31. DPR (Dynamic Power Reduction)
The DPR control allows the output power of the S1-200 to be reduced anywhere
from 200W (100%) down to 20W (10%) of the rated power.
DPR works by controlling the power supply voltages to the KT88
output valves and also the level of drive signal into the power
amplifier stage. Importantly, there are no components placed in
between the output valves, the output transformer and the
loudspeaker – a relationship which is essential in the delivery of
valve tone.
In addition to reducing the output power of the S1-200, the DPR
system actually controls the amount of power amplifier
compression too. Power amplifier compression is a key
ingredient in the characteristics of low powered valve amplifier
tone and gives a very playable 'feel' to the S1-200 at reduced
power settings.
We would recommend experimenting with the channel Gain and Volume, Master
Volume and DPR Control to achieve various combinations of preamplifier and power
amplifier distortion / compression.
Note: Generally speaking the more DPR is applied (i.e. power is reduced) the more
dynamic compression and power amp clipping will be experienced at any given
volume.
Clean DPR Operation
The DPR control is extremely powerful in fine-tuning the exact dynamic compression
characteristics of the power amplifier.
Channel
Channel
Channel
Master
Gain
Volume
Volume
Clean
Low
Mid
Mid
Clean
Low
High
High
Clean
High
High
High
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DPR
Description/
Sound Character
High
Maximum pre and power amplifier
headroom yields extremely dynamic
clean sounds.
Low
Increasing drive to the power amplifier
and reducing output power gives a
compressed clean sound rich in power
amplifier induced harmonics.
Low
Higher channel gain further increases
the power amplifier drive producing a
'full stack' crunch tone at only 20W
output power.
Crunch DPR Operation
The DPR control allows you to pin-point exactly how much valve overdrive you want
to come from the preamplifier section and how much is coming from the KT88s in
the power amplifier section.
Channel
Channel
Channel
Master
DPR
Gain
Volume
Volume
Crunch
Low/Mid
Mid
Mid
High
Crunch
Mid
High
High
Mid
Crunch
High
Mid
Mid
Low
Overdrive DPR Operation
The DPR control allows you to add power amplifier compression to your high gain
lead and rhythm tones. This is superb for encouraging really fluid lead playing rich in
power amplifier sustain and feel.
Channel
Channel
Channel
Master
DPR
Gain
Volume
Volume
Overdrive Mid
Mid
Mid
High
Overdrive High
Mid
Mid
Low
32. Power Indicator Light
The power indicator will light when the amplifier is switched on.
33. Standby
This switch enables the output stage. Always turn this switch on at least 30 seconds
after the Power switch (34). During short breaks in playing use just this switch to
turn 'off' and 'on' the amplifier's output.
34. Power
This switch is used to turn the amplifier on and off. You should always turn this switch
on before turning on the Standby switch (33).
Description/
Sound Character
Lower gain settings provide a dynamic
crunch utilising the full 200W of
available headroom.
At these settings there is a blend of the
distortion and compression generated
in the preamplifier and power amplifier
valves. We recommend that you
experiment to find your 'sweet-spot'.
Here maximum preamplifier gain is
combined with the lowest power
amplifier output for maximum valve
saturation.
Description/
Sound Character
The maximum headroom from the
KT88 power amplifier will yield
incredibly tight and dynamic overdrive
at extreme volume settings.
With maximum overdrive gain there is
loads of sustain from the preamplifier
which is augmented by the increased
power amplifier compression as the
DPR is set to minimum. Again, we
recommend that you experiment to find
your 'sweet-spot'.
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