Anybody know about "tube buffers".

I was wondering if anyone has used the Musical Fidelity tube buffers that supposedly upgrade your CD to tube sound. Are they effective?
Well.....I'll tell you what I've found. I tried the X10-D on the fixed outs of an Adcom GCD575 with no improvement. Tried it on the fixed outs of a JVC CD 100 disc changer with "a little improvement". Then I added a Adcom GDA600 to my GCD575, big improvement with the D/A converter. I have a Classe' 30 preamp and a pair of CA100's with low budgit cables (I'm auditioning now) I heard that Classe' amps sounded great with tube pre's like Audio Research ( but I can't swing that right now). So I stuck the X10-D between my pre and powr amp. MASSIVE improvement!!! The bass really tighten up and became firmer! The music sounded warmer. This leads me to believe that the X10-D would work best if you place it on a players variable out to drive an amp directly or between the pre and power amp to get a "tubed" sound.
i have a z-man ase w/nos mullard tube. my (s'phile class-c) nad cd player is not suitable for serious listening w/o it.
Skip the tube buffer thing...been there, done that...put an MSB Link DAC in its place and the tube buffer only got in its way. Get yourself a sweet MSB Link DAC III if you're on a budget, and it should really have you smiling. A Perpetual Technologies for $699 if you can afford it. We are authorized dealers for both. Jeff