Solid State to replace Audio Research REF110?

I suspect the Pass Labs XA30.5 Would be a good match with the 90 db sensitive Proac Speaker. It's 4 ohm nomlnal load shouldn't be a problem for this highly regarded SS amplifier. I don't believe that the Proac is considered to be a hard/difficult load and in fact many drive them successfully with tube amplifiers.
Charles,

I believe Salectric's point is very valid. Many tube amplifiers are available
that when a tube fails it blows a fuse and that's it. This is much simpler and
less expensive than having to replace a resistor (s) or in some cases a
circuit board. I don't understand how using a resistor rather than a fuse
offers any sonic advantage. Replacing the fuse is so much easier and
requires no soldering or trip/shipping to a technician.
Charles,

I'm with Swampwalker on this issue. There are definitely tube amplifiers
that sound excellent and will blow a simple cheap fuse rather than take out
a resistor. I don't buy the ARC sound quality argument either. ARC is good
but there's better (matter of taste). A good friend had ARC for several years
and replaced it with VAC components which will blow a fuse instead of a
resistor. Nice as the ARC (no knock) was we both felt that the VAC was
clearly a step up in sound quality. ARC may have their own reasons but the
"better performance" doesn't hold up. Replacing resistors is an
unnecessary inconvenience compared to replacing a simple fuse.
Charles,

As has been pointed out, fuse protection isn't synonymous with sound degradation (this is a faulty premise). There are excellent sounding tube amplifiers that use fuse protection and don't destroy resistors in the process.

Knghifi,
You missed the point entirely it seems. ARC and CAT aren't the only ones
who have experienced and talented designers/engineers, in my example I
referenced earlier, my friend went from ARC to VAC. He strongly preferred
the VAC and I agreed with him, simply a matter of taste, I also have owned
ARC and it's a good product but IMO there's better available and I voted
with my wallet and moved on.

I have nothing at all against ARC components and they have certainly
withstood the test of time (as have VAC and other quality products).I dont
believe that ARC amps are unreliable, but their resistor replacement is in my
view a needless hassle.
My point in this interesting thread is I don't think that 'fuses degrade sound
quality across the board' is correct (some designs may and others don't,
it's implementation). My evidence is hearing very good tube
amplifiers(VAC is just one example) that IMO equal or better the ARC
sound. If you disagree that's fine and understandable, just a different point
of view.
Charles,

Dbarger,
Hey man , yes relax! We'll all just offering opinions which are bound to
differ. We all can agree there's more than one approach to handling a blown
tube and its outcome. This is fun and also educational from my
perspective. Obviously ARC has their reasons as do those brands that
choose an alternative method. I'm just trying to learn something here. My
ARC-VAC comparison was simply to illustrate two highly respected brands
that do it differently, that's all.
Charles

Hi Bifwynne,
Thanks and a very happy New Year to you and everyone as well.
Charles,

Hi knghifi,
Yes, my point as well . We don't disagree. I was actually hoping a designer/builder would come along and explain the rationale for either circuit protection option for handling a blown output tube.
Charles,