Generally speaking, bluray discs will have better audio and video than streaming because streaming is usually somewhat compressed video and is limited to Dolby Digital audio. Bluray has better video resolution on the disc and also provides hi-res bluray audio formats (DTS-HD MA and Dolby TrueHD).
That being said, I think you may be able to get better audio/video from a Roku streamer if you use a linear power supply on the Roku. This is because pretty much 99.9% of bluray players out there will actually have a switching power supply. Some may have linear power supply for analog audio output (i.e. oppo 105/205), however they still use switching power supply for digital/HDMI.
Here's an old thread that I wrote up:
https://forum.audiogon.com/discussions/musings-on-switching-power-supplies-lps-for-oppo-directv-radi...
If you get a Oppo or Panasonic bluray player and then upgrade it to linear power supply (i.e. Oppomod website or others), then it is likely to meet or beat a Roku with linear power.
A power conditioner may help a little bit on the streaming box, but you are still using a tiny switching power supply. A "Linear power supply + Roku" would be highly superior to "Power Conditioner + Roku".
In all my testing, R&D, modifications and experience, the power supply is the single most important factor in most audio electronics.
That being said, I think you may be able to get better audio/video from a Roku streamer if you use a linear power supply on the Roku. This is because pretty much 99.9% of bluray players out there will actually have a switching power supply. Some may have linear power supply for analog audio output (i.e. oppo 105/205), however they still use switching power supply for digital/HDMI.
Here's an old thread that I wrote up:
https://forum.audiogon.com/discussions/musings-on-switching-power-supplies-lps-for-oppo-directv-radi...
If you get a Oppo or Panasonic bluray player and then upgrade it to linear power supply (i.e. Oppomod website or others), then it is likely to meet or beat a Roku with linear power.
A power conditioner may help a little bit on the streaming box, but you are still using a tiny switching power supply. A "Linear power supply + Roku" would be highly superior to "Power Conditioner + Roku".
In all my testing, R&D, modifications and experience, the power supply is the single most important factor in most audio electronics.