LME 49810 with NMOS output stage 1000W @ 4 OHM

[NMOS]

Originally Posted by Th3 uN1Qu3

Well pointed out. I only see a DC protection which will protect the speaker, not the amp... For something to survive any reasonable length of time in PA duty you need an input signal limiter, DC protection, VI limiters and overtemperature protection, at the very least.

ok, thanks

- you need an input signal limiter,

have an input signal limiter, its DSP input board

- overtemperature protection

yes have with 2 step fan control

- VI limiters

I think zener + diode in series should protect the fet for overcurrent ??

[ingenieus]

I've said it before and will say it again - a project like this is not to be undertaken lightly. The transformer needed will be similar to that found in a small arc welder, for instance.

It is most unlikely that you will be driving a single speaker with 1kW. Rather build four 200W amps and drive four speakers. Much easier. Or if you insist on having a big rig, build two 400W amps (the difference between 800W and 1000W is about 1dB).

[sakis]

Originally Posted by NMOS

ok, thanks

- you need an input signal limiter,

have an input signal limiter, its DSP input board

- overtemperature protection

yes have with 2 step fan control

- VI limiters

I think zener + diode in series should protect the fet for overcurrent ??

no zeners and diode will not be enough
sophisticated vi limmiters might
and then Vas needs to be guarded also at this power
then pcb will be twice as tricky
distribution of power /earth in such a large scale cannot be done easy


hear this .... nobody here is trying to kill your diy spirit... just to explain to you that your task is not easy and requires various types of knowledge

( another example is that for a behringer EP4000 there is a team of engineers working for quiet long time ( i also have details available if you want ) trying to do this and prevent every available aspect of error or performance versus cost ) what makes you think that one person can produce similar results in lets say 6 months time ?)

[ingenieus]

Have a look at the datasheet for the LME49830. It has a circuit with PCB layout. While this circuit will not put out 1kW, it will make a lot of noise. The output devices are good for 150W each, so it will go north of 100W with ease. If you add additional MOSFETS, 200W or 400W is within reach.

[kipman725]

Class AB is silly >400W all PA amplifiers I can think of >1kW are class H,G or D

[NMOS]

Originally Posted by sakis

( another example is that for a behringer EP4000 there is a team of engineers working for quiet long time ( i also have details available if you want ) trying to do this and prevent every available aspect of error or performance versus cost ) what makes you think that one person can produce similar results in lets say 6 months time ?)

can you send me details ?