You can DIY a for Bluetooth speaker, just need a battery(this product doesn't include battery), two speakers, and a case then you will get a nice for Bluetooth speaker. 2 x Power Amplifier Board. Output 5W + 5W dual‑channel stereo, support USB sound card, no driver, just plug and play.
eBay
Douk Audio NS-14G HiFi 2.1 Channel Bluetooth TPA3116 Digital Amplifier Stereo Receiver Desktop Audio Subwoofer Amp
Aliexpress UK
Better Sound: With this audio amplifier board, you can enjoy better sound quality with low noise as well as low distortion. Item Type: Audio Amplifier Board. 1 x Audio Amplifier Board. Output Power: 5W.
eBay
Fosi Audio Bluetooth Sound Power Amplifier 2.1 Channel Amp Audio Reciver for Speaker Subwoofer 165Wx2 +350W BT30D PRO
Aliexpress UK
Features 1. Our power amplifier board is designed with 2.0 channel digital stereo and signal-to-noise ratio of 100 decibels. The power amplifier board can well ensure high‑quality sound. Application: Audio Power Amplifier Board is applied to computers such electronic devices to create a better experience with amplified sounds.
eBay
Fosi Audio 48V 5A/48V10A/36V 6A DC Power Supply Charger Home Theater Amplifier Power Adapter For Audio Amplifier Input 100-240V
Aliexpress UK
50W + 50W 2.0 HIFI level digital power amplifier board. Item Type: Digital Amplifier Board. 1 x Digital Amplifier Board. Output Power: 50W + 50W. If you are satisfied with our service, pls.
eBay
Car Audio Amplifier 360W DSP Audio Power Amplifier 6channel For 16pin android head unit android stereo plug play 12v
Aliexpress UK
Onboard TDA2030A audio power amplifier chip. mono 18W amplifier circuit design. with small size, large output power, distortion and other characteristics. And has an internal protection circuit. the chip has been the main pin leads, you can directly enter the audio signal.
eBay
Woopker Digital Amplifier AK55 Audio Bass Audio Power Bluetooth Home Amplifier Hifi FM Auto Music Subwoofer Speakers USB SD Mic
Aliexpress UK
NS8002 3V–5V DC Mini 3W Mono Amplifier Module. 1 × NS8002 3V–5V DC Mini 3W Mono Amplifier Module. Output Power Up to 3W. Amplifier IC NS8002. An economical option for adding mono audio amplification without sacrificing performance.
eBay
S-299 Mini 4.1 Audio Stereo Power Amplifier BT Portable Car and Home Dual-use 4*40W Remote Control Audio Amplifier
Aliexpress UK
4 Inputs: Equipped with 4 inputs, BT, AUX, USB flash drive, and USB sound card. Easily connect wirelessly via BT, or through AUX input to your TV, computer, or sound device. Support for USB flash drive and USB sound card input allows seamless playback of music files or computer sound for a premium sound experience.
eBay
2-5 Tier Audio Rack 4 Colors Amplifier Bracket E1 Grade Audio Shelf Speaker Stand For Home Theather Amplifiers Storage DJ Studio
Aliexpress UK
Output Power: 30W (7MHz 13.8V). Wide Application: This amplifier module is mainly used in small signal amplification, audio signal amplification, motor drive and so on. High Accuracy: The high accuracy and sensitivity of the low frequency power amplifier module make the operation more precise and safe.
eBay
Douk Audio NS-10G Mini Bluetooth 5.0 TPA3116 Digital Power Amplifier HiFi Stereo Audio Amp USB Sound Card 50W*2
Aliexpress UK