Power Select; Full Power; Watt - Mesa/Boogie Express series Owner's Manual

reAr PANeL: C & F
(Continued)
ONTrOLS eATureS

POWER SELECT:

As mentioned in the OVERVIEW, your Express features our patented Duo-Class™ Power which allows you
to switch between two power ranges that run in both a different Class of Operation and a different Wiring Configuration. You will only
find this powerful feature on MESA amplifiers and it allows you to tune the power section for volume, Tone and feel... optimizing its
response for higher volume gig applications or lower volume recording and inspiring practice sessions

FULL POWER:

The Full Power setting (50 watts in Express 5:50, 25 watts in the Express 5:25) runs in Class A/B and is wired in
a Push-Pull Configuration. This position (switch up) delivers the full rated power and would be the choice any time you need headroom
for clean sounds or bold, tight authority for all the sounds while playing with other people. Class A/B, when combined with a pair of
output tubes wired in a Push-Pull configuration, is the most efficient operating class and style of wiring and this scheme emphasizes
upper mid punch, low-end clarity and upper harmonic cut.
Express 5:25 Express 5:50
NOTE: 5:25 Owners! You've probably noticed by now that your Express seems far louder and more dynamic than any other 25 watt
amp you've heard. This is due to Dyna-Watt™, our patented way of wiring up a pair of EL84 output tubes that delivers a massive
burst of headroom at the initial attack of the note. From there a "timed sag" circuit loosens the feel as the notes decay and the result
is a little amp that is twice as powerful as its rated wattage on the attack – where you need it – but sweet and clippable, bouncy and
dynamic as the sound decays. The Express 5:25 with Dyna-Watt™ is one of our most enjoyable circuits to play as it is extremely
Expressive and friendly feeling on the strings as well as incredible sounding...5:50 owners, check one out sometime!

5 WATT:

This position (switch down) reconfigures everything in your power section! The operating Class is switched to Class A,
which is far less efficient - but produces smooth, rich, silky harmonics and warm low end. Many vintage amplifiers were built with this
operating class. Now here is where we get tricky and is the basis of our patent. The wiring configuration is switched as well - from
Push-Pull to Single-Ended. This configuration - the first way tubes were ever wired – is again far less efficient but puts emphasis on
the even order harmonics. These are the second harmonic that lives one octave above the notes that are being played and they're
the most pleasing of all harmonics. They sound sweet and add a fullness to the sound like no other, almost like a super subtle octaver
that is way back in the mix. Push-Pull circuits cancel out this second harmonic when the wave form is split in half and each half is
amplified separately and the sweet second harmonic is replaced by the punchier odd-order third harmonic...thus the substantially
louder impact of the Push-Pull configuration. Use the 5 WATT setting anytime you want the sweetest little amp response at home or
in the studio. It produces gorgeous clean sounds at very low volumes and when pushed, clips in the coolest way...even beyond our
favorite vintage classics.
The tone and versatility of this two mode power section leaves most other circuits pretty lacking. It's truly like having two amps in
one package. And when you start combining the power choices with the myriad of sounds in the two Channels, the possibilities for
inspirational sounds are endless. Experiment and Enjoy!
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