High Power Gainclone

[Tenson]

Oops I think I should have posted this here - High Power Gainclone

Thanks

[dfdye]

A bridge/parallel LM3886/LM4780 won't get you half that, unfortunately. My back of the envelope math says you need approximately +/-56V (though I might have done the math wrong) to get 400W into 8 ohms and +/-70 to get 600W. No chip amp that I know of can do those rails (except the LM4702, but that is only a voltage driver, not a traditional "chip" amp)

That being said, I can't really conceive a way to get to 400-600W using just chips. I think you will have to go to a more complex design to get that much power.

David

[tiltedhalo]

You can easily achieve power levels that high and higher, upwards of a thousand watts per channel are possible. Granted with a lot of work.
Not anything agaisnt dfdye my present chip amp produces well over 400 watts per channel and uses LM3875 chips.
Watts are not all volts, oh current must there be..........
PS this is my baby chip amp I am building its big brother now.

[dfdye]

Originally posted by tiltedhalo
Not anything agaisnt dfdye my present chip amp produces well over 400 watts per channel and uses LM3875 chips.

None taken, and upon reconsideration, I am indeed being silly. Knee jerk ohm's law = bad assumptions.

Yea, so ignore my first post, if for no other reason than I screwed up the math (all of the numbers should have been swings, not +/-, not that it matters now)

[dfdye]

So, tiltedhalo, care to share a schematic?

[Tenson]

Indeed, it looks like you have PCB making capabilities. Would it be possible to buy some of the PCB's from you if it looks the best solution?

[tiltedhalo]

If any one wants a copy of schematics or possible boards let me know via E-Mail tiltedhalodesigns@gmail.com
Due to reasons I do not want to go into I do not post full circuits. I reserve full intellectual and physical rights to developed circuits, and would expect them only to be used for non- profit DIY projects.

[phreeky82]

i know sfa about amp design, only built a couple of kits, but could you explain one thing visible from that pic please?

i notice the toroidal->bridge rectifier->filter caps, then a whole bank of caps - what are they doing/what is their purpose?

i've also looked into a way of using typical kit amps in a car but somehow upping the power but it appears the only real way of doing it is a switched power supply, meaning it's probably not really worth it. it's somehow related however, how to get big power amps from low voltage with mega amounts of current available.

chatting to a mate who has been designing some amps (but not of the audio kind), he said

They would also use multi-stage amplifiers, the input sine wave is
amplified and past through impedance transformation networks that changes the amplitude of the wave before it is applied to the next stage of the amplifier, then it is increased further.

means sfa to me

???

[MWP]

I have ran bridged LM3886's at +-41V in a few of my amps.

Keeping them cool was very difficult at the max heat dissipation power point.

I had to use live (not insulated from the LM3886 tabs) fan-cooled heatsinks to remove the heat.
Using mica or other tab insulation gave very early heat protection clipping problems.

Cant remeber exactly what power i was getting out of them though... it was a few years ago.

[sagarverma]

look in to tda7293 for its modular application.