P3A vs LM4702 AMP's

[ostripper]

what should the idle current be for my lm4702 amp its at 56ma when the meter is going from the + power supply to the amp's + power input

25-30ma per rail for the IC minus your 58 , your + Op device must be biased at 28 -33ma ??

OS

 

[sonnya]

Care to share?

Who are you referring to

 

[digits]

OS's modification...

 

[bra]

LM4702 with good power end sound fantastic - this is high end chip

 

[borys]

bra
Must confirm, that is a good IC. I have made small board and connected to my OPS board with 2 pairs of toshiba mosfets = lovley.

Now a friend of mine have recommended to drive some BJT's with a pair of latFETS so whyn not to give it a try

 

[Tibouchina]

And getting back to the original comparison

LM4702 with good power end sound fantastic.

And getting back to the original comparison .... I think a large percentage of P3A amplifiers may be suffering from a parasitic oscillation on the negative side of a sinusoidal waveform near clipping. You need to drive the amplifier up to just before clipping and look at the output on a CRO. The oscillation frequency is in the MHz range. Quite easy to cure. But this must affect the sound quality, if not fixed.

It is possible to find this also using a detailed spice simulation.

 

[jacques antoine]

Why bother if oscillation occurs only just before clipping?