---
product_id: 593516480
title: "Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply"
brand: "fosi audio"
price: "£155.77"
currency: GBP
in_stock: true
reviews_count: 13
category: "Fosi Audio"
url: https://www.desertcart.co.uk/products/593516480-fosi-audio-za3-balanced-stereo-amplifier-home-audio-component-mini
store_origin: GB
region: United Kingdom
---

# 235W max mono power Balanced XLR/TRS input Advanced heat dissipation Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply

**Brand:** fosi audio
**Price:** £155.77
**Availability:** ✅ In Stock

## Summary

> 🎶 Power your passion with precision and style — the Fosi ZA3 amps your audio game!

## Quick Answers

- **What is this?** Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply by fosi audio
- **How much does it cost?** £155.77 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/593516480-fosi-audio-za3-balanced-stereo-amplifier-home-audio-component-mini)

## 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

- • **Customizable Sound Tuning:** Swap op-amps to tailor your audio signature—perfect for the discerning ear craving personalized sonic perfection.
- • **Next-Level Cooling Design:** Upgraded chassis with side vents and dust covers ensures stable, high-power performance without overheating.
- • **Dual-Mode Power Flexibility:** Switch effortlessly between 180W stereo and 235W mono modes to match your audio setup and maximize impact.
- • **Audiophile-Approved Components:** Premium TPA3255 Class-D chip with Japanese and German capacitors delivers pristine clarity and ultra-low distortion.
- • **Pro-Grade Balanced Connectivity:** Balanced combo inputs (XLR & 1/4" TRS) slash noise and interference for crystal-clear sound every time.

## Overview

The Fosi Audio ZA3 is a compact, high-performance stereo amplifier featuring dual-mode operation with up to 235W output in mono, balanced XLR/TRS inputs for noise-free connectivity, and premium audiophile-grade components. Its advanced heat dissipation system ensures reliable, sustained power, while swappable op-amps allow personalized sound tuning. Ideal for desktop, home theater, and bookshelf speakers, it combines professional-grade features with a sleek, minimal footprint favored by modern audio enthusiasts.

## Description

Product description 2 Channel Amp Amplifying Your Voice, Shaping Our Innovation At Fosi Audio, behind every innovation, there's a story. The birth of the ZA3 amplifier is just such a story, centered around our users. After the launch of the V3 amplifier, we gathered innumerable feedback from passionate audiophiles. They expressed a desire for us to develop an even better amplifier based on V3. Input: RCA, XLR, ¼”TRS;Output: Stereo, Mono Frequency Response:20Hz-20kHz (±0.1dB); Rated Power: Stereo 180W*2 @4Ω;Mono 235W @4Ω Power Adpater Dimensions:7.6 x 3.54 x 1.5in SNR≥106dB; THD<0.006%; SINAD: 89dB Flawless XLR Balanced Input Support Delivers pure sound, initiating a high-definition auditory adventure with unmatched clarity. PBTL Mono Mode Support More power output to elevate your stereo HiFi system to new heights. TI TPA3255 Amp Chip Integrated​ Enabling superior sound and ultra-low distortion across the audio band with Class-D efficiency. 12V Trigger Sync Interface (3.5mm) Easy one-click power management with smooth sync across devices, unifying your audio system. Swappable Op-Amps Compatible with DIP8 dual op-amps. Roll them to get your preferred sound signature. Advanced Heat Dissipation Design Enhanced cooling with larger chassis, whole-body heatsink, and side ventilation with dust covers. Separated Digital & Analog Modules Optimized circuit board layout protects core audio modules from interference for a purer sound. Logarithmic Potentiometer Helps to achieve a fine volume tuning to match human ear's auditory characteristics. Fosi Audio ZA3 Friendly Solution Guide 1. Addressing Functional Issues 1.1 Left Channel and Mono Setup Problems: Mode Selection: Ensure you've selected the correct mode using the switch on the right side of the ZA3. For stereo sound, the switch should be in the downward position; for mono, it should be upward. Cable Connections: Double-check all input and output cables for secure connections. Faulty or improperly connected cables can cause sound issues. Power Supply: Make sure you're using the appropriate power supply for your device. 1.2 Power On/Off Issues: Power Switch Operation: To turn your ZA3 on or off, press and hold the volume knob for 2 seconds. This feature might be different from other devices you've used, so it's important to familiarize yourself with this operation. 2. Enhancing Audio Sound Quality 2.1 Insufficient Power and Sound Output: Volume Adjustment: If the sound is too low, try turning the volume knob clockwise to increase the volume to an appropriate level. Power Supply and Mode: Understand that the power output varies with different power supplies, speaker impedances, and operating modes. Adjust accordingly to achieve the best sound quality. 2.2 Not Meeting Expectations : Audio Source Quality: For better sound, use high-quality audio files and avoid compressed formats like MP3, which can sound worse when amplified. Speaker Placement: Position your speakers at least 30cm away from walls or corners to avoid muddy bass sounds. Subjective Perception: Remember that audio quality can be subjective. Experiment with different audio sources and settings to find what sounds best to you. 3. Overcoming Compatibility Limitations 3.1 Incompatibility with Speakers or System: Check Impedance: Ensure your speakers' impedance is within the 2 to 8 ohm range supported by the ZA3 for optimal performance. 3.2 Lack of Additional Inputs and No Signal Output: Input Options: The ZA3 supports RCA and XLR inputs. It does not have a DAC function, so it won't provide a signal output. Make sure your audio source is compatible with these inputs. 3.3 Power Adapter Size: Adapter Purpose: The 48V/5A power adapter is designed to meet the higher power requirements of the amplifier, ensuring it delivers its full potential. Its larger size is necessary for this purpose. Note: The product doesn't support Bluetooth. Crafting Your Dream Audio System ZA3 TB10D V3 V1.0G ZD3 P4 Q6

Review: Very satisfied but watch out for setup traps - I was replacing an older NAD integrated amp that I really liked. Decided to go class D amp for a replacement. WAY smaller. MUCH less expensive, and this unit has all the functionalities I was looking for at an incredible price (I bought mine for about $130 each on desertcart. Will be using two in mono mode. At first I thought they were defective. PAY ATTENTION TO THE MANUAL THAT WARNS YOU TO CONNECT ALL CABLING BEFORE YOU INSERT THE POWER CONNECTION. If you power the device first, then attach cables, it won't work at all until you detach the power cable and reinsert it. This is no fluke. It happened several times. Attach ALL cabling first, then insert the power connection. Secondly, if you're running it in mono mode the inputs for both units are inserted into the RIGHT side on the rear of the unit. The left channel is disabled in mono mode. This is all spelled out in the manual but it's counter-intuitive at first. As for sound, I'm pleased. I'm sending Tidal or Spotify digital signals to a Fosi ZD3 via bluetooth (works perfectly). The ZD3 is the DAC and connects to the paired Za3s. My speakers are very modest, a HSU powered sub that I've connected to the ZD3 (not the ZA3). Main speakers are HSU HB1 mk2. The ease of use with my iPhone is just fantastic. Essentially any song I want is at my fingertips. Sound quality is very good to my untrained ears. I'm very happy with this purchase. These amps have more than enough power to drive these smaller speakers even at higher volumes than I'd ever naturally want. The fit and finish of the amps is very good. No noise in the volume knob at all but I leave them in a fixed position adjusting volume either at the ZD3 "preamp" or even more commonly with my iPhone volume controls. I've been buying / building stereo equipment for about 55 years. I'm a huge music fan, but I can't hear all the mumbo-jumbo the experts can. I just know these are great little amps for an incredible price, and even one would work nicely in stereo mode. Very happy. Will see how they stand up to time and use.
Review: very good studio solution for passive speakers - stylish and powerful and versatile. good connectivity. light, and thats nice sometimes compared to analog amps, also nice price for what you get

## Features

- Dual-Mode Innovation: This new generation mini amplifier offers both stereo and mono modes, adapts flexibly to your diverse needs, allowing seamless mode switching. In stereo mode, it delivers a robust output of up to 180W, while in mono mode, the power soars to a maximum of 235W. Pair two ZA3 units in mono configuration to create a powerful audio system, significantly enhancing your listening experience
- Richer Connectivity: Debut amplifier with balanced input and trigger in, the ZA3 features a balanced combo audio signal input connector supporting both XLR and 1/4" TRS plugs. This design minimizes interference and reduces noise floor. The 12V trigger-in connector enables synchronization with other devices, streamlining the process of turning on/off without individual operations
- Audiophile-Grade Components: The ZA3 features the TPA3255 high-end Class-D amp chip and utilizes premium Japanese NCC, ELNA, and German WIMA capacitors, and Japanese Sumida inductors for exceptional audio quality. With a SINAD rating of up to 89dB, an SNR of up to 106dB, and a low noise floor of only 150μV, it delivers exceptional clarity and low distortion
- Advanced Heat Dissipation: Based on V3's groundbreaking heat dissipation design, we upgraded ZA3's cooling system by featuring a larger chassis, moving vents to the sides, and adding dust covers to achieve better ventilation for a sustained and stable high power output
- Enhanced Scalable Fun: Personalize your audio experience with the op-amp rolling feature! The ZA3 stocks five swappable op-amps for left and right channel outputs, balanced input, and subwoofer output. Experiment with compatible DIP8 dual op-amps such as Sparkos SS3602, MUSES02, OPA2604, OPA2134PA, OP249, AD827, RM4558, LM4562, LME49720HA, etc. to fine-tune your sound to perfection

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0CLP4T5L7 |
| Best Sellers Rank | #6,622 in Electronics ( See Top 100 in Electronics ) #20 in Audio Component Amplifiers |
| Brand Name | Fosi Audio |
| Customer Reviews | 4.6 out of 5 stars 1,186 Reviews |
| Included Components | Fosi Audio ZA3 Power Amplifier x1；48V5A Power Adapter x1；User Manual x1 |
| Item Dimensions | 6.1 x 7.24 x 2 inches |
| Item dimensions L x W x H | 6.1 x 7.24 x 2 inches |
| Manufacturer | Fosi Audio |
| Maximum Output Power | 235W |
| Maximum Supply Voltage | 48 Volts (DC) |
| Minimum Supply Voltage | 24 Volts (DC) |
| Model | ZA3 |
| Mounting Type | Surface Mount |
| Number of Channels | 2 |
| Output Power | 235 Watts |
| Package Type Name | Cardboard Box |
| Part Number | ZA3 |
| Specification Met | FCC |
| Unit Count | 1.0 Count |
| Voltage | 48 Volts |
| Warranty Description | 24-month manufacturer |

## Product Details

- **Item dimensions L x W x H:** 6.1 x 7.24 x 2 inches
- **Manufacturer:** Fosi Audio
- **Maximum Supply Voltage:** 48 Volts (DC)
- **Minimum Supply Voltage:** 24 Volts (DC)
- **Voltage:** 48 Volts

## Images

![Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply - Image 1](https://m.media-amazon.com/images/I/51XgZUlMEQL.jpg)
![Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply - Image 2](https://m.media-amazon.com/images/I/7175MjuXASL.jpg)
![Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply - Image 3](https://m.media-amazon.com/images/I/713BlqtwMhL.jpg)
![Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply - Image 4](https://m.media-amazon.com/images/I/714J9YgFoiL.jpg)
![Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply - Image 5](https://m.media-amazon.com/images/I/71SJfec1-vL.jpg)

## Questions & Answers

**Q: Is it possible to use the trigger out from the Fosi Audio ZD3 to two pieces of ZA3 amplifiers?**
A: Yes, use a dual 3.5mm male splitter cable to trigger the ZA3 to switch on synchronously.

**Q: How to set up a system using two ZA3 units in mono mode?**
A: - Connect the RCA (XLR) cables to the right-channel RCA (XLR) input ports of the two ZA3 units, and link the speaker wires to the right-channel binding posts.

**Q: ZA3 recommendations for replacing op-amps in mono mode?**
A: If you're using RCA mode, please replace only the right op-amp. For XLR mode, swap the right and XLR channel op-amps.

**Q: No front light on ZA3 though there is light on the ac adapter.**
A: Long press the volume button for 2 seconds to power it on.

**Q: The power on LED light on my ZA3 is dead.**
A: Check if the LED is misaligned with the front panel hole, especially if the op-amp was recently changed. Misalignment could cause the LED not to be visible through the case.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Very satisfied but watch out for setup traps
*by N***O on July 12, 2025*

I was replacing an older NAD integrated amp that I really liked. Decided to go class D amp for a replacement. WAY smaller. MUCH less expensive, and this unit has all the functionalities I was looking for at an incredible price (I bought mine for about $130 each on Amazon. Will be using two in mono mode. At first I thought they were defective. PAY ATTENTION TO THE MANUAL THAT WARNS YOU TO CONNECT ALL CABLING BEFORE YOU INSERT THE POWER CONNECTION. If you power the device first, then attach cables, it won't work at all until you detach the power cable and reinsert it. This is no fluke. It happened several times. Attach ALL cabling first, then insert the power connection. Secondly, if you're running it in mono mode the inputs for both units are inserted into the RIGHT side on the rear of the unit. The left channel is disabled in mono mode. This is all spelled out in the manual but it's counter-intuitive at first. As for sound, I'm pleased. I'm sending Tidal or Spotify digital signals to a Fosi ZD3 via bluetooth (works perfectly). The ZD3 is the DAC and connects to the paired Za3s. My speakers are very modest, a HSU powered sub that I've connected to the ZD3 (not the ZA3). Main speakers are HSU HB1 mk2. The ease of use with my iPhone is just fantastic. Essentially any song I want is at my fingertips. Sound quality is very good to my untrained ears. I'm very happy with this purchase. These amps have more than enough power to drive these smaller speakers even at higher volumes than I'd ever naturally want. The fit and finish of the amps is very good. No noise in the volume knob at all but I leave them in a fixed position adjusting volume either at the ZD3 "preamp" or even more commonly with my iPhone volume controls. I've been buying / building stereo equipment for about 55 years. I'm a huge music fan, but I can't hear all the mumbo-jumbo the experts can. I just know these are great little amps for an incredible price, and even one would work nicely in stereo mode. Very happy. Will see how they stand up to time and use.

### ⭐⭐⭐⭐⭐ very good studio solution for passive speakers
*by J***Z on April 8, 2026*

stylish and powerful and versatile. good connectivity. light, and thats nice sometimes compared to analog amps, also nice price for what you get

### ⭐⭐⭐⭐⭐ Plenty of power, sounds nice, good support (firmware updates)
*by D***H on March 7, 2025*

Great little amp. My stack is a Wiim amp pro (for streaming and eq), Fosi ZD3 preamp, and Fosi ZA3 with the 48v power supply running in stereo mode. Mostly run from an apple tv sending hdmi to the tv then optical from there. The whole setup was easily under $500. I chose this setup in case I needed more power, I can simply add another amp and run mono, but it's definitely not needed. Runs a pair of Q Accoustic 5020s easily to unlistenable levels in a small/med size room (450sq/ft). I have the whole stack switched with a smart plug and haven't had any issues with powering off or on (unlike my last set of powered Swans speakers which blew up on power up). I was occasionally getting a little pop on power up and also a computerized "bzzzrt" very occasionally during listening. I just googled and found there was a firmware update for the Preamp (no issue with the amp). Just contact Fosi support and they give you the url for the updated firmware. Easy to install with a windows laptop and usb cord. Haven't had either issue since. Really nice to see firmware updates so quickly! So used to products this cheap being treated as "disposable" and not getting real support. I'm very happy with the performance and the support. I think it really helps that there seems to be a lot of love in the stereo community for this and other Fosi products. I hope it continues to get firmware updates in the future. The set looks really clean and very minimal. Used to do the whole rack or shelf system of components, but I'm over it. Most recently, I was using a set of powered speakers because I like not seeing the electronics. But when those failed you basically throw the whole thing away. I eventually had them fixed, but I don't like the idea of a failure being a total loss. So now I like having small separate pieces. I absolutely love the size. Even though the Fosi set looks very nice, I now have my entire multimedia set up hidden behind a small chest and subwoofer as shown in the last picture (please ignore my weird music choice). There is one downer on this product. It has a sub out which is great. But when you connect a subwoofer, it still sends full signal to the speaker outs. At high volumes you can hear the small bookshelf speakers trying to put out bass that's not really needed with a sub. Edit: I forgot my SVS subwoofer has a high pass eq! So now I have the preamp go into the subwoofer and pass through to the amp. The sub out should really be on the preamp not the amp. Weird choice.

## Frequently Bought Together

- Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply
- VANDESAIL XLR Cables, 3ft 2 Pack Microphone Cable, XLR Male to Female Balanced Microphone Cord 3 pin, 3 Foot Short mic Cord Oxygen-Free Copper (OFC) Nylon Braided

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.co.uk/products/593516480-fosi-audio-za3-balanced-stereo-amplifier-home-audio-component-mini](https://www.desertcart.co.uk/products/593516480-fosi-audio-za3-balanced-stereo-amplifier-home-audio-component-mini)

---

*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-05-20*