How to bridge a TDA7377 or Similar Amp?

[dubstar]

Hi there,

I've been doing some research on a problem aI have and I hope I have come to the right place.....the conundrum.....

I have an early VW and it has just one central 4x6" speaker. I have a retro sound stereo (it has RCA outputs for 4 channels +4 speaker level outputs) and at the moment I am just driving the speaker off the left channel, so I don't get the full stereo sound.

What I would like to do is build a 2 channel amp that I can then bridge to 1 summed/combined output channel, so that my speaker gets the 'whole' sound, as well as a bit more power.

Requirements:

- It has to be light and compact
- 12V DC power
- Fairly easy to solder up (I'm an amp virgin, although I have done otehr projects)

I have been on ebay and see the following kits.....is there a way I can modify these to give me bridgeable channels?

Finished TDA7377 2 0 BTL 2CHANNEL Power Amplifier Board DIY DC AC Power Supply | eBay

TDA7377 Power Amplifier Board DIY Kit BTL Mode for Car Amp AC or DC Single Power | eBay

Thanks in advance for your help.

 

[PetruV]

You cant bridge bridged amps,but you can use something else,like my favorite tda2003

 

[dubstar]

Do you have a link to a kit/schematic for a 2channel bridgeable circuit?

 

[AndrewT]

Use a summing stage.

The two Stereo outputs feed a two input inverting opamp and give you a summed mono output to feed to one channel, or more.

But a summing stage doubles the signal level, it really does ADD the two signals together.

If you need the same "level", the summer needs a gain of -6dB for each input to give the same output level. That is easy, you just half the value of the feedback resistor.