i have changed the tubes in my musical fidelity x-can v3 with very good results i now have russian millitary spec tubes,, so try you may be suprised also run the valves in for three days before judging the change..
My new Valvo tubes arrive tomorrow for my fatman as well as a russ andrews powermax cable - so hopefully will be enjoying an increse in detail and better bass very soon.
very surprised that no one else on here seems to have tried the tube swap on this - can't resist the need to tinker with stuff
well just as an update ended up having to use a merlin tarrantula mains leads as the russ was too short my fault as didn't measure - also swapped out the tubes for the valvo and although i'm still running them in the sound has suddenly become far more open, detailed and the bass is tighter - great result.
valves are great i have found a real love for them - the carbon i don't think is good enough to be used as a main setup even though its great - they do make proper stereo valve amps but never tried one.
it adds space and warmth to the ipod which in my opinion is exactly what it needs - if you are unsure try buying a valve headphone amp and using that as an experiment - the little dot is great for playng with tubes so you can buy to roll and try new things - you can also use it as a pre amp with your power amp not tried this myself but read very good reports - i'm still getting used to it and a lot of enjoyment from it