Add a volume pot to a generic 50W + 50W TDA7429P amp

Thread Starter

Prady5

Joined Jan 13, 2017
3
Hello,
I am a total newbie to electronics and want to build a small portable bluetooth speaker for everyday use. Now, I already have ordered a TDA 7429p amp from ebay(generic) and was s-l300.jpg
wondering it would be cool to add a slick looking volume control to it. I havent decided on speakers yet but basically they would 2"- 3" speakrs of 10-15W RMS. I did googled for some posts but they were either for some different setup or weren't clear enough for me to understand.It would be great if someone can show me exactly where to put the potentiometer and how to wire them.
Thanks
 

crutschow

Joined Mar 14, 2008
23,293
You add the pots at the audio input (for stereo you would want a dual pot).
One end of the pot goes to ground, the other end is connected to the audio signal.
The wiper of the pot goes to the amp input.
For volume you want to use pots with an audio taper (logarithmic), not linear.
 

Thread Starter

Prady5

Joined Jan 13, 2017
3
That has a Bluetooth interface on it with an up/dn Scl/Sda volume control, you're going to have to hack into the main amp inputs to put your own Variable potentiometer on..


Have a look at the datasheet....

https://www.google.co.uk/url?sa=t&source=web&rct=j&url=http://www.st.com/resource/en/datasheet/CD00010664.pdf&ved=0ahUKEwi03qnr2b7RAhWsIMAKHYY-DCAQFggaMAA&usg=AFQjCNFRPD15TxbZPKLcKu0llQeaNvXSOw

I not sure if I can do that. Again, I a total newbie to everything you said. It would be a lot easier if you can just point out where to wire.
 

R!f@@

Joined Apr 2, 2009
9,647
Problem is that without looking at the diagram of the PCB in post #1 one cannot tell for sure.

Main issue is that without looking I cannot tell if that PCB uses a differential signal or a single ended signal from the Bluetooth module.
You can add if the signal is single ended. but still we cannot point that out and is difficult to figure out since the PCB is a two layer type.

From the amp IC data sheet you can see where the volume goes.
 
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