Ok the Bluesound is a decent digital transport as long as you use an external DAC. I recommend an “analog” sounding Lampizator Baltic 3 for that. You should also look into the Auralic Ares G1 or G2.1 streamer.
Those old transparent cables are sucking the life out of the system a bit. Try Shunyata delta or alpha level power cables (do not get the noise reduction connectors for the tube gear get the XC not NR…NR is for solid state and does weird things with tube gear I tried them with) and then for something accurate for speaker and interconnects an American company called Kubala Sosna you will find has more resolution but won’t emphasize treble or sound weird like other brands and I recommend Temptation level in the middle to start. That’s what I use in my YG Accoustics Carmel 2’s. Your B&W speaker has a more forward sound with the diamond tweeter and you need a cable that is accurate and won’t turn them into double treble murder canons. GTT Audio can help you with the cables and maybe upgrading the streamer to the next level with an Auralic Ares. Fred can help you over at Lampizator North America since they sell direct. Sources are all neglected it’s not just the amps. That old Linn is cool but a better turntable is a Kronos Sparta 1.0 that has a counter rotating plater underneath the main plater to counteract all vibration but turntable last.
Amps to look into are Belles Audio….Think Pass Labs and McIntosh with more resolution but better value. Audio Connection in NJ can help with them and they will go perfect with your new preamp. You just need a Belles virtuoso stereo amp.
If you can swing it try Mola Mola Kalugas they are class D and pair great with tubes and the treble is sweet and slightly rolled off to curtail the diamonds. I am 40 so I tried a lot of new tech most people refuse to try. The Mola Mola needs to be plugged in a whole day before they are ready to do critical listening.