Small Class D 5.1 Amplifier Project

[karnalta]

Hello all,

I'd like to build a 5.1 amplifier for my office to take analog signal from my sound blaster card. ATM I have a old logitech Z5500 kit and I have already replaced some speakers by Minx Mini one. I don't need an high fidelity amp I just expect something a bit better than the logitech I have now.

I am a DIY guy but one week ago, I was knowing nothing about audio. And I still don't know very much 🙂

My current project consist of various modules assembly. But I can weld electronic if required.

Here is my first try :



My questions :

- First of all, will it work fine ? 🙂

- I plan to use an active subwoofer, can I output to it an already amplified signal or should I send the raw analog signal ?

- It seem like in 5.1 schema, subwoofer use the center signal but what happen if I listen to stereo music then ? No subwoofer I guest ?

- The TPA3116 module have a gain potentiometer on each, is there a way to add a master volume above them all ? The idea would be to be able to adjust each individually (like decreasing the center) but have a master volume to simple lower the general volume.

Thank a lot if some peoples can take some of their time to give me advises.

 

[Ian Finch]

To begin, I think you may misunderstand the application of uPC1237 and probably other protection chips. In general, overload protection circuits or their IC chip equivalents, are designed to sense excess current in the emitter resistors of class AB or A power amplifier output transistors (not directly suitable for class D) and then switch off a power relay that is inline with the audio output. One tiny IC chip just can't deal with the amps of current flowing to the speakers. Also generally, class D chips already have inbuilt protection - you probably don't need to add any more.

Here's some help: upc1237 application - Google Search
Other Audio Related Projects – BuildAudioAmps

 

[karnalta]

To begin, I think you may misunderstand the application of uPC1237 and probably other protection chips. In general, overload protection circuits or their IC chip equivalents, are designed to sense excess current in the emitter resistors of class AB or A power amplifier output transistors (not directly suitable for class D) and then switch off a power relay that is inline with the audio output. One tiny IC chip just can't deal with the amps of current flowing to the speakers. Also generally, class D chips already have inbuilt protection - you probably don't need to add any more.

Here's some help: upc1237 application - Google Search
Other Audio Related Projects – BuildAudioAmps

First, thank you for your answer.

I haven't dig a lot in class AB / A amplifier as I had summarized that they were power eater, more expensive and destined to high fidelity audio.

I wasn't aware that class D amp board could already include speaker protection (I will check). My thought about the UPC1237 module was that it was intended to avoid that a voltage peak could go to the speaker in case of amp/psu failure.

Any suggestions on my other questions 🙂 ?

 

[karnalta]

After a lot of hours of parsing this forum and google, I ended up with a new schematic that should solve my problem of master volume and 5.1/Stereo subwoofer usage.