Tube rolling on Leven CS 600


Good Morning.
I have a Leben CS 600 amplifier driving Devore O93 speakers.  I am using Luna Mauve ICs with a Linn Akurate DS steamer, Feikert Volare TT, and Cal Audio Icon Mark ii CD/Heed Abacus DAC. The Leben came with 6L6GC tubes, but can also run with EL34 tubes.
Overall it sounds great but on some older recordings ( mainly CD or streaming) its a tad bright/forward; in part due to the poor acoustics of my room.
I wonder if some tube rolling might be worth a try.
Has anyone any experience/thoughts?
Thanks

mpomerantz
I would look to the signal valves, if it's a tad bright. 6L6 are not really known for being bright. The 6CS7 signal valves, are not a cheap valve either. I would look to GE, RCAs and stay away from Sylvanias, they can be brighter than most (they have there place though). 

If you go to EL34s, you might lose some of the MB/Bass.  They will bring out the mids so the bottom might sound a bit thinner..

Room treatment? Wall and ceiling panels would be a nugget for sure.. 

Regards
Your digital sources might be a tad "bright" depending upon the recording. Changing tubes is often a futile pursuit!
For an EL34 alternative try the Gold Lion KT77's a great sounding EL34 variant. Also NOS 6L6 tubes are pretty affordable and might warm things up over current iterations. Also oldhvymec is right the small signal tubes have a large impact on the sound. That's a great little integrated have fun tube rolling!
a great 6L6 family tube is the Tung Sol 7581A....my experience with the Gold Lion KT77 is terrific tone, detail and soundstaging but deficient in the mid and upper bass. The 7581A has stellar bass while being a very transparent bottle.