Join Date: Aug 2012
Location: New York
Originally Posted by cowana
I'm designing a preamp with a range of inputs, and have decided I want to add digital capability to it.
This will obviously comprise of the following three parts. I wish to keep everything working in hardware mode, so with no I2C/SPI control required.
The preamp will have three digital sources:
- Coaxial SPDIF
- Optical SPDIF
The USB obviously needs a decoder. I am currently looking at the PCM2707 as it seems to have positive reviews - but any advice is appreciated.
The receiver needs to switch between SPDIF sources and convert to I2S. I'm looking at the WM8805 for this (in hardware mode). Am I right in thinking that this requires an accurate 12.00MHz clock to run well?
*Edit: looking further into it, I'm not sure that the WM8805 can change between sources in hardware mode (which is very poorly documented). The CS8416 is MUCH better documented and has a more capable hardware mode - would there be much of a performance downgrade to using this?*
I've been looking at the WM8740 stereo DAC - this seems to have good reviews. However I don't need the differential output - the datasheet shows multistage external active filters and a lot of complexity. I'm trying to make a very compact design - the CS4344 DAC is a very compact solution requiring minimal external components. I don't mind a small performance decrease in return for simplicity and a design which is more likely to work first time - so I'll probably end up using the CS4344.
Any thoughts or opinions are valued!
22.1184MHZ for 44.1KHZ, and 24.576KHZ for 48KHZ or 96KHZ , 192KHZ.
In fact, we don't need preamp for DAC now, 100 ohm out put is better