Doepfer A-199 Spring Reverb - Manual (Page 6)

A-199 Spring Reverb System A - 100 doepfer
6
7. Position and assembly of the reverb
system / Power supply recommendation
The reverb system used in the A-199 consists in
principle of a transmitter (“loudspeaker”) and a recei-
ver (“microphone”) that are connected via a 3-spring
system. The movement of the “loudspeaker” is trans-
mitted to the “microphone” by the springs and gene-
rate in this way the reverb effect.
The receiver (“microphone”) is very sensitive to ma-
gnetic fields and has to be mounted therefore in a
position with minimal interferences caused mainly by
the transformer of the A-100 power supply mounted at
the rear panel of the frame.
For this reason the black reverb system is connected
with 2 RCA phono cables to the A-199 module. Pay
attention to the colors if you disconnect the reverb
system: red jack plug into red socket (labelled INPUT).
The fixed mechanical connection between pc board
and reverb system used in the first A-199 modules did
not stand the test.
Therefore one has to find out the best position for the
reverb system creating a minimum of hum noise. As a
clue the reverb system should be placed as far as
possible from the transformer of the A-100 power
supply (normally mounted at the lower right side on the
rear panel). Normally the top left position in the frame
is a good one but the rotation of the reverb system
affects the hum noise too. The best position depends
upon many factors and has to be found out by trial and
error. It is also possible to mount the reverb system
outside the A-100 frame. But we recommend this only
for fixed installations of the A-100 frame.
As soon as the best position is discovered the reverb
system is fixed with double-face self-adhesive tape or
screws and nuts at this position. One may use the left,
top, or rear panel of the A-100 frame to mount the
reverb system. If screws are used 2 of them are
sufficient. If necessary 2 holes have to be drilled into
one of the panels. If the top or bottom cover is used
the holes in the covers fit to the holes of the reverb
system.
Additonally the springs of the reverb system are pro-
tected during transport with foamed plastic material.
One has to remove this transportation protection be-
fore installing the module. In case that the springs stick
together one has to separate them very carefully.
Otherwise the module will not work correct.
As the hum noise is mainly caused by the magnetic
field of the power supply transformer we recommend
the usage of the special A-100 power supply with ring
core transformer (A-100PSU2) instead of the standard
power supply (A-100NT12) for all A-100 systems that
include an A-199 module.