9
To swap from one mode to the other without changing the rectifier mode, follow the ‘power
level mode selection’ procedure below:
1.
Put the amplifier on Standby : flip the Standby
[3]
switch in the middle position
2.
Wait for 30 seconds
3.
Put the amplifier in Stage or Home mode depending on the desired output power
level (see former chapter).
4.5.Warning
Not respecting the rectifier mode selection procedure or the power level mode selection
procedure can damage your amplifier.
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
Crunch Machine
.
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
gain settings will yield high distortion levels, which allows to easily set your desired
distortion level without changing the volume level.
