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Moscode 401HR vs Pass Labs X150.5

So...for those that followed my previous thread, I am still in the hunt for the best amp under $2500 (after auditioning and returning a set of mono amps). I really have not been able to find much on the differences between these two amps sonically. I know the Pass has better resale value, but that's not my primary concern, although it is a concern for sure. The Moscode is rated at 200w into 8ohms (300 into 4ohms), the Pass at 150w (also 300w into 4 ohms I believe). I also know that Moscode improved upon the 401HR with the 402AU. Anyway, my tastes are bluesy rock, female vocalists and jazz. My system is as follows

AIFF lossless => Peachtree Nova USB DAC/Preamp => ??AMP?? => Dynaudio Contour S3.4 spkrs (4ohm load, 88db)

If anybody out there can offer comments as to how these two amps compare (or don't!) I would appreciate it. Thanks
fredorama
tvad
9,467 posts
 
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.
bondmanp
1,465 posts
 
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.
thesoundhouse
247 posts
 
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.
tvad
9,467 posts
 
I have yet to hear or read about any reliability issues with the Moscode 401HR. In this community, I would think any reliability problems with the latest Moscode amplifiers wold have surfaced.

I don't believe one can apply the reliability of Moscode amps manufactured 12 years ago with the latest offerings.
thesoundhouse
247 posts
 
I sure they are better today. They are still a Hafler designed output stage with a really good tube buffer or input stage. Look at how much stuff is tucked inside both the newer and older Moscodes. The caps are tucked sideways because of the tight real estate. Heat on amplifiers causes problems over time. I sure you are right they are more reliable today than from 12 years ago. Here is a link to a pic of a newer moscode amps. http://blog.stereophile.com/ces2009/moscode-450.jpg.
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