Dear reader... The ProLogue Eight CD player review, while very positive, had some glitches. So as good as the review is (the more technically adept you are the more you will know why) to some folks it may seem "good" but not "great." So what happened? Before a review goes to print, we get a copy 10 days in advance to notify Stereophile of technical or factual errors, correct them, and to write a "Manufacturers Response." Stereophile is very professional about this, and they want to protect their excellent reputation in the industry for credibility. But this has been a busy year for everyone so we did not get the advance copy, and in fact we did not know about the review until it had gone to print. As luck would have it, there were two glitches. First, when John Atkinson introduced it into his system, he used a Parasound preamp with an input impedance of 27k ohms. This is not a good combo for this or most any tube CD player resulting in rubbery bass, but one that is almost impossible to come across a preamp that low. So go to your preamp or integrated amp, and look at input impedence. I found nothing lower than the traditional 50 to 100k ohms. That's perfect. Read furthur in John's review, and he changed preamps....and with that his opinion went in a way positive direction. I will take the fault for not asking what he was hooking it up to... so be it. Second, the ProLogue Eight is the only player I know of that lets you change the entire sound spectrum in two ways. First is tube changes: Fun, easy, go for it. Second, and most important, the the ability to make the player "faster." Read http://www.primaluna-usa.com/superivboard.htm The Super I/V Board incorporates a new type of op-amp that to our knowledge, has never been used by any audio manufacturer before. For $150, you are going to get: Slew-rate upgrade from 13 to 100V/uS 50% noise reduction Bandwidth upgrade of a factor 10! Or use Super I/V Board Plus for $235 which also upgrades the bypass caps and power supply caps, so with the increase of speed, detail, and quietness you get above, you get a prettier "picture" The agreement was that the player would be reviewed with both these options, but they ran out of time, and did not want to delay the review. If I was notified, I would have asked for delays for another month or two, because it is important.  A customer with a pair of Thiels or Focals may prefer the gentleness of the stock player. What if you changed your speakers to Martin Logans or Vandersteens? The I/V Boards are the answer! And what other player gives you that? So read about this impedance subject, we hope for a follow up with the I/V Boards in Stereophile and frankly....I can't remember them making much in the way of mistakes over all these years, and I thank them. Read all the reviews. No other CD player on the market does what this one does Sincerely, Kevin Deal PrimaLuna USA Click here to read the entire review