Moscode 401HR vs Pass Labs X150.5

I owned the Moscode and it is very nice but be careful of the impedence (speakers). It is not recommended for 4 ohm speakers (even by Moscode...also see the Steriophile comments on the speaker impedence). My speakers are just a tad above 4 ohms and the result was a softening of the top end and a bit of looseness in the bottom. The mids were fantastic. I ended up preferring a solid state amp in my rig for the reasons mentioned above (put the tubes in the preamp). Just my thoughts....your experience may be different.

05-24-10: Jeffga
It is not recommended for 4 ohm speakers...

That's not accurate.

The quote from John Atkinson's Measurements section of the Stereophile review states:

The Moscode 401HR offers pretty good measured performance, though it is clearly not happy driving loads below 4 ohms.

The difference here being *below* 4 ohms. If you read the measurements section, you will see that the amplifier did fine into 4 ohms, but faltered into 2 ohms.

The OP's speakers have a minimum impedance of 4 ohms (even though they are marketed as 4 ohm speakers, which usually means 4 ohms *nominal*).

I don't believe the Moscode 401HR will have any problems with these speakers.

That said, I am not recommending the Moscode over the Pass Labs, or vice versa. The choice is an issue of subjectivity, IMO.

Never heard Pass, but the Moscode, which I've heard twice, sticks in my mind as an exceptional amplifier. One I would probably buy if I had the money. YMMV, of course.

Both are fine amps and do have sort of a similar sound. I have owned several older Moscodes in the past but do not miss the expensive repairs. I have owned 3 different Pass Labs amps and driven them with very difficult loads and never had a problem. The circuitry in the Pass is much more simple and stable. The more challenging loads seem to eat the Mosfets in the Moscodes and Haflers. It was 12 years ago, I had a pair of Infinity 8 Kappas and a moscode. I was very luck to find all the parts to fix my 8 Kappas when my moscode expired. It happend again 2 years later with a Hafler 9505 transnova. My technician friend said he was shocked that although both amps had different parts the output section was the exactly the same design. He also pointed out what made the Moscode sound so good was an exceptionally well designed and beautifully buit input stage. The Pass will sound as good or a little better but will be more reliable.