Plinius SA250 Mk.4 vs. Pass Labs X350

I like Plinius, but look at it this way. The Pass is unquestionably one of the best amps out there in it's price range and holds it's value as well if not better than most of it's competition. You cannot go wrong with the Pass no matter how you slice it.
Consider this.......
Go immediately to an Electrocompaniet dealer and listen to an AW250R amp. While you're at it, check out the AW180 mono blocks. Since you like the sound of pure class A amplification, I must tell you that I would not be surprised if you posted back later that you took my advice and became the ecstatic owner of one of those amps I suggested. Hell, if you can afford an X350- consider the Nemos. My FAVORITE amp regardless of cost or manufacturer.
Good luck!

I have owned Plinius (SA-100 Mk III) and currently own Pass (Aleph 4). I have heard the X-350, but not the SA-250 Mk IV. I would say that Pass unquestionably makes the better amp on the basis of detail, soundstage, neutrality, high frequency and low frequency extension. This was clearly evident, but the Plinius had such marvelous synergy with the other pieces in my system, it makes this comparison a much tougher one than it should otherwise be. The Plinius has that iron-fisted bass (although it is not that deep) , great dynamics, and a marvelously clean midrange, upper midrange and high end. I don't see how anyone else other than you can weigh the pluses and minuses, ideally comparing these two amps in your system.

Unfortunately, I live in the Sierra Nevada Mountains near Yosemite Park. The closest high end audio stores are three hours away and they don't carry either Plinius or Pass Labs. To go to the greater Los Angeles area to hear these units would be over 8 hours away and LA is always a nightmare to travel in. So I'm hoping so of the audiophiles here can be helpful in my making a decision.

Have been in this hobby since 1957,and have owned countless gear.Had tubes when that was all there was.Have owned many Nelson Pass products from Threshold,and I have heard the X350.If you can afford the X350 -- BUY IT --.But b forwarned the Pass X350 is intolerant of weakness in the component chain and will expose those weakness's.I own Threshold Class A amps. They are rock solid in every respect.I have tried other preamps with the Threshold amps but always come back to the Threshold PreAmps,as the match to Threshold to Threshold is clearly superior.I would dare say the same could hold true for the current Pass Labs product. The X350 I listen to was using a Pass Labs preamp. If and when the Threshold gear gives up the ghost will be going to Pass Labs.Lets face it Nelson Pass had the ground breaking white paper on Cascode design in the late 70s and was awarded a patent for that design. He has been further refining that orginal design.Make no mistake Nelson Pass designs and products are timeless.I have wasted far too much time and money trying to find better product.

What about the SA250MkIII with siltech silver wire upgrade vs. an SA250MkIV? The MkIII can be had at bargain prices these days. Is the sonic difference between the two worth the difference? I know this is slightly off topic but I think those reading this thread would be interested in this issue.