Pass x250.8 vs Boulder 850 vs Spectral DMA250

What I said it is a personal thing. I heard many Boulder
amps in the last 7 years. There was not even one time that I
thought: this is great I want it. I would not even want it
for free in my room!!

It never gave me the emotion I want in music!!

"It never gave me the emotion I want in music!!"

I thought you want 3D? No more? Now you want emotion? You keep changing.

Hi Max65.

I would say the best amp of the three you mentioned for the Sonus Faber Elipsa Red is the Spectral DMA250 being BJT (bi-polar)output it can almost double it's wattage for each halving of load impedance all the way down to 2ohms, and that means it can do current better than the other two which are Mosfet and cannot do the doubling act like the Spectral can.

Your Sonus Faber Elipsa Red are magnificent speakers but are a pig of a load in the bass region and demand an amp that do current, even though they are 91db efficient.

Quote from Stereophile:
"Though this is slightly lower than the specified 91dB, the shortfall is not important. While it will therefore require less of a voltage swing to play loud, the speaker is still a demanding load for the partnering amplifier, with an impedance magnitude that drops to 2.5 ohms throughout the upper bass (fig.1). There is also a punishing combination of 4 ohms magnitude and –50 ° electrical phase angle at 70Hz that will suck gobs of current from the amplifier."

And that -50% phase angle could mean a load down to even 1ohm at 70hz.

Cheers George

Thanks for everyone contribution.
Just to be focused on my genres they are both 50% rock and jazz, not so much classical music.
Now I own a C2500 preamp because my intention was to go with a MC452 amp, and I can't exclude now the C2500 will be an intermediate solution.
@Zd542: I partially agree with you about the possible degrading of SQ using different solutions due to a couple of facts I experimented in these days: the C2500 sound quality is very high compared to some friend's SS preamps and it is (suprisingly for me) neutral, and I'm not a fan of Mc gear.
Second, a good match, in my experience, can be completely unexpected as this little class A ss amp that changed my vision, even with its limits, and convinced to me to try the solid state way without Mc output autoformers (slam, nuances, etc.)
I'm coming from a Vitus RI-100 it was a good integrated amp but not so fast and with a little roll-off on bass area.
@George, sure I will try the DMA 250 even if it not the bes coupling with a non-spectral preamp. Thanks fory your contribution about phase and angle.. yes the SF Elipsa Red needs a lot of (good) power.
@Audiolabyrinth,@Bo1972 I mentioned Boulder because in Italy the same Spectral dealer is also Boulder dealer, I know him very well so it is easier to ask him the equipment for home testing. My only concern about Pass is I don't want another Vitus, and as far as I remember they are very similar in sound presentation, but it is only memory, I need to listen them again ;-)

I will also try to listen some recent Krell stuff like the evo series, but the 402 evo is too big in depth for my shelf (take a look on my system pictures). So the 302 is the only ooption.

Any suggestion will be welcome. After my holidays I will do the auditions in my home, end of August or after September 10th. And of course I will tell you my preference best matching my actual system.

The thing is, when you audition a lot of stuff, you remember all the good things. As a perfectionist at the end you want it all.

All parts you judge an amp for, need to be exeptional. When you have done a lot of lestiening, you are able to listen to all different parts in a very short time. Most people who have this as a hobby, can often listen to a few of these parts at one time.

Beside this, audio always will be a personal matter.