How to bridge stereo IC amplifier

[Roy Low]

Hi there all,

I have a couple of commercially built Stereo amplifiers, using the Philips TDA 1521 stereo modules.
I have built a Miditzer Theatre organ, and need a little more audio power.
Now, can I use these amplifiers in bridge mode (and how to go about it)?

I have read the forum article, which suggests needing a balanced input. This should'nt be a problem. as I have balanced transformers from my professional days in broadcasting (hey, they are simple to use !)

Thanks all

Roy Low

 

[Roy Low]

Solution to bridgeing TDA amplifiers

After I picked up an item about using balancing transformes on the inputs of the stereo amps., I set up the system using a smallish balancing transformer on the two inputs, and connected up the speaker across the + speaker inputs.
It worked !!
I used a twin beam 'scope to check both channels, to set the balance between the halves. At 40 Hz, the phase showed clearly, so I matched the levels.
I then got it running, and went away for a few hours.
It is loud and has a very open sound.
As I failed to destroy the unit, I have fitted then to my Midi Wurltizer and am impressed.

Thanks for the leads folk,

Roy Low