Download the PDF format of this manual：
S328 User Manual 2024-03-15.pdf
Welcome to use digital voice amplifier, its capacity of lithium batteries can reach to 4000mAh. With double endurance and long standby capacity, it's suitable for teaching, meeting, training, tour guide, singing, square dance, sales promotion, outdoor activities, etc. Please read the manual carefully before using, so that you can operate the voice amplifier correctly and get ideal performance.
Product functional features:
1.FM radio function, with FM wireless microphone to achieve wireless amplification.
2.he built-in capacity of voice amplifier is 2000mAh or 4000mAh.
3.Equipped with mainstream USB-C charging port.
4.Support TF card, U disk play, AUX-in, support MP3, WMA, WAV files, support cycle play. Computer speaker function, it can transmit audio through USB port.
5.Clear and accurate voice tips for mode switch.
6.Memorizing the status and playback location, enter the state before shutdown automatically every time you turn it on.
7.Digital amplifier technology, 5W rated power, 10W maximum peak power.
Function map:
Keys and Ports instruction：
| Mode | In power-on mode, short press to switch mode, mode switching sequence: MP3 mode (U disk) →MP3 mode (TF card) →AUX mode →radio mode →recording mode→ standby mode →USB sound card mode; Some modes will be skipped when the relevant functional interfaces are not in use. |
| Pause/Play Search radio channel | In the MP3 and USB sound card mode, short press to pause (FM is to mute), short press again to play (FM is to cancel mute). In the recording mode, short press to start recording and short press again to pause recording, long press to stop recording and play the recording file. In FM mode, long press to search radio channels. |
| Next | In MP3 Mode, short press to play the next song, long press to fast forward, and in FM mode to play the next radio channel. |
| Previous | In MP3 Mode, short press to play the previous song, long press to fast backward, and in FM mode to play the previous radio channel. |
| Folders | In MP3 mode, switch between folders of U disk or TF card; in FM mode for FM recording and recording exit |
| Cycle | MP3 cycle mode switching: three ways of cycle are single loop, directory loop and all cycle; In the standby mode, short press to light the LED screen |
| Mic-in | 3.5mm microphone interface, in standby mode, insert microphone to amply; in recording mode, insert microphone to record. |
| Aux-in | 3.5mm audio interface, support music play, automatically switch to AUX mode when audio cable inserted. |
| USB Port | Insert U disk to play MP3 file automatically, or connect to a computer, to read and write U disk through a computer. |
| TF Card Port | Insert TF card to play MP3 file automatically, or connect to a computer, to read and write TF card through a computer. |
| Charging Data Port | The charging interface supports a 5V mobile phone charger and computer USB port; Connecting the port to a computer, it will be a USB sound card speaker. You can read and write USD disk or TF card through a computer. |
 | Dial Volume Switch | Rotating the dial can switch on/off the amplifier and adjust the volume. Rotate the switch counterclockwise (push up) to turn on the amplifier and increase volume, rotate the switch clockwise (pull down) to decrease volume till turn off the power. |
LED digital screen illustration:
1.Press "mode"
key to switch to "Standby mode", display status like this:
2. Short press "cycle" key
till the LED screen becomes light, display status like this:
3. In "standby mode" insert TF card or U disk to "MP3 mode", display status like this:
4. In "standby mode" insert AUX cable to switch to "AUX mode", display status like this:
5. Through USB-C charging port to connect computer, display status like this:
6. Press "mode" keyto "radio mode", display status like this:
7. Press "mode" to "recording mode" display status like this:
Operation description：
1.Power switch: Push up the switch counterclockwise, turn on the amplifier when you hear a "click". Voice broadcast the current mode and the LED screen displays the current mode. Pull down the switch clockwise, turn off the amplifier when you hear a "click". When it is switched off, the amplifier will remember the current mode and automatically load the mode when it turn on the next time.
2.Volume control: Rotate the volume dial to adjust the volume. Push the round button counterclockwise to increase the volume and pull down clockwise to reduce the volume.
3.Microphone amplification: Insert the microphone plug into the MIC interface, and press to switch to Standby mode to amplify. Please wear the microphone well and properly adjust the microphone position and keep about 50cm distance from amplifier to avoid howling.
4.MP3 play: In "Standby mode" insert U disk or TF card saved with audio files in MP3, WMA and WAV formats, it will play the audio files automatically. Short press
/
to switch to next song/previous song, long press/fast forward / fast backward. Short press
switch to single loop, directory loop and all cycle.
5.FM radio: Pull-out the antenna to the longest. Pressswitch to "radio mode". Long press 
can search radio channels automatically and broadcast the first radio channel automatically after searching. Pressorcan switch your favorite channels randomly after searching. Insert TF card and U disk, press
can record the current displaying content, short presscan stop the recording, and the recording file is stored in TF card or U disk. FM receives frequency range: 87.5-108MHz.
6.Aux mode: In "standby mode", through the 3.5mm AUX audio cable, the amplifier can be connected with computers, mobile phones, PAD, MP3，MP4 and other devices, it will switch to AUX mode automatically and the LED screen will display LINE, and it can be used as external speaker at this time.
7.Connect the computer: When you connect the computer through USB-C charging interface, it displays "Hdd" on the LED screen. You can read and write the U disk or TF card inserted in the amplifier at this time. Note that when the U disk and TF card are inserted into it simultaneously, the U disk will be identified preferentially.
8.Recording: When you use the recording function, a U disk or TF card must be inserted and it must be connected to the microphone. Short pressswitch to "recording mode", it starts recording when you short pressand speak to the microphone. LED screen displays the recording time, short pressagain to pause recording. Long pressto save the recording and exit recording mode. You can play the recording file in MP3 mode.
9.Charging: It starts to be charged through USB-C data cable when you connect it with computer USB port, a mobile phone charger with 5V output, or a mobile power supply device etc. The LED screen 
flickers at the speed of 1 time/second when it's being charged. The screen is always lighting when it's 80% . It will be full of charge and the data cable can be removed to stop charging if you continue to charge one hour more. When the flickers two times and stops for 3.5 seconds and flickers again, which shows that the battery power is low, and it will voice a tip "power is low, please charge in time", then please charge it. It takes about 4-6 hours to fully charge it.
Tips and cautions:
1.The pickup head should be covered with a sponge cover, and the microphone is placed 1 to 2 centimeters in front of your mouth when you use microphone to amplify sound. It is suggested that the sponge cover should not be removed, because the sponge cover can weaken the air flow, reduce the noise, and make the voice be clear.
2.This product can only be charged with standard voltage 5V. It does not support all kinds of quick charging. Charging with a voltage higher than 5V may burn the product or fail to charge.
3.Microphone should not be close to the amplifier, and it's better if place the amplifier against the microphone. If howling occurs you can reduce the volume appropriately or enlarge the distance between the microphone and the amplifier. The microphone pickup head should not be grasped by hand, otherwise it will be easily howling because of resonance.
4.When you use it for the first time, or for a long time before you use it again, please keep the amplifier be fully charged to ensure battery life.
5.In order to avoid distortion or damage caused by excessive voltage or current, please do not insert the external sound source signal into the MIC interface.
6.Please don't disassemble, or repair it by non-professional technical personnel. If there are any problems, please contact our company for after sale service
7.In order to prevent the danger of short-circuiting, please keep products or accessories away from water, moisture, rain or splash.
8.Do not use the amplifier in inflammable and explosive areas or in areas where radio equipment is prohibited. When you entering dangerous areas or prohibited areas, power should be turned off to avoid potential safety hazards.
9.Do not use it in high temperature, high pressure and high humidity environment (such as sunshine exposure, stove, heater, humidifier, water pool, etc.). Do not place it or close to dangerous sources (fire source, liquid, explosive, high-speed machinery, etc.) in order to avoid damage and danger.
Product specification：
1.Battery capacity 4000m Ah parameter:
Rated power 5W Peak power 10W
Loudspeaker 3-inch 2ohmic magnetic speaker Frequency response 120Hz-15KHz
Battery 2 x 3.7V/2000mAh lithium batteries in parallel Charging voltage USB/DC 5V 1A
Charging time 4-6 hours Using time 35-38hours
Size 125*92.5*48.5mm Net weight 254.5g
2.Battery capacity 2000m Ah parameter:
Rated power 5W Peak power 10W
Loudspeaker 3-inch 2ohmic magnetic speaker Frequency response 120Hz-15KHz
Battery 3.7 v/2000mAh, 1 lithium battery Charging voltage USB/DC 5V 1A
Charging time 2-3 hours Using time 16-18hours
Size 125*92.5*48.5mm Net weight 208.5g
Packing List：
Voice amplifier *1，3.5mm audio cable *1，USB-C cable*1，Head wear microphone*1，
Hanging rope*1，User manual *1.
Declaration：
Hereby, Norwii declares that the radio equipment type S328 is in compliance with Directive 2014/53/EU. The full text of the EU declaration of conformity is available at the following internet address: http://www.jsnt400.com/downloads/downloads/eu_doc/eu.doc
FCCID：2AXGRVA1
Shanghai Norwii Technology Co., Ltd
Address: No.277 Jinfeng Road, Pudong New Area, Shanghai, 201201, China
Tel: 86-21-51872080
Email: support@norwii.com
Web: www.jsnt400.com
