output resistor matching for LM4780 paralleled

[Audiophilenoob]

I really did search on this.... and couldn't find my answer

for paralleling a pair of LM4780 where should the output resistor be placed for matching?

also is there any set resistance for these chips for paralleling them? I know they need to be 0.1% tolerance but is there any specific ohm? What about watt capabilities (1/16 watt, 1/8watt, etc)

I'm refering to the supposed extra resistors needed in the outputs for paralleling...
not the resistors that are already in the schematic
thanks

 

[bigmike216]

0.1-0.3 ohm should work fine, 3-5 watts. they don't need to be 0.1% tolerance though...

 

[Audiophilenoob]

0.1-0.3 ohm should work fine, 3-5 watts. they don't need to be 0.1% tolerance though...

1% tolerance is ok?

also these are placed in line with the output to the speaker terminals? or elsewhere?

 

[bigmike216]

They are placed after the output pins of each chip.then the other end of the resistors are connected together in parallel for your parallel amp. 🙂

 

[Audiophilenoob]

They are placed after the output pins of each chip.then the other end of the resistors are connected together in parallel for your parallel amp. 🙂

many thanks 🙂

 

[tlmadsen]

It is more important that you match the gain of each amolifier and take care of DC-offset (if you have such). A "bigger" output-resitor will to soem extent take care of the last issue

Have fun

Thomas

 

[Audiophilenoob]

can these resistors be non-inductive/wirewound??? 😕

 

[motherone]

Yep. Those are pretty much your best bet. Mouser has a nice selection of the Dale non-inductive wirewounds.. Check the LVR3 series.

 

[Upupa Epops]

Look at www.czechaudio.com - at my PA 03, some photos are there 😉 .