Pass Aleph 30 and 60

Sondeknz

I believe the answer to your question about power into speaker impedance is in circuit topology. Voltage gain stages vs. current gain stages. I don’t have simple details at hand since this information comes from reading lots of articles over the years.
Interviews with Nelson Pass about his circuits are plentiful on the Web and Mr. Pass speaks about things in a fairly straight forward and easy to understand way. I find them both interesting and informative. You may, as well.

Yes, "current source topology" is what the manual said, more power into lower impedence load than First watt Aleph J.

That's one of the differences among the Aleph 3 and 30 versus the First Watt designs. Though none would be ideal with difficult to drive speakers. 

I owned the Aleph 30, got it new on closeout for $1400, First Watt is way more, my how times have changed! 

It was a very good amplifier, It had qualities of tubes along with some of the pluses of solid state. Not the most practical though. High energy use. Ran really hot (which the manual says will cause semi-conductor failures and dry capacitors within 10 to 15 years of use, something to consider if purchasing used).

Also mentioned in the manual- "one hour to reach optimum performance", which I found to be true, you could actually hear the sound changing as you listen.

Nowadays I mostly use a Schitt Aegir (a more efficient quasi class A design that runs somewhat hot but not egg fry hot).

It is'nt quite as good as the Pass was, but has standby switch so it is ready to go out of the gate and has a shorter warm up time. Cost a little more than half of what the Pass did 20 years ago. 

 

I have owned an Aleph 30 amplifier for years and love it. It's been paired extensively with Audio Physic Virgo III speakers rated at 89db sensitivity. The pair are in a 14' x 18' room. I do not listen at levels much above 90db. No issue with power or control with this particular pairing.