Second hand Esoteric X-1 and X-3 SACD players use the Burr Brown PCM1704 R to R ladder Dac and sell between 6 and 8K. I own the Esoteric UX-3 which is the same as the X-3 except it also does DVD audio. It uses the same DAC and I will never sell it. It's that good.
Why go through all of the trouble modding an out of date and unsupported disk player that doesn’t sound that great to begin with? I don’t get the Oppo attraction and the prices of 105’s/203/205’s are crazy these days.
Just like the idea of using the holo May or Denafrips DAC so I can use digital files plus use a SACD transport to send to the DAC. I didn't know that the HDMI I2S was becoming a standard or at least something that multiple different brands were using. Not an Oppo fanboy but not sure who else is doing the HDMI I2S PS Audio format?
I’ve heard/read comments from others praising the I2S interface but it still seems to be the Wild West as it’s not a standardized interface. Some builders use it to interface between components within their product line but brand to brand interface leaves you hunting for component pin outs, custom cables and being at the mercy of how much effort the designers put into its integration. Bottom line- there are many excellent DAC’s and players that don’t require I2S to sound their best.