Response to Chris:
Actually, I didn't expect the X-10D to improve the sound of the (Theta) Cobalt 307 DAC--I just tried it there to see if I could get some use out of it. I had originally tried it directly on the output of my Sony carousel, but it didn't help enough--God knows that's a tough assignment--hence the DAC. But it did improve the system overall in the preamp's EPL loop. Until I upgraded the speakers and wiring, which prompted my Musical Chairs approach to its placement.
I have since tried it on the output of my CD-67SE upstairs, and even though the 67 was originally working into a tube input stage of a C-J PV-2AR preamp, it seems to have taken the edge off the unit, without a dramatic loss of detail. It's effect on the bass, however, is fairly strong, but fortunately the Acoustron LWE-1A 15" 3-way motional feedback speakers on that system allow me to taper off the bass in 3 dB steps--it required a 6 dB rolloff to stay relatively smooth and not over-emphasized. People should know that the X-10D seems to add 1.5 to 2 dB of gain, which with a 2 volt output from a typical CD player at full volume, may be a marginally high signal level for older equipment, which somewhat negates it's value in upgrading older gear.

I like it upstairs--I'm keeping it. It lets me run my Dyna Mark III's in Ultralinear mode, where before I could only stand the CD player through them when they were running as Triodes, which cost me 3 dB in output per channel. So Chris, while you are entirely correct as to its intended purpose, it truly is a "try it before you buy it" type of product. Fortunately, not only does Audio Advisor have a great return policy, but a lot of people have apparently tried it and not bought it, so it's available in significant demo quantities.

Just thought I'd clear up any misconceptions from my last post. Sorry for the running thread.

BTW, I got a great deal on my PSB Stratus Gold i's from Steve at Country Video (610-828-2600). Wouldn't think of any other speaker from any other dealer at the price.

73, Roger

P.S. Given it's newfound utility, I'm increasing my rating from 2 to 4 stars. Gives me a lot of credibility, I know.

The X10D is designed to take the load off the cheap op-amps found in low end CD players and it does just that. It also adds a slightly tubey sound (warm, liquid, and fatter bass). Roger - why do you expect to hear improvement when placing it after a Theta DAC? Overall, excellent product!

Slight correction on my last post:
I only rolled off the bass at the speakers 2 dB, not 6 dB as I reported. The LWE Acoustron speakers (15" acoustic suspension 3-ways, circa 1969) have three level controls on them--variable mid- and high-frequency, and a 6-position switched bass control. (I remembered this when I was in bed last night.) The mid- and high-frequency level controls adjust DOWN from flat, and because they are motional feedback speakers and connect back to the feedback loop in the Dyna Mark III's, the bass level control adjusts in six 1 dB steps UP from flat (it reduces feedback at low frequencies, thereby increasing output level). I had the bass control at +2 BEFORE the X-10D went in after the Marantz CD-67SE, and I had to run it down to flat AFTER. This agrees with measurements I made down in the studio that showed that the X-10D adds between 1.5 and 2.0 dB to the signal path.

Trying to be accurate, here.

How about those Legacy Focus reviews, eh? Jeez.

Still hovering at 4 stars.

This product does not produce great results. When plugged in, I had to ask myself "did I really hear anything." Then I unplugged the device. This is something I can live without. It does very little and it removed detail from my system. Bass will be more strong, but sometimes it sounds very flabby and uncontrolled. I dont understand how this can be considered a great product. It seems like it's just an expensive loudness button, with tubes.

Review Redux, or Part Two of a Many Splendored Thing:
I reviewed this little tube buffer a few months ago, as you can see down below--why does everyone say above?--and at the time, it helped what I was using. Lots has changed since then. Were it not for the fact the the site lost my review of the Carver HTR-885.1, I might have reported it sooner, but now's the time.

I finally gave up on the JBL 4312 Control Monitors I have in my studio's mid-field playback system, and grabbed a pair of Stratus Gold i's, put in biwiring with a couple pair of AudioQuest Type-4's, modified my Hafler DH 500 so it wouldn't trip on the newfound bass--must have been modulating something--and have never been happier. All of a sudden I noticed that source material sounded better without the X-10D--it was in the EPL circuit of my AGI 511A preamp and I could do A-B tests very easily. Notably, Bonnie Raitt's "Nick of Time" CD sounded definitely more congested with it. So I pulled it out of the EPL loop and stuck it on the output of my Theta Cobalt DAC. Worse--boomy, flabby bass, with a noticeable lack of detail in the high frequencies. My source is an admittedly marginal Sony carousel, Toslinked to the Cobalt, but valuable as a test source for it's (formerly--pre-DAC) screechy tendencies.

So now I'm at the point where the X-10D produces no beneficial effects anywhere in the chain. The only place I haven't tried it recently is the spot I originally bought it for--between the preamp and the amp, but it produced almost no effect when I initially tried it there on the old (JBL) speakers. God, I hate JBL's--bassless, highly mid-range oriented, and annoying.

So, now I think I'll drag it upstairs and stick it on the output of a Marantz CD-67SE and see what happens. It should be interesting--the SE is feeding the AUX input of a C-J PV2AR preamp, into a pair of modified Dyna Mark III's, so I don't expect much improvement, but it's worth a try. If that fails, I'll try it somewhere else, say on the output of the Musical Fidelity E-60 feeding an E-10 in this room, but they are a beautiful pair, and I don't expect much help there, either. After that, it's up on rec.audio.marketplace for sure.

The bottom line is--if this thing helps your system, it needs work.

Be an organ and tissue donor and inform your family of your decision. A little PSA from a PSB owner, as I like to say.

73, Roger WA3FLE

P.S.--Oh, mark this item down from 5 stars to 2 stars, please. Thank you.

I have bought this device mainly to improve the gutless sound of my Sony DTC-690 DAT recorder. It definitely did the magic! It's not so much that I get more highs or lows or whatever. I just get more music! The music just sounds more relaxed, involving and shiny. It makes it much more easy to follow one particular instrument in a band or orchestra.
These things are not immediately noticeable. You have to listen to it a little longer. In fact, the less you "listen" to it, the better you hear the results. It just makes the music more interesting to listen to and will destract you more when you are doing something else than listening.

I tried it with my Marantz CD72 CD player however, and did not detect a noticeable difference. The unit is thus very system-dependent. DONT'T buy it without having tested it! It tends to work best with equipment that has a high output impedance, as my Sony has.

I have given this unit 4 stars because of the system dependency.

Just my opinion...

Before I use it with my Sony DVP-S7000 (with either Analog or Digital Output) and Yamaha RX-V2092 , the sound is too bright and will fatigue my ear. Now, this problem disappears after plugging in the X-10D between the DVD and the Receiver.
The sound is more warm, more forward and more like music. If you are looking to upgrade a mid-end CD player like Sony, try this. It costs much cheaper than a decent cable but you'll get more from this magic cone.

Burned in the x-10d for about 5 days to see if I can hear any improvementswith my Marantz 65se. It seems to improved the dynamics of the Marantz (or
did it?) The mids are little warmer and more prominent,but my treble is
still slightly forward ( no change ). The bass is slightly more extended,
but I didn't get the great improvements that the other reviewers had
with their cd player. So is it the X-10d or is it the extra pair of
interconnects that is improving the sound of their setup? For me, I
should have spent the money towards a new amp, before wasting my time
tweaking.

This is truely a remarkable product. If you own any budget priced source components (CD players, VCR's DVD players, etc) this one is for you. Basically what it does is provide a high impedance load for the source component. This means that the component won't have to pass as much current, and therefore won't tax it's output amplification stage as hard as it would driving a preamp.
I own a Marantz CC-67, and this thing has worked magic for it. The soundstage is deeper and wider than ever before. The bass (previously lacking) is deep and powerful, and the dynamics: Wow! Before the addition of the X10 this player had little dynamic contrast, and now it has it in spades.

For $200 this thing is really a steal. I'll put my little Marantz with the X10-D up against players costing 2X and even 3X as much as it. If you have a budget priced component and you're looking to upgrade, look no farther. If you own higher priced components (>$1000) or seperate transport/DAC's, this probably isn't worth your time, as the output amps for these are superrior to budget components.

I bought one of these things hoping that it would somehow make my Sony CDP-997, purchased 5 years ago, sound richer. As it stands now without any aid it sounds thin...The rest of my system are AudioLab 8000S Int Amp, Monitor Audio PMC703 speakers, Goertz MI2 and MI1 bi-wired, Sony Tape Deck and MiniDisc Player (StraightWire Chorus interconnects throughout the system). The combination of AudioLab, Monitor Audio, and Goertz makes my sytems extremely revealing. The Sony MiniDisc Player sounds more solid because it has a larger R-Core transformer as an output stage? Anyway, the X10-D made a marginal improvement, or can I really call it an improvement? Yes it does make it sound a bit more tube like with a fuzzy - frizzy relaxed nature. Trumpets and violins have more timbre and realism but it also makes the vocals sound even thinner (I think it has something to do with the way it widens the sound stage like many DSPs do by tricking the ear into hearing something that's not there). Suddenly the performer is 2 feet behind the band instead of in front. The bass is more pronounced but also more muddy. It did absolutely nothing for the highs...my cheapo CD player ($350) still sounds too bright. I think I will return it tomorrow....
P.S. I saw that there is another tube line conditioner made by Z-Man called the ASE which looks promising. I ordered one last week and should be arriving shortly. I will post the results of my findings later.