Can 2 audio amp ICs be used on 1 speaker for more volume?

[kerryandray]

Silly question, I know.   But can 2 audio amp ICs (like the one watt TDA7052) be used at the same time on the same speaker...using the same signal source...to get more power/volume?

I read something about amps (like full amplifiers...not little IC chips) that can be "bridged" into one to feed a single speaker.  Can this be done with amplifier chips like the TDA7052  or LM386?

Ray

[anotherjim]

Yes, any 2 similar amps can be used. One is driven at opposite polarity so you get a push-pull alternating across the voice coil. This doubles the voltage swing which doubles the current and quadruples the power available. The amp chips and power supply have to handle the extra power.  If it exceeds the power handling, you can still do it by using a higher speaker impedance so in some circumstances, what may be ok with an 8ohm speaker with a single chip might only manage bridge mode with a 16ohm speaker for x2 power increase.

[antonis]

A simple bridged audio amplifier..
(R_L represents voice coil's impedance..)

[kerryandray]

Wow.  Cool.  Thanks!

[Marcos - Munky]

Another example: http://www.runoffgroove.com/littlegem.html

Also, be aware of the current draw. A single 386 is enough for draining a battery kinda fast. Fow two bridged 386s, I'd surely go with a dc adapter.

[kerryandray]

Another example: http://www.runoffgroove.com/littlegem.html

Also, be aware of the current draw. A single 386 is enough for draining a battery kinda fast. Fow two bridged 386s, I'd surely go with a dc adapter.

Cool, thanks!  I'm going to try to put two TDA7052 chips together for the danelectro honeytone amp in my travel guitar.  I'm trying to get more clean volume.

I have 6 AA batteries to get the 9v.  It'll last fairly long with even with two chips I'd think...

[anotherjim]

Ordinarily, I'd be wary of boosting power x4 to a small speaker, but you do have a special case. You want to play clean and you have an all in one package and can keep it under control. So its actually the doubled voltage swing on the speaker that's more useful since that determines how close to clipping the signal in the chips can get for a given volume.
I think it should work ok and with clean playing, I don't think the battery consumption will be that much more.

[tonyharker]

Sorry but you can't bridge two TDA 7052 chips in this way as they are already bridge amplifiers. If you try they will be destroyed.

[anotherjim]

Yes, I failed to notice the switch to the TDA 7052 - they are bridge amplifiers - and only rated to 1W at that.

[kerryandray]

Sorry but you can't bridge two TDA 7052 chips in this way as they are already bridge amplifiers. If you try they will be destroyed.

Yes, I failed to notice the switch to the TDA 7052 - they are bridge amplifiers - and only rated to 1W at that.

You are both correct.  The TDA7052 does not seem to work in this configuration.  I've sent away for some different ICs to play with.

Thanks all!