Can this amplifier be bridged?

[lalalala]

Hi,

I find this class D amplifier kit on ebay:

TDA8920 CLASS D Audio Power Amplifier AMP Kit 100W X2 | eBay

It seems very inexpensive (if it works). Anyone knows if this amplifier can be bridged?

Thanks.

 

[LAJ]

Probably not

The concept of bridging requires that one of the inputs (of a stereo amp) be inverted. This can easily be accomplished with balanced inputs but its my guess that this amp probably has unbalanced inputs.

 

[lalalala]

You are right. The input has three terminals (-, + and GND), if that is what you mean by "balanced input". What if I connect one input to the - and +? Is that equivalent to bridging it? Thanks a lot.

 

[stratus46]

The concept of bridging requires that one of the inputs (of a stereo amp) be inverted. This can easily be accomplished with balanced inputs but its my guess that this amp probably has unbalanced inputs.

An inverter is a mystery? The limiting factor is output current capabilities.

G²

 

[macboy]

This definitely can be bridged, but you will need to provide an inverted signal at one input (either L or R). The +/-/GND "input" that you see is the connection for the power supply. The input signals are on the little white connector.

If you look up the TDA8920 you will see that it is a 2 x 50 W chip (or 2 x 80 W depending on which datasheet you find), and it can be operated in bridged mode. In stereo mode and 8 ohm load, the output at 0.5% distortion is only 30 W x 2, and rises to 39 W x 2 at 10% which isn't music any more, it's garbage. With 4 ohms, it can do 80 W x 2 at 10% distortion. In mono bridged mode and 8 ohms, it manages 79 W at 0.5% and 100 W at 10%. My point is, don't believe for a second the "100 W x 2" in the auction title. It is a lie. And if they lie about that.... what else? Do you trust them enough to send your money? And do you even want this if it does only 30 W/ch not 100 W?