9
4.5. Warning
Not respecting the rectifier mode selection procedure or the power level mode selection
procedure can damage your amplifier.
4.6. Cut control
The human ear does not perceive the tonal spectrum equally at low and high volume settings.
More specifically, high frequencies –which are generally enhanced with distortion-, can become
overwhelming at high volume.
The Cut [4] control allows you to tame the high frequencies, giving a more pleasing tone at high
volume settings. This control can also be used to focus on mids and bass.
5. Distortion types
Before reviewing the operation of your amplifier, here is a short technical description of the
different types of distortions. This will help you better understand the specificities of tube
amplifiers, and therefore help you get the best out of your
Sparkle
.
An amplifier is built around 3 main blocks:
the preamplifier, which shapes the signal of your guitar (through the tone settings, boost
etc…) and amplifies the signal’s voltage
the power amplifier, which amplifies the current of the signal retrieved from the
preamplifier, and sends it to the load (i.e. your speakers)
The power supply, which converts the 230VAC voltage into voltage levels appropriate to
power the preamplifier and the power amplifier.
Each block uses different tubes, and each tube is used in a different way. When the tubes are
‘pushed’ in certain conditions, they produce this very specific and sought-after ‘tube’ distortion.
But you surely got the point: each of the afore-mentioned blocks produces a tone-wise specific
distortion :
preamplifier : the design of this block sets the type of preamp distortion : ‘warm’ or
‘low-gain’ for amplifiers designed between the 50s and the 70s; ‘hard’ or ‘high-gain’
after the 80s. In the ‘low-gain’ range, the dynamics of the amp are enhanced: this is
particularly well-suited for jazz, blues and light rock. In the ‘high-gain’ range, the tone is
more compressed and offers a great deal of sustain, which is ideal for more aggressive
styles, namely hard rock and metal. Generally speaking, the distortion is gradual: higher
