Frequency; Treble; Master - Mesa/Boogie Big Block 750 Owner's Manual

FRONT PANEL CONTROLS:

FREQUENCY:

This control determines the frequency range that the ACTIVE MID control will cut or boost. As mentioned earlier,
it covers a broad range that sweeps from the low midrange region to the lower treble frequencies. The control sweeps from 200Hz on
E N G I N E E R I N G
PASSIVE-MID ACTIVE-MID FREQUENCY

TREBLE:

The TREBLE is also an active shelving style control like that found in the BASS and again, it was chosen for its ability
to radically shape the upper harmonic region. Like the BASS, it also has a center Q point with harmonics above and below responding
in harmony as it is dialed for either cut or boost.
E N G I N E E R I N G
ACTIVE-MID FREQUENCY
TREBLE
BLOCK 750 players make the comment that just these controls combined with the GAIN create the best tone they have ever heard!
NOTE: As with the BASS control, may we remind you that a control of this type with its increased power should be used with finesse.
In the TREBLE'S case, almost more so, because higher frequencies seem louder to the ear and are generally more painful when set
to extremes. Another reason to use care is that high frequencies tend to increase the ambient noise floor when set too high. This is
then exacerbated if the 5 Band Parametric is combined for added top end boost. Dial with care and music in mind.

MASTER:

The MASTER control is the feed to the Simul State power section and determines the overall playing volume of the
BIG BLOCK 750. An optimum setting will be determined by the setting of the GAIN control as well as the entire tone control
MASTER
TREBLE
(Continued)
the low side to 2Khz on the high side - with 340 Hz riding the center, straight up at 12:00 on the
control. This sweepable band gives you pinpoint shaping power over the broad and usable midrange
spectrum and also allows some overlap at the extreme ends of the control with the adjacent broad
band BASS and TREBLE controls.
May we again remind you to use care and taste when dialing with this powerful control. Some fre-
quencies stick out or cut more than others, making it possible to add unwanted, unpleasant and even
dangerous, peaks or blow unbalanced holes in your sound. We suggest dialing in your sound with
the standard tone control array first and then using the ACTIVE MID circuit to fine-tune and subtly
enhance your sound.
As the control is increased past 12:00, it produces a 6db per octave rise in gain starting at 723Hz until
+20db is reached. From this point, gain remains constant at +20db for all frequencies above 723Hz all
the way out to 20Khz. This scheme lends a sweetness of sound while retaining all the necessary cut
and focus associated with a traditional passive TREBLE control. As this control is dialed below 12:00,
it begins a 6db per octave cut from 3.2Khz to the shelving point at 723Hz, where it continues to
attenuate all frequencies above 723Hz until - 20db is reached where cut gain remains constant until
the control reaches 7:30 (off). The ability to cut these frequencies more radically makes it possible to
obtain incredibly rich and warm old-school R&B and Jazz sounds that rival any recordings of the day.
This active shelving TREBLE control completes the rotary tone control string to create a powerful and
extremely accurate network to use as your fundamental platform. It's no wonder many first time BIG
network. All these controls affect the signal strength at the end of the preamp and can make the MASTER
control very sensitive.
NOTE: Remember to use with caution as the MASTER is the gas pedal for the massive power available.
We suggest a zero setting at each power up to avoid damage to speakers and ears.
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