Difference between Forte Model 2 and Model 40?

Anyone have any idea on internal build differences or sound?
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The Forte model 2 preamp uses an Op Amp for the phono stage and an additional Op Amp for the line stage. The Forte model 2 is a good preamp with no major sonic flaws, except that it could with a bit more in the way of dynamics.

The design of the Forte model 2 is not characteristic of Nelson Pass because discrete transistors are not used. Nelson Pass likes a matched differential pair of discrete FET's on the front end and bi-polar transistors on the output section. Also, another signature of Nelson
Pass design is that he likes to run the discrete transistors
in class A mode. In the class A, a transistor amplifies 360
degrees of a waveform.