Page 8
SET 40
Owner's Manual
Amplifier Power and Loudspeaker
Selection
The
SET 40
has a nominal power rating of 37
watts for each channel. While this may seem
like a low power output compared to many
amplifiers on the market, because of the class A
operation, the low distortion, wide power
bandwidth, and the grace that these amplifiers
have when overdriven, they will produce as
much or more level sound than many 100 watt
amplifiers. We suggest that you consider any
loudspeakers with average rated sensitivity of
86-87 dB/Watt/Meter or greater. Greater
sensitivity will allow higher listening levels
before either the amplifier or the loudspeaker
runs out of steam. Remember that with many
speakers in even a relatively large room the
amplifiers will be operating at average levels of
only 1-5 watts each with typical music at quite a
high average sound level of 90 dB. This leaves
15 to 17 dB of amplifier headroom for musical
peaks.
We have successfully used the
SET 40
with
many types of loudspeakers, including dynamic
cone, planar magnetic and electrostatic types.
When choosing a loudspeaker many variables
come into play, therefore we will not attempt to
recommend a type or set of 'brands' which you
should consider. Our suggestion is that you
work with the dealer representing the
SET 40
and choose a loudspeaker which works well
for your tastes, in your room with your system.
A dealer which sells the
SET 40
will be more
than competent to guide you in your selection.
Amplifier Placement and Power-
on
When installing the amplifiers it is important that
they receive adequate ventilation. Allow at
least 6 inches above the amplifiers, and be
certain that the holes on the bottom cover are
open to air circulation (do not place them directly
on a thick carpet, as this will block the bottom
ventilation holes). Do not use the
SET 40
in a
closed cabinet unless fan cooling is allowed or
the amplifiers will overheat and could be
damaged. They generate consider-able heat in
operation because of their single-ended class A
operation. With adequate ventilation on an open
shelf or stand they will cool themselves through
convection and will not require any additional
cooling.
When the setup is complete and all connections
are made, the power cord can be installed and
the power switch turned to the 'on' position.
The amplifiers will be operational nearly
immediately, and they require only 15 to 20
minutes to reach optimum performance. There
will be a short break-in period of 20 to 30 hours
when the amplifiers are first used. The sound
quality potential will improve during this period
as all of the components and tubes 'settle in'
during this time. Further improvement in sonic
performance will occur during the first 100 to
200 hours of use as the copper wire anneals
and all of the components settle in.