Bryston 4B3 vs Mac MC462 vs Pass Labs X250.8, OR... GRYPHON Diablo 300?

Over the next few weeks I am organizing in-home demo of  three pre/power amps for my B&W 803D2's, and will purchase whichever sounds best.  I will be testing the following gear, which is based on what's available where live:
-Bryston B173 / 4B3-McIntosh C47 / MC462
-Pass Labs X250.8, if I can get my hands on one (will probably use the C47 pre-amp to test with this)
The Gryphon Diablo 300 is also a candidate.  I've seen some strong comments from others that Gryphon is in another league compared to the others.
My question is, barring what sounds best to me during my auditioning, in general to most people would the Diablo 300 really beat the others in my list?  And, are there any material disadvantages to sound quality considering the Diablo is an integrated vs the other choices?  I don't really care about having separates, but sound is obviously important.
Secondly related to the Gryphon, there is only one Gryphon dealer that is even remotely close to me.  Should that dealer cut ties down the road, or go out of business, does anyone know how I might go about getting service for the Diablo should I require it at some point?  Is that a valid concern?  There are multiple Mac dealers near me so that would not be so much of a concern.

Thanks in advance for any feedback....


Thank you for the review. I said it earlier, the Bryston cubed series and Mac MC462 (452) are two of the amps in my list of 6 I’ve narrowed it down to. Thus it’s like I have a personal reviewer, lol.

Sounds like that recommendation I got on the Brystons was dead on. Keenly interested if you still feel the same after hearing the mc462. 

I should be auditioning the 462 on Tuesday if all goes as planned.  However I’m only able to test in-store and not in my home so it won’t be a fair comparison to the 452.  To make matters worse I will be hearing the 462 with B&W 803 D3’s, which are I believe a fair bit better (and more expensive) than my D2’s.

The main reason I’m testing the 462 is as a reference point for what I’m now most interested in testing, which I will also test on Tuesday- the Gryphon Diablo 300.

I have notes on what I found to be lacking with the 452, and if the Diablo can beat the 462 in these areas and do nothing else wrong, I think I will have found a winner.  If not, then I’ll have to start searching for a suitable preamp for the Bryston.

I don’t mean to steer you away from McIntosh too much as I can see how some would prefer its smooth and complete midrange, but another thing I was a bit disappointed by was build quality.  Not that it was bad. But up close, it just didn’t come close to the rock solid feel the other brands in the same price range had, despite the heavy weight.  Mcintosh preamps I thought on particular did not give an impression of sturdiness at all.  This was a surprise; I didn’t expect to have that reaction.

Nevertheless I will post an update on the 462, but all I will have to directly compare it against is the Gryphon, which probably won’t be a fair fight.

Understood on the different setups. It doesn’t matter as much as I’m looking at the Bryston 14b3. So if the 4b3 was nearly or in some areas better than the 452, it can be guaranteed that the 14b3 will be the clear winner as it has been reviewed as far better than the 3b or 4b combined. I doubt 462 is that much better than its previous model.

I was disappointed to hear about the Mac. To me, it's the best looking of the bunch. However, the sound is the most important thing in the end. 
Morg111,  totally thinking the same as you.  If I do go Bryston I too will actually go 14B3 for greater transparency vs 4B3.  However when you factor cost of 14B3 and suitable preamp, I can get the Gryphon Diablo 300 for the same $$$.  And consensus seems to be that the Diablo is “in another league”.  Will see how I think  the Gryphon compares shortly.  Also agree I expect 462 will only be marginally better than 452.