Why would you want one? Buy a stereo pair from one of the usual sources, and knock up balanced line driver around DRV134 (or around a pair of opamps, see http://sound.westhost.com/project87.htm ) to provide the necessary inputs.
DRV134 is a seriously easy chip to implement, the only necessary external components are the supply decoupling capacitors (and, obviously, the +/- 15V power supply). Alternatively, there exist suitable transformers that can do the job, see http://www.shine7.com/audio/bpa300v2.htm
These are both better solutions than the 1-inverting, 1-non-inverting setup described in the application notes.
DRV134 is a seriously easy chip to implement, the only necessary external components are the supply decoupling capacitors (and, obviously, the +/- 15V power supply). Alternatively, there exist suitable transformers that can do the job, see http://www.shine7.com/audio/bpa300v2.htm
These are both better solutions than the 1-inverting, 1-non-inverting setup described in the application notes.
Is there any difference in the above two approaches? i.e. is one approach better than the other? Why?
The LM3886 bridge application note AN1192 suggests using an inverted and a non inverted configuration to bridge. Most people seem to be looking at BPA using DRV134. Is it because they are using 6 LM3886 instead of just 2?
What is the better approach to bridge just 2 LM3886 chips?
I am building a 3+3 channel amp. Each channel will have 2 LM3886 in bridge configuration. So looking for the best approach to bridge.
DRV134 adds to complexity and real estate issues considering that there are 6 amps to be bridged. I am wondering if there is any sonic benefit of taking that approach.
Try the Simplest Ever Bridging Adapter for Amplifiers. Cheap, simple and the result is the same.
I don't see why it should not work at unity gain. On the other hand the LM3886 does not work at unity gain, so that circuit need not work at unity gain either. What use is a BTL power amp with unity gain?
100 Ohm is in most cases smaller than even the tolerance of the feedback resistor. Its Johnson noise can therefore certainly be regarded as insignificant.
That resistor should also have a cancellation effect on the bias current which should in theory reduce THD, and it will limit the current that flows into the amp input thus providing some protection during start-up and shut-off.
100 Ohm is in most cases smaller than even the tolerance of the feedback resistor. Its Johnson noise can therefore certainly be regarded as insignificant.
That resistor should also have a cancellation effect on the bias current which should in theory reduce THD, and it will limit the current that flows into the amp input thus providing some protection during start-up and shut-off.
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