2. amps-preamps
  3. 1036370656

Class A and B differences?

I have been auditioning the Pass Labs X-250 amp along with the Spectron Digital amp versus my Kinergetics KBA-75 power amp. My system consists of a Sony SCD-777ES, BAT VK-30SE preamp, B&W 803 matrix series II speakers, Acoustic Zen silver ref. ICs, Hologram speaker cables, JPS digital AC and power AC cords along with an Audience power AC cord. I hear the differences between the amps but I was expecting to hear larger differences, like a WOW what have I been missing. The Pass has more detail and seperation but maybe 10% max 15%. Is that the difference between a class A rated amp and a class B rated amp? Or is my Sony CD player or B&W speakers not up to the Pass amp capabilities?

Your comments are appreciated.
bigkidz

Showing 2 responses by muralman1

muralman1
1,527 posts
 
Listener is the first person I've heard to have the opinion Nelson Pass made better sounding amps in the past, meaning, I guess, the Aleph series. I own a Pass X-150 powering large ribbon speakers. The Pass X amps will faithfully pass along whatever you feed it. I don't like Sony, and wouldn't have one for my front end. I feel they sound too clinical. The B&W 803, a good rock speaker, does not have the resolving ability of an electrostat, panel, or ribbon speaker. I've been through a number of amps, and the Pass X amp proved to be a relevation. It doesn't sound like anything, really. It is substantially more dynamic than other designs I've tried. It's greatest achievment has been it's limitless sweet highs.

I just heard a Plinius 250 class A amp. I didn't learn anything about it because it was running some ancient speakers that colored everything. On the other hand, with my system's being ruthlessly transparent, any small change shouts out, wheher it be a tube switch or an amp switch. Most resently a visiting Llano failed to win my heart, to say the least.
muralman1
1,527 posts
 
I'm selling matched Mullards. These are being gobbled up by a lot of people. On my super transparent system, I found the Mullards to be objectionally colored. Why are they so popular?. On other less resolving systems, be it the fault of speakers, amps, pre amps, or front ends, the Mullards will assume a most pleasing lush sound. The point is, Bigkidz, if you move to more revealing speakers, you may find your older amp wanting. The Pass then, will have a much larger impact on your sound.

I found the speaker I wanted, and from then on I had to be very careful about my choices of component matches. Watching the used market carefully, I bought the X150, Aleph P, and Jolida NOS tubed 100 to feed my ribbons. The total outlay, including speakers, was about $6000.

What size room do you have Bigkidz?
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