Fosi Audio ZA3 User Manual
Fosi Audio
Introduction
Thank you for purchasing the Fosi Audio ZA3 balanced HiFi Class-D power amplifier!
The ZA3 is a meticulously crafted high-performance balanced power amplifier designed with users' needs deep in mind. It supports XLR balanced input, offering strong interference resistance and effective noise reduction capabilities. Integrated with the high-end Texas Instruments TPA3255 Class-D amplifier chip, when powered by a 48V PSU and connected to 4Ω impedance speakers, it delivers a rated output power of 310 watts (155 watts per channel) in stereo mode and 235 watts in mono mode. You can also pair two ZA3 amps to create a stereo system.
The ZA3 incorporates a side-vented perforated heat dissipation design, facilitating efficient air circulation and significantly enhancing heat dissipation performance. Internally, it integrates audiophile-grade capacitors, inductors, and resistors, ensuring stable output for high-fidelity audio. Furthermore, the ZA3 boasts a replaceable op-amp design, enabling users to effortlessly roll between various op-amps to tailor their musical experience to individual preferences.
The ZA3 is a mini amplifier designed for audiophiles, and Fosi Audio believes it will take you on a delightful journey into the world of HiFi music.
Product Overview
The Fosi Audio ZA3 amplifier features a compact design with controls and connections on the front and rear panels.
Front Panel Description:
- 1. Input Mode Switch: Allows selection between different input modes.
- 2. On/Off/Volume Knob: Controls power (long press 2 seconds to turn on/off) and volume.
- 3. Mono/Stereo Mode Switch: Selects between stereo and mono operation modes.
Rear Panel Description:
The rear panel includes various input and output ports:
- 4. XLR Balanced Input: For balanced audio source connection.
- 5. RCA Input: For unbalanced audio source connection.
- 6. Active Subwoofer Output: Dedicated output for connecting an active subwoofer.
- 7. MONO Mode Output: Output for mono operation.
- 8. Passive Speaker Output: Terminals for connecting passive speakers (supports banana plug or bare wire connection).
- 9. DC 24-48V Power Input: Port for connecting the power adapter.
- 10. 12V Trigger Input: Allows synchronization of power with other devices.
Certifications visible include CE, FC, and ROHS. The website www.fosaudio.com is also indicated.
Specifications
| Feature | Specification |
|---|---|
| Channel | 2.0 |
| Amplifier Chip | Texas Instruments TPA3255 |
| Input | RCA, XLR |
| Output | Speaker Output (supports banana plug or bare wire connection), Active Subwoofer Output |
| SINAD | 89dB |
| SNR | ≥106dB |
| Dynamic Range | ≥106dB |
| THD | <0.006% |
| Support Speaker Impedance | 2-8Ω |
| Rated Output Power | 48V/5A: Stereo: 155Wx2 @4Ω, Mono: 235Wx1 @4Ω 32V/5A: Stereo: 95Wx2 @4Ω, Mono: 110Wx1 @4Ω |
| Frequency Response | 20Hz - 20KHz (±0.1dB) |
| Voltage Range | DC 24-48V |
Package Contents
- Fosi Audio ZA3 Power Amplifier x1
- User Manual x1
- Power Adapter x1
Operation Guide
Please do not connect the power supply before completing all the connections.
- Prepare your audio source device, the ZA3 amplifier, a 24V-48V power adapter, passive speakers, speaker cables (with banana plugs or bare wires), and RCA or XLR audio cables.
- Insert the RCA or XLR audio cables into the corresponding left and right channels on the ZA3. The red plug represents the right channel, while the white plug represents the left channel. Connect the other end to your audio source device.
- Connect the speaker cables to the left and right channels on the ZA3's speaker output terminals. Please ensure that the speaker cables are correctly connected to the positive and negative terminals.
- Plug the adapter into the DC power input port on the ZA3, then connect the power adapter to the outlet.
- Long-press the power knob for 2 seconds to turn on the ZA3. At this point, the orange power indicator light will illuminate. You can now play music on your audio source device and start enjoying the music.
Note: The subwoofer output terminal can only be used to connect a powered subwoofer!
Setup Instructions
The ZA3 supports stereo and high-power mono modes. In mono mode, the minimum load is set to 2 ohms.
Stereo Mode Setup:
To set up in stereo mode, connect your audio source to the respective left and right inputs (XLR or RCA) on the ZA3. Connect your left passive speaker to the Left Channel Speaker Output and your right passive speaker to the Right Channel Speaker Output on the ZA3.
Mono Mode Setup:
For high-power mono mode, connect your audio source to the respective left and right inputs (XLR or RCA) on the ZA3. Connect both passive speakers to the Left Channel Speaker Output and Right Channel Speaker Output terminals on the ZA3. The minimum load for mono mode is 2 ohms.
12V Trigger Interface:
The ZA3 is equipped with a 12V TRIGGER input interface, allowing it to synchronize power on/off with another device, eliminating the need for tedious individual power toggling. This connection is made via a 12V TRIGGER OUT port on a compatible device (like the Fosi Audio ZD3) to the 12V TRIGGER IN port on the ZA3.
Op-Amp Replacement:
The ZA3 allows for dual op-amps rolling to tailor the audio experience. Follow these steps for replacing the op-amps:
- On the PCBA board, identify the marked positions for the left and right channel op-amps. 'L-OPAMP' indicates the left channel, and 'R-OPAMP' indicates the right channel. Confirm which channel's op-amp needs replacement.
- Use tweezers to carefully remove the existing op-amps. Ensure correct orientation: locate the number 1 marking or the circular/semi-circular notch on the op-amp cover. Align this marking with the position marked '01' on the PCBA board, and then plug the new op-amp into the socket.
- Important: Ensure the op-amp is installed in the correct direction to avoid damage.
Op-amp Identification Details:
- Markings: Components are marked with channel indicators like 'L-OPAMP' and 'R-OPAMP'. Op-amps have a '01 pin' marking.
- Orientation Notches: Op-amps feature a round or semi-circular notch on their cover for correct alignment.
- Number 1 Marking: Some components may have a 'No 1 marking' to indicate orientation.
Precautions
- Before turning on the power for the first time, please set the volume to the minimum level to avoid the risk of sudden loud sounds that could damage the speakers or harm your hearing.
- The ZA3 features volume memory functionality, so when powered on again, it will retain the volume level from the previous shutdown.
Frequently Asked Questions
1. Why is there no sound after all the devices are connected?
- The amplifier is not powered on; please check whether the mode indicator is on.
- The volume of the amplifier is too small; please turn the volume knob clockwise and adjust it to the right level.
- The audio cable is connected incorrectly; please reconnect it according to the steps in the instruction manual.
- The audio source is not playing or muted; please check the audio source equipment.
2. After a successful connection, the sound is abnormal?
- Polarity reversed: Please check if the speaker wires are correctly connected with red as positive and black as negative.
- Poor speaker wire contact: Reconnect or replace the speaker wire. For RCA/XLR cables, reestablish the connections or try using different RCA/XLR cables.
- Amplifier overload: Reduce the volume if the amplifier is experiencing overload.
3. Unable to play properly after connecting the turntable?
- The turntable lacks a built-in preamp: Please check if your turntable has a built-in preamp. The ZA3 does not have a built-in turntable preamp, so you need to connect an external turntable preamp between your turntable and the ZA3. For example, Fosi Audio Box X1, X2, X4, etc.
- Incorrect turntable output mode: Turntables with built-in preamps typically offer both turntable output and line output options. Please select the line output.
If you have any further questions, please contact the Fosi Audio support team via support@fosiaudio.com.
Warranty and Maintenance
Fosi Audio pledges to give a 24-month limited warranty and support from the date of purchase. If you encounter any problem when using our product, please contact our support team at support@fosiaudio.com.
About Us
Fosi Audio designs and builds innovative audio products with all your music in mind. Great sound, simple but elegant designs, high-quality components, and truly useful features are what Fosi Audio pursues. Fosi Audio sincerely hopes you can get as much enjoyment from their products as they've had to create them!
Contact Information:
- Our Website: www.fosiaudio.com
- Amazon Store: www.amazon.com/fosiaudio
- Facebook Page: Fosi Audio
- Youtube Channel: Fosi Audio
- Whatsapp: +86 13716612254
- After-Sales Service and Technical Support Email: support@fosiaudio.com
