Sony TA-E901

The simplified-and-not-so-big.
But-very-good-nevertheless.
And-much-cheaper, too.

2,5x Cheaper than the TA-E900, the E901 made the first step aside from the original pre-Esprit units... it had tone controls !
And LEDs aplenty, too.
And the "simple signal path" wasn't respected, although, true, custom-designed relays to switch inputs and functions made up for that - and the "Esprit" surely was encased in the mysterious epoxy-potted modules :-)

The head-amp is made of four complementary differential amplifiers connected in parallel, the eq amp is a dual-Fet differential with cascode bootstrap links, current mirror load and Darlington emitter-follower push-pull amp.
All this DC from input to output, of course.
The flat amp is like the circuit of the eq amp but for the first stage which is replaced by a 2SK244 Fet ; the active tone controls work through a pair of NE5532P op-amps.
All this DC from input to output, of course.

Potentiometers are ALPS' RK-40 (volume) and RK-27 (active tone controls) ; short of the ZP-1 used in the TA-E88B and TA-E900 and the resistor arrays of Tokyo Ko-On Denpa, these are the best pots around.

An excellent amplifier, easier to use than its bigger brother, but unfortunately never ever shown in its optional and extra-rare TAC-91 wood/marble enclosure.

The design of the source selector also was more in sync with the times when compared to the knobs & switches of the TA-E900 : this was named "Visual Communication Display" - sign o' the times.


A real E901 in its TAC enclosure here (with some caps exchanged).