Sounds like a decent Dac/Streamer combo to replace the NAD may be a good idea.
Yeah, I’d wholeheartedly agree with that. Here’s a great streamer you can also load your CDs into…
https://www.usaudiomart.com/details/650011170-innuos-zen-mk3-1tb/
And you can add this excellent Denafrips R2R DAC…
https://www.usaudiomart.com/details/650012161-denafrips-pontus-ii/
And with your budget you could even add this Denafrips Iris DDC that’ll let you take advantage of the DAC’s superior i2S input…
https://www.usaudiomart.com/details/649988598-denafrips-iris-ddc/
Using this simple HDMI cable, which is what I use from my Iris into my DAC (and yes, get the 0.5 foot length as the shorter the better for i2S)…
https://www.monoprice.com/product?p_id=13578
This would be one kick-butt streaming system on the relative cheap. Hope this at least gives you some food for thought, and best of luck