I am designing a DAC for my house with a WM8804 to receive S/PDIF then I need to convert the I2S to an analog signal.
Does anybody here have experience with these 3 parts, what is the best part to use?
PCM1794A
ES9023
WM8741
Thanks;
Leo
Does anybody here have experience with these 3 parts, what is the best part to use?
PCM1794A
ES9023
WM8741
Thanks;
Leo
All of them are good. The ESS9023 seems to has easiest application but with still very good sound. PCM1794 will be the most demanding in applications, but you'll have lot of possibilites. I had never listen to WM8741 but datasheet looks promising and may fit bery nice with the reciever...
Find some sample application and then select the IC according to it..
Find some sample application and then select the IC according to it..
If the implementation does not looks too complicqted for you i would recommend 1794A. Really good sound.
OPA6132 looks rather similar to THS4131 whose datasheet shows an internal schematic. Not really recommended to expose an undegenerated very low noise LTP to all that RF straight out of the DAC.
Yes, they are essentially the same IC. I think TI just bins the lower performing parts as the OPA1632.
For using either with the 1794A, have a look at the Twisted Pear IVY schematic...
The IVY Balanced Line Stage
The opa1632 works really well as I/V in this situation (they were already used years ago by Bel Canto for that role). But...
* +/-12V is a bit too high, this chip runs very hot. You can keep it at +/-9V.
* you shouldn't ground VCOM. Doing that will keep the outputs at 0V but raises the inputs DC offset by the DAC current offset multiplied by the I/V resistors value. It's bad because the protection diodes internal to the dac start conducting, raising distortion. You need to feed a negative voltage reference (or a servo) to vcom to null the offset at the input. This will introduce offset at the output, but it will be nulled by the differential receiver.
edit: the other option being to null the DAC current offset with CCS.
* +/-12V is a bit too high, this chip runs very hot. You can keep it at +/-9V.
* you shouldn't ground VCOM. Doing that will keep the outputs at 0V but raises the inputs DC offset by the DAC current offset multiplied by the I/V resistors value. It's bad because the protection diodes internal to the dac start conducting, raising distortion. You need to feed a negative voltage reference (or a servo) to vcom to null the offset at the input. This will introduce offset at the output, but it will be nulled by the differential receiver.
edit: the other option being to null the DAC current offset with CCS.
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