"Pete"

I am looking to build an amp for home theatre/hifi use.
currently have an amp using Hitachi's default design for mos fets from the
'80's ( 2sk49 2sj50 I think ).

** Those are Hitachi's famous TO3 pack " lateral " mosfets as used in many
famous hi-fi and professional power amps.

They are extremely easy to use, exceptionally rugged and have NO issues
with biasing or bias stability. Plus they will share current automatically
when used in parallel.


I plan using LM4702 but have three options for the output stage.

bipolar
SAP15P and SAP15N
2SA1943 and 2SC5200

mosfet
2SK1530 and 2SJ201


** Those Toshiba numbers are NOT lateral mosfets at all - but switching
types with a low gate voltage threshold.

Such devices do not have any of the desirable characteristics of the Hitachi
laterals.

Biasing is a pig, thermal runaway is just itching to happen.


..... Phil