BPA200 with 2 lm4780

[mynameis_nobody]

Hello
Planning to build a BPA200 with two lm 4780. I am locking for Schematic for this. There is ofcourse schematic in the BPA200 documentation. But i would i would like to get one that some one has made.? i have search the forum and found some but they are not complete schematics? maby i have missed some then i would like very much like to se ..

So if you got a tested schematic please PM me or email me
my_name_is_nobody@telia.com

[AndrewT]

BPA200 from the 4 chipamps inside the dual 4780 is asking a lot driving an 8ohm speaker.

There are only two To220 (wide) thermal interfaces to dissipate all the chipamp heat.
This is likely to result in thermal problems.

[mynameis_nobody]

So the best alternativ is to go with a original BPA 200? with lM3886?

[pacificblue]

Originally Posted by mynameis_nobody

So the best alternativ is to go with a original BPA 200? with lM3886?

Not the best alternative, but less likely to switch off due to overtemperature.

[Lo_Tse]

Originally Posted by pacificblue

Not the best alternative, but less likely to switch off due to overtemperature.

Just curious, what would be the "best approach" (if there is one) in your opinion?

Lo_tse

[mynameis_nobody]

Originally Posted by Lo_Tse

Just curious, what would be the "best approach" (if there is one) in your opinion?

Lo_tse

Yes same question here i have seen it been done before?

[AndrewT]

lme498xx + transistors to meet the duty you require.

National won't like this suggestion, cos they make profit on one chip rather than the 4 sets of profit from selling 4 chips to the misguided builders.

[mynameis_nobody]

Originally Posted by AndrewT

lme498xx + transistors to meet the duty you require.

National won't like this suggestion, cos they make profit on one chip rather than the 4 sets of profit from selling 4 chips to the misguided builders.

Got any schematic andrew?

[AndrewT]

google National lme49810, 49811, 49830 datasheets
Or simply search this Forum

[pacificblue]

Originally Posted by Lo_Tse

Just curious, what would be the "best approach" (if there is one) in your opinion?

Lo_tse

For several hundred Watts of output power class D is the most reasonable thing. Chip amps are good for 50-60 W per channel. Solid state and hybrid ICs for the power range in between. Driver ICs like the LME498xx reduce the complexity of solid state amps, if not the cost.

Several chips in BTL or parallel can make sense in an active speaker when you need different power levels for different drivers or the same power level for drivers with different impedances and from the same rail voltage.

Building BTL, PAR and BPA as full-range amps makes for a nice pastime, but they don't offer any significant advantages over other amps. They are as expensive or even more so. And they are also nearly as complex. The schematics may appear straightforward. Routing power, speaker and line signals past each other without interference is not. Neither is grounding. So you either make compromises that result in an inferior amp or you put so much brainpower into it that you might as well build a solid state or class D amp.