Electrocompaniet ECP1 - Manual (Page 3)

The design features of ECP1 PHONO Preamplifier
After the Electrocompaniet 25 wa
tt amplifier had established a new standard for transistor
amplifiers, research was undertaken to find ways to make the amplifier even better, and to
extend its highly musical sound quality to more powerful amplifier designs. Only reducing
the commonly recognized types of distortion to low levels did not satisfy the engineers of
Electrocompaniet. They recognized that distortion appears in many forms, and that distort-
ion was still audible in listening tests even when conventional categories of distortion were
at vanishing low levels.
Traditionally, designers increased feedback to make a larger portion of the output signal
control the amplifiers response. Our listening tests showed us that simply applying more
feedback was not the answer. In fact, as one kind of distortion went down, other parame-
ters would be adversely affected, leading to an overall degradation of sound quality. We
knew that the other conventional design approach of eliminating feedback completely was
not the answer either, because this would cause high distortion levels, and as a result
“wooly” sound.
The answer to the dilemma was found in a novel approach to feedback theory. We
developed a feedback concept that allowed local feedback to be applied around indivi-
dual stages of the amplifier circuit. This approach allowed us to avoid the sonic
disadvantages of overall feedback from output to input. The concept was further developed
to reduce phase and interphase distortion between stages of the amplifier as well. We
were able to concentrate the loop feedback on the stages of the amplifier where it resulted
in audible improvement.
Stability margins were also expanded because feedback no longer affected the frequency
response. The use of this concept of individual gain blocks - complex in design but simple
in function - allowed us to reduce distortion to minute values in all the products.
Unpacking the preamplifier:
Immediately upon receipt of the preamplifier, inspect the carton for possible damage
during shipment. If the carton is visibly damaged, a claim must be filed with the carrier as
soon as possible.
Unpack the unit carefully, and please do remember to save all packaging materials for
future shipment. The carton and packaging have been designed to offer the safest possible
protection when transporting your amplifier, for the prevention of damage to the unit.
The content of the carton is as follows:
1 pc
s ECP1 Phono Preamplifier
1 pcs Electrocompaniet AC adapter
1 pcs Owners Manual