eBay Bluetooth amplifier questions?

Off-topic Chatter
1

Hey all,
I have an old 30Wx2 Aiwa shelf system I bought a couple of decades ago. The speakers sound great, but the main amplifier unit is huge, housing a dual cassette deck, and CD changer, neither of which work, or are needed. I only use the unit for the line-in function, to play music from my phone. I would like to convert this unit over to run from an external amplifier with Bluetooth.

I’m looking at this unit on eBay:
https://www.ebay.com/itm/12V-30W-2-Bluetooth-4-2-Receiver-Stereo-Audio-Amplifier-Board-full-function-USB/183413469911

I’d like to use this to eliminate the bulky amplifier unit, while gaining the Bluetooth connectivity. (Making a poor-man’s bluetooth speaker out of spare parts.)

Does anyone have any experience with this style board? Advice or suggestions?

And what is the “Key” connector on top of the board for?

2

This is the model deck I have. One of the first nice things I purchased for myself as a teenager. Sounds great, just a lot more bulky than necessary.

3

I would recommend getting a TPA3118 chip or similar amp, its pretty good. I personally use this one - 2017 Nobsound Mini Bluetooth Digital Amplifier Hi-fi Stereo High-power Amp 50w×2 for sale online | eBay with some bookshelf speakers and it works great. Check your speakers power rating. Also you might be able to find this amplifier cheaper on aliexpress.

4

Not fast enough cyclops beat me ;-)

Better to go with some TPA3118 or TPA3116 and verify that the board use film capacitors on the output filters (easy to spot : they are way bigger than the ceramic ones)

Can't comment on the Bluetooth part as i don't use that ...

5

:smiley:

These amps are like the BLF version of the much more expensive brands.

6

Yeah, many dirt cheap Class D (which is high frequency PWM) amplifier boards out there.
Even nicely built in an aluminium housing they’re not expensive.
Get a Meanwell clone constant voltage mains switching PSU and you have better sound than that plastic lump of Aiwa. :wink:
Cheap boards out there for 24 Volts too.
Banggood has some too, also with Bluetooth and buttons for next / previous track and volume etc…
Great for portable too, high efficiency due to PWM technology.

Audio is / was a hobby of mine, and i’m always impressed with the sound those little boards provide, especially on a regulated PSU.
Especially the reproduction of the lowest frequencies and dynamic response are impressive, compared to old tech amps.

…you can save money to buy some proper speakers… :wink:

7

I used to stop by the local thrift store once or twice a week. I picked up a number of pairs of good used bookshelf speakers for $20-30/pair. I’m using them with TPA3116/8 and TDA7498 boards and old laptop power supplies. They make for a nice sub-$50 audio setup. I don’t use bluetooth, though, so no advice there.

Diyaudo.com is a good place to avoid if you don’t want another “budget” electronics hobby.

8

If possible check out Parts Express. They have small amps that are already bluetooth capable

9

I ended up purchasing this unit:

Uses the TPA3116 amplifier at 50W per channel.

https://www.ebay.com/itm/TPA3116-50W-50W-Bluetooth-Sound-Decoder-Infrared-TF-Card-Board-Remote-Control-/173518302459

Paid a bit extra to get one from a US seller to avoid the wait. I liked having the optional MicroSD/USB slot. Not sure if I’ll ever use them, but seemed like a cool option.