My LM4780+DRV134UA True brige balance AMP

[IceMing]

Following project is my LM4780+DRV134UA True brige balance AMP.

I use DRV134UA to make BTL signal, and LM4780 ampfile it.

[weissi]

why not simply take the balanced signal direct from the source, i.e. a symetric DAC

[Ponz]

the chip drv134 made from TI is a great chip for converting unbalanced signal to balanced signal. But it has a problem about output DC offset.
the DC offset problem can be solved by connect coupling capacitor between output and sense pin, but still has about 1~10mV offset voltage.

the other choice is replacing drv134 to THAT1646.
THAT1646 chip is made from That Corp and pin compatible to drv134
but has better performance and sound quality.
the info. for 1646 is available on:
http://www.thatcorp.com/1600desc.html

[IceMing]

Originally posted by Ponz
the chip drv134 made from TI is a great chip for converting unbalanced signal to balanced signal. But it has a problem about output DC offset.
the DC offset problem can be solved by connect coupling capacitor between output and sense pin, but still has about 1~10mV offset voltage.

the other choice is replacing drv134 to THAT1646.
THAT1646 chip is made from That Corp and pin compatible to drv134
but has better performance and sound quality.
the info. for 1646 is available on:
http://www.thatcorp.com/1600desc.html

thank you for advise, I will try it.

I use coupling capacitor to block DC offset, but not perfect.
If I build a servo circuit for it ,is it much better?

I don't know how to put my picture to this bbs.
The following link is my project.(langue is Chinese Simplefy)
http://bbs.hifidiy.net/viewthread.ph...&extra=&page=1
and
http://bbs.hifidiy.net/viewthread.ph...&extra=&page=1

[Ponz]

i can't see schematic in the url you posted.
do you have the link of the schematic?

[YFW]

Originally posted by weissi
why not simply take the balanced signal direct from the source, i.e. a symetric DAC

Yes,there are a lot of DAC have original balanced output,for example,CS4390/AKM4395.