Mcintosh MC402, Krell FPB 600 or Passlabs x250.5


Hi guys, need some advice on the above power amp option.

I'm currently using a pair of Sonus Faber Olympica II. It was placed in bedroom and only driven by Krell 400xi.

Now the setup has been moved to living hall and I'm getting a pre-power amp to drive the Olympica II as the krell 400xi obviously doesn't have enough juice. I've tried it with krell 400xi in living hall and the bass extension is just not there, even though I do like the soundstage, smooth mid / high that the 400xi is able to produce with the olympica.

Recently I came across a used Mcintosh C40, and it was always in my wishlist to one day try the mcintosh gear. I bought the C40 and now looking for a power amp to pair with it. Naturally, it would make sense to match Mac Pre with a Mac power, but I would like to open up for more option.

I know each of those three are distinct in their power rating, but I don't always listen at loud level. I listen to all genre of music, but probably spend more time on vocal songs.

Does anyone have experience pairing them with Sonus Faber with great result? In fact all of them cost about the same (I found used unit in my local dealer). Or there's other candidate that I should consider also?

Thanks!
nicholas_1213
I like both Pass and Krell amps, but I don't understand why McIntosh uses autoformers with their ss amps? The use of which compromises the advantage of linear frequency response that can otherwise can be inherent in ss amps with typical speakers.

Nicholas_1213 hi
Unsound is correct about the Mac.
It would be good to get hold of a impedance/phase graph of your speakers, this will then give a good idea for either the Krell or Pass. If your speakers are a hard load then the Krell would be the way, if not then either would do and will depend if you like Mosfet sound (Pass) or Krell sound (Bi-Polar).

This is mostly but not always the case depending on circuit and speakers.
Mosfets tend to be sweeter more laid back.
Bi-Polars more punchy and up front, can be just as sweet with lots of Class A bias.

Cheers George
Hi Unsound & George,

Thanks for your input. Yup I have read it on other forums as well regarding the autoformer. I guess it is either you love it or you hate it? If not looking from the technical perspective, I actually kinda like how the MC402 sound compared to the krell (no chance to listen to the Passlabs yet). The krell is impressive, full bodied, impressive punch and bottom end, smooth and detail sounding, but the mc402 sounds more 'relaxing' to me while not sacrificing those quality such as soundstage, details, transparent (yes to me it is quite neutral, non tube-like / coloured sound at all), and it is not SLOW at all like some have claimed the Mac amps are.

Probably at the end of the day when return home from work, I would find Mac sound to be more appealing. Krell is very strong competitor, and the fpb600 that I listened to, is not 'harsh' or 'dry' at all (again like what some other forumer have claimed to be). I would love to have the bottom end (bass) quality from krell to Mac, but guess we cant have best of both world (probably with much higher cost?) If I further add in durability factor, I guess both of them shouldnt give too much problem? Even though the krell class A runs much hotter..

For Passlabs, i have heard all good thing about Pass, but it is unfortunate for not having chance to listen to it. Over here it is also much rare item in used market compared to the other two..