Pros - Airy and detailed, good bass, addictive midrange, tube-rolling, discrete components, moddable, price
Cons - Discontinued
Buying a used MF X-Can V3 is one of the best deals I have ever done. This is high quality stuff easily compared to headphone amps costing three or four times the price I paid. The amplifier is using exclusively discrete components. It works very nice driving my Sennheiser HD650 and even AKG k701 and k501. The rated power output is 1 W so I guess this amp would even manage to drive a pair of sensitive speakers. The amp I own is modded with some new Panasonic capacitors and a pair of Russian NOS tubes. I cannot speak of any differences in SQ between the modded vs unmodded X-Can but only the fact that anyone with modest soldering skills can change some vital components in this piece of equipment is a big pro to me. The moddability of this amplifier makes it a great second-hand value. Highly recommended!
Pros - Quiet, Inexpensive, Musical Fidelity Quality, Solid Enclosure but Easy to Tube Roll
Cons - No Longer Available New
I'm going to start by disagreeing with the two previous reviews.
You DO NOT need to tube roll this amp. The original Jan Philips 6922 are considered a premium version of the 6DJ8. With the Sennheiser HD-600/HD-650s, you get what I'd call a more mild tube sound. It's detailed enough to hear the page turns and periodic shuffling during some symphonic/chamber performance. It's smooth, but not excessively, and has the punch you'd get with an SS amp. Of course, you're probably buying this used at this point, so you may want to swap warn tubes for that reason alone; but there's no need to go nuts and buy break-your-budget NOS replacements -- feel free to just replace with the stock JP 6922s.
That said, I purchased a set of Amperex 7308s as recommended by the first reviewer. And boy do they sound amazing! Extremely smooth and detailed. They cost in the high $100s, so they are near the value of the amp. But boy!
In terms of comparison to modern amps, I don't have anything to refer to. But the quality of the V3 is absolutely supreme, and you really aren't going to go wrong by any means in terms of "bang for buck." Especially in the current used market. You also get a solid case that completely encloses the internals including the tubes, so you don't have to worry about little ones accidentally touching them.
I love the company name "Musical Fidelity," because that really describes what you hear with this amp.
Cons - Needs the out-board power supply/ upgraded tubes
I knew the quality of the MF gear for the money and had heard the X-can V-3 yrs ago, I just wasn't into headphones back a few years. So in 2009 I bought a perfect used X-can V3 off of Audiogon and was somewhat pleased with the sound that it produced with my Sen.-HD650s....right out of the box, but knew that the stock (crap)6922 tubes had to go. I installed a NOS pr of my Amperex 7308 SQ grade tubes and was smiling with the improved sound right away.. These tubes make the V3 so much more detailed and really is the 1st step in any upgrades that "one" should do if they purchase a MF Xcan V3 or V8 for that matter...Next I found a "Demo" X-PSU V8 power supply, what a find... And that took the V3 to a whole new performance level.....A must if you can find a power supply on sale, I don't think I'd give full retail for one, just keep looking for demos or used....... All in all for a store bought headphone amp I don't think you can go wrong for the performance you receive .....JMO...PS Yeah, I know about the sound you get with changing Caps, that will be a winter project.......