7
Parametric EQ Section:
The top row, going from left to right, is as follows: frequency sweep (low to high mid-
range), level of cut or boost (-12db to +12db), and bandwidth (two octave range).
The bottom row, from left to right, is as follows: frequency sweep (high mid-range to very
high frequencies), level of cut or boost (-12db to +12db), and bandwidth (two octave
range).
The reason why the EQs are called fully parametric is because they offer control over the
bandwidth of the cut or boost. This means that when you choose to boost a frequency,
say 4kHz, you have chosen the center frequency of the boost. If you choose to set the
bandwidth control to the left (the wider looking mountain) you will be creating a nice
smooth boost because you will be creating a gentle EQ curve. Broadband boost is the key
to classic tube equalizers. By contrast, when a narrow band cut is necessary, you can pull
out specific frequencies and leave the rest of the frequency range untouched. For
example, you can pull out some 500 Hz from the midrange and leave the lows and highs
intact if you set the bandwidth towards the right (the narrow mountain) because you are
creating a narrow cut. Obviously, the bandwidth can be swept to find the sound you are
looking for. Usually the degree of cut or boost will be fairly conservative if the
appropriate bandwidth is found. This is because you will find after some experimentation
that you are finding just the spots you want to EQ.
The DB 680 preamp was designed for the studio and the road.
The five-position selector switch on the back of the unit has three +4 settings (line level)
and two mic-level settings. The line level settings (0, +2 and +4) provide the appropriate
output level for any bass, from a vintage Fender to a modern bass with hot output levels.
Use these settings to go straight to any line input or fader inputs in the studio. If you are
going to a mic-pre on a live show console you can use the -40 pre or post EQ levels. The
-40 pre-eq does not send the signal through any of the tube gain stages. The -40 post-eq
setting uses the tube gain stages and the EQ section.