The best advice I can give you is to get yourself a CD transport and listen to the CDs directly. You will be amazed at how much better it sounds compared to streaming.
JC
I wish people who claim this would be more specific, because I'm simultaneously curious and skeptical.
Which transport and which streamer? Or do all transports sound better than all streamers? Which digital output was used (both coax, both TOSLINK or a mix, same cables or a mix)? Into what DAC? Which streaming service was used, with what quality settings (and volume normalization, etc.)? Which CDs and which tracks? Was it definitely the same master or is there actually no difference for some tracks? Is the streamer connected via WiFi or Ethernet? Does it matter whether you're actually streaming from the internet vs. a local device over the network vs. some storage directly attached to the streamer, e.g. a USB stick?
Is anyone who is claiming this by chance using the streamer's DAC and the CD player's DAC (obviously not you since you said transport)?
I have a Bluesound Node 2i and the Schiit Yggdrasil and various other DACs. Should my Samsung Blu Ray player (BD-H5900) with coax out sound better already? Or what's a transport that someone found definitely superior to the Node 2i?
Obviously using my USB Blu Ray drive with a laptop is not advised, right? Heh, maybe that would even work with the Node 2i.
In my case, the Node 2i is connected to a TOSLINK switch, which is connected to a MUTEC MC-3+ USB reclocker, which feeds the Yggdrasil via BNC. Starting with the MUTEC, everything is powered by an Audioquest Niagara 1200, while the switch and streamer are powered by a Furman PST-8D. Given this amount of treatment and electrical isolation, would you still expect any CD transport to sound much better?
I'll probably try Schiit's transport when it comes out, since I am curious, but I'm certainly hoping the difference is negligible because streamers are substantially more convenient and don't make mechanical noises like a spinning disk drive.