Upcycling Audio

It has been a very long time since my last audio project, so when in need of a bluetooth capable system it was time for a bit of DIY.

Among the clutter in the garage were most of the pieces that are needed.

• Wharfdale Power Cube 12+ subwoofer without the amplifier, but with it's 12" speaker
• Panasonic surround system tower speakers
• twin cable for speaker leads
• laptop 19v 4A power supply

Total cost so far $0.00

No suitable amp, so I had a look at what is available out there, without breaking the bank.

There are quite a few options, but this one really fitted the bill:- XH-A305 Digital 2.1 Channel Bluetooth Dual TPA3116D2 Power Amplifier Board

You can order it from overseas, but why wait or even pay much more, so it came locally from Amptech for around $30 including shipping and arrived within a few days.

No instructions, and the datasheet available is only for the amplifier chip. Being somewhat suspicious in nature, I checked under the heat-sink to see if the amplifier chips where what they claimed - they were, but the lack of any thermal paste or pad was something that needed attention. I managed to recycle a quantity of thermal paste from the heat-sink I removed from the subwoofer box to beef up the thermal dissipation.

Luckily the connections are labeled, so reasonably simple to follow, especially if you have some experience.

Once the subwoofer was given a little attention, like removing the weighty transformer and rewiring the speaker, everything was quickly connected up, so I applied the power and - nothing.

Check the power supply, it is working and outputting voltage. Check the power out from the onboard socket - nothing. The plug looked to be the right size and fitted well, but was not connecting the center pin at all.

A quick rummage found another candidate, and this time it powered up, with an oriental voice announcing how to pair the Bluetooth. who needs AI or instructions when it can voice guide you :)

There are three pots labeled as STERE, BASS and VOL As expected, VOL controls the volume, and BASS the bass but STERE seems to control the treble response.

Overall it works reasonably well for a very low budget system, but not exactly HiFi to my old ears.

Sometimes product data is blindly copied from the supplier

and some resellers actually check it makes sense

In case you dodn't look closely, what is Tribble ??