Hi, I have been reading about feeding 128/256/512 DSD to a board that converts it to I2S (Amanero or JLSounds board) then take the I2S left and right channels and feed through a DC Block then through a LPF which removes the HF carrier/noise. This removes the need for a dac and the opamps.
The following are a couple of other forum threads...
No-Dac and No-USB
best dac no dac
It seems that it can be a simple (reasonably simple) implementation and the results appear to be very good!
Anyone have any thoughts about this approach/implementation?
The title suggests you are getting rid of the DAC, but you are just moving the DAC further up the chain.
Whatever the logic chip is that drives I2S output - this is now your DAC. A 1 bit DAC - with all it's advantages and disadvantages.
Advantages - less complexity, no digital filters, perceived more direct signal path.
Disadvantages - 1 bit audio has a huge amount of noise to filter. Even modern DAC's with a few bits have much less HF noise and so the analog stages have an easier job.
Jitter and isolation also have to be addressed. Then there is the OP drive. The I2S OP logic gate is your driver and has certain limitations.
So it's an easy intuitive solution just to low pass a DSD stream and get pretty good sound but to do it really well is a whole other kettle of fish.
How to do it really well? The whole circuit gets more complex, has some additional 'digital' filtering, jitter reduction and a few other things but it
then moves beyond a simplistic DIY project.
cheers
T