PAGE 9
FRONT PANEL: Controls & Features (Continued)
The PRESENCE Control is a high frequency attentuator that is placed at the end of each channels pre-amp stage
and affects frequencies higher than those of the TREBLE Control. It acts independently of the other rotary tone controls and is cru
-
cial in voicing the channel. It is a powerful global tone control. Lower
PRESENCE Control settings darken and, in fact compress the
signal which works well to fatten single note solo sounds, giving them girth and focus. Some of
the best lead sounds in your
ACE will find the PRESENCE Control in its lower regions, where
a balanced, vocal response is achieved.
Higher settings unleash the mighty roar of your
ACE and this can be great for sparkling clean
sounds in Channel 1 and more aggressive crunch rhythm sounds in the high gain modes. Be sure
to taunt the beast that lurks in the CRUNCH mode of Channels 1 and 2 as the
PRESENCE is
truly amazing in this most agro mode.
This control is the master feed from the end of the pre-amp to the driver stage and the Effects Loop. As you can see
each Channel is fitted with its own
MASTER Control, enabling the channels relative volumes to be matched regardless of their ex-
tremely different sound styles and gain signatures. The
MASTER Control makes possible a wide range of sounds through its ability
to use very low
Gain sounds at high volumes and conversely, high Gain sounds at low volumes and everywhere between.
Again, we suggest using the
MASTER Control in its sensible ranges (9:00 - 2:00). Here, the chan-
nels will be easier to match with each other and the Effects Loop will see more reasonable signal
levels.
NOTE:
Because the MASTER Control creates the send to the Effects Loop, extreme settings
will cause a large signal to be sent to the Loop for that Channel. Not only may this cause possible
overloading of the processors Input stage, but will make balancing the two channels’ Effect Send
level difficult.
These channel specific switches determine the type of rectification the power section
of your
ACE will operate on. The choices are the solid state SILICON DIODES which convert the A.C. to D.C. with a constant stiffer,
tighter character or, TUBE RECTIFIER which brings online a 5U4 rectifier tube for a saggy, compressed power
feel. This patented switchable choice of rectification is at the heart of being able to nail the sounds we all hear
as classics and imparts a feel on the strings like no other element in a guitar amplifier. Tube rectification is
especially important when trying to dial-in vintage type sounds where - in the era before MESA introduced
the world to the high gain preamp, power clip characteristics were the only way to get a heavier sound. As
the power section tries to draw more current at higher volumes, the tube rectifiers begin to sag and compress
the sound while scooping the harder midrange frequencies, creating an ultra expressive power signature.
Solid state rectifiers do the opposite and deliver a steady, stiff supply of current - enabling the power section
to crank out its rated wattage with immediate response and tight authority.
TUBE RECTIFIER would likely be the choice for single note soloing where each note morphs through the vowel sounds as the dynamic
content changes from attack to decay. The SILICON DIODES will keep bass frequencies tight and track better at extreme preamp
gain settings, especially when detuned or at higher volumes, and emphasize attack and urgency.
The Switchable Rectifier feature is a huge part of the success of our entire Dual Rectifier line and has elevated them to their cur
-
rent status as iconic classics.
RECTIFIER SELECT: Diodes / Tube Rectifier
MASTER
DIODE
TUBE
DIODE
TUBE
FT
SW
CH 1
CH 2