Parrallel/bridged LM4780 ??

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Joined 2004
Hi, i am browsing the chip amp solution and am looking at all possibilities...
TDA72xxx,...
I made some extensive search and didnt find what i was looking for...
So i came to LM4780, 2 channel in parralel and two of theses in bridged...
anyone ever did this ?? that could make a very cheap and very powerfull amp...

anyone?
 
Disabled Account
Joined 2004
wow, thaks guys for the comments...

do you have any pictures ?

what did you used to compensate the dc output, servo, adjustable bias,...

I have all these big toroidal transfos, caps and huge heat sinks...not to mention that big mofo penultimate zen that i build and that i dont use at all ...i could swap in a lot of these LM4780 :D
thanks guys.
 
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Joined 2002
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I did exactly what you said in your first post. I got two LM4780 kits from Audiosector, and set them up in the parallel mode on each chip. Then two boards are bridged (I have a soundcard with balanced output). I don't compensate for DC and there is no input cap. DC offset is 2mV on one channel and 6mV on the other. Have to really be confident of the fact that there is no DC on the input, else it'll cook the speakers...

It's reasonably cheap, very powerful (I estimate around 200 watts/channel) and not too bad-sounding either. The transformers are 440 VA EIs for each channel (this part of the world is still in the EI era), and I added 4700 uF per rail to the Audiosector kit's 1500uF. I had 10,000uF in there earlier, but I prefer it with less capacitance.
 
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