A
alan
Guest
I'm considering building an audio amp using some LM3886's from National.
One thing that slightly worries me is that on one of the plots of
power vs load resistance, it really takes a dump below 4 ohms. I
currently have speakers that dip to three ohms, so I am considering
paralleling two to reduce the load on each. It doesn't mention
paralleling amps in this datasheet, but in another it just sez to match
the gains and put a .1 Ohm resistor between each of the amps.
One question is that the datasheet sez that each amp sees twice the load
resistance, but doesn't each amp actually see a .2 ohm resistance to the
other amp? Will that cause stability problems?
The next question is if there is some kind of a standard trick, using
feedback or other gizmitry, to better load balance the amps and also
reduce the output impedance to nearly zero (or even slightly negative to
undo the effects of speaker cables).
One thing that slightly worries me is that on one of the plots of
power vs load resistance, it really takes a dump below 4 ohms. I
currently have speakers that dip to three ohms, so I am considering
paralleling two to reduce the load on each. It doesn't mention
paralleling amps in this datasheet, but in another it just sez to match
the gains and put a .1 Ohm resistor between each of the amps.
One question is that the datasheet sez that each amp sees twice the load
resistance, but doesn't each amp actually see a .2 ohm resistance to the
other amp? Will that cause stability problems?
The next question is if there is some kind of a standard trick, using
feedback or other gizmitry, to better load balance the amps and also
reduce the output impedance to nearly zero (or even slightly negative to
undo the effects of speaker cables).