer Amplifier impresses with its compact size and powerful performance. With 200 watts of output power and the TPA3255 amplifier chip, it delivers crisp and clear audio, especially in the lower frequency range. Its mini mono-channel design makes it versatile for various audio setups, whether for home entertainment systems or car audio. Overall, it's a solid choice for those seeking high-quality audio amplification in a compact package. The base sounds great in my tv room

### ⭐⭐⭐⭐⭐ Keep having to buy more of these!
*by S***E on August 9, 2022*

Great little amp. Works exactly as advertised and very easy to use. The amp has an optional adjustable low-pass filter. In PBTL mode, the amp is full-range. In SUB mode, it uses the adjustable low-pass filter. There is no high-pass outputs. If you are using this amp to add a subwoofer to your existing system, your main speakers will be full-range. If you want a true crossover, you will need either passive RCA high-pass filters on your mains amplifier or an active crossover box. For the past few subwoofers I’ve built and enjoyed with this amplifier, I’ve given them away (to great delight of the recipient). So I have to keep buying more. The last one was for a home recording studio with very demanding fidelity requirements. This is the fourth one I’ve purchased. I’ll be starting the design and construction of the accompanying subwoofer over the next few months. There’s no reason to go shopping for a different amplifier. This one has done everything I’ve needed it to do. The next subwoofer might be a stereo pair, and I'm considering a pair of these amplifiers for a matching set.

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*Product available on Desertcart Romania*
*Store origin: RO*
*Last updated: 2026-02-10*