[jtwrace]

Can anyone tell me how these amp sound compared to each other?  I would be interested in the sonic differences.  Thank you in advance.

[TONEPUB]

Hi There:

Do you mean the Aleph 3?

The Aleph 3 was an older Nelson Pass design, but one of his sweetest sounding
amps.  It was a 30wpc design with just one gain stage, which contributed a lot
to the sound.

The X series amps are based on that design, but with a lot more output transistors
and an addl. gain stage (or perhaps two) they have a higher power output.

Many will argue that the new amps have lost a bit of the magic from the Aleph 3
but they still sound quite good.  I have owned the aleph 3, and currently own
a First Watt F3 and have heard the X-250, but not side by side.  I would say, if
you don't need 250 wpc, picking up a clean used Aleph 3 is a real joy!!

Im a huge fan of Nelson Pass though, so take that for what its worth...

Best of luck

[Berndt]

I've heard from a friend that the x-250 is the sweetest of the x-series.

[TONEPUB]

That is what I've heard as well.  Nelson Pass told me that the bigger you make a solid
state amp (more output transistors, etc.) the harder it is to keep the magic!

[PaulFolbrecht]

That is what I've heard as well.  Nelson Pass told me that the bigger you make a solid
state amp (more output transistors, etc.) the harder it is to keep the magic!

Undoubtedly true.  The most magic is with ONE output device per channel which is yet another reason why single-ended triodes retain so much musicality (even parallel SETs with two tubes per channel lose something).  Can't pull that one off with transistors, unfortunately (tho Pass makes perhaps the best sand amps on the planet and they sound lovely).

[NealH]

I owned the Aleph 30 which was the successor to the Aleph 3.  The Aleph 30 was cleaner and more transparent than the Aleph 3.  More neutral.  By the same token, it was not quite as warm and comfy sounding as the Aleph 3.   The Aleph 30 used a very similar circuit topology to the "X" series amplifiers.  So, while I did not own the X-250, I believe that they share similar tonal characteristics.  But, I am speculating here as I have not owned the X-250 or, any "X" series amplifiers.  

The newer "XA" series was suppose to combine the best characteristics of both the original Aleph series and the more starkly neutral "X" series.    I have not owned an "XA" series amp either so, I can not comment on it's tonal characterisitics.  But, my advice would be to go in the "XA" direction if possible unless you have a softer or more laid back speaker.