Clipping indicator

[ubituks]

Hello, I want to add clipping indicator for my subwoofer, which is powered by TDA7293 x3 with +-35V.

I've found schematic in Power Amp Clipping Indicator. However, I already got +-12V power supply for opamps so I want to feed clipping indicator with it.

I changed schematic to:

An externally hosted image should be here but it was not working when we last tested it.

But I'm unsure about C1/R14, should they be connected to ground or negative opamp powersuppy(-12V)?

 

[sajti]

But I'm unsure about C1/R14, should they be connected to ground or negative opamp powersuppy(-12V)?

To the ground, as it is in the original schematic. You don't need to use the -12V.

Sajti

 

[ubituks]

To the ground, as it is in the original schematic. You don't need to use the -12V.

Sajti

Well, original schematic feeds opamp from single power supply, thats why it's kinda confusing me. So, anything else should be good, too?

Thanks

 

[JonSnell Electronic]

The design will work best with a single rail supply not + - supplies. Why complicate things!
If you use an opto-isolator in series with the LED, you can use it to compress the input. So when it approaches the level acceptable for your speaker power, it will stop transients and clip the input automatically, unaffecting the sound before overload.
Just a thought. Crown use a system like that to reduce input levels above a calculated level on PA systems.

 

[sajti]

Well, original schematic feeds opamp from single power supply, thats why it's kinda confusing me. So, anything else should be good, too?

Thanks

You don't need to use R8 and D7. Keep every other as recommended in the original schematic.

Sajti