Help PASS newbie - speakers LS3/5a

Can anyone help me understand the difference between the Aleph 3, Aleph 30 and the Zen 4.

I am using LS3/5a speakers for this application which are not effecient and like about 20+ watts with my tube stuff. A Dynaco St-70 is fine with them. I listen to vocal - acoustic music for the most part.

I would love to build the Zen but only if the result is as good as the others and there is enough power.

By the way can someone compare the sound of these to say a Dynaco ST-70?

Thank you all,


Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
The Aleph 3 and 30 have the same basic ratings and some
hardware differences. The Zen 4 has some similarities, but
is lower powered and capacitor coupled. It has two gain
stages also, but the input stage is just a follower / buffer for
the capacitance of the power Mosfet, where the first gain stages
of the Alephs are more traditional differential pairs of Mosfets.
The Aleph 3 and Zen 4 have single-ended inputs, and the
Aleph 30 also has balanced inputs.