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Names and functions for each part
Front Panel
1. Input and Sensitivity Switch
This is the Input to the amplifier and the switch controls the sensitivity and input
impedance of the first gain stage of the input section of the preamp. It is the bridge
between the guitar and the very first tube. The HI position inputs the guitar’s full
signal at about 1 M-Ohm input impedance whereas the LO attenuates the signal
about 6dB down from the HI position at an impedance of about 130 K-Ohm.
2. Gain Control
This controls the sensitivity of the input section of the preamp. At low settings
the preamp will be clean with a bright character. As you turn the control up, the
sound will become fuller and warmer (‘fatter’), with a more pronounced bottom
end. In the VINTAGE CHANNEL, this control creates a clean tone in the fur-
thest counter clockwise positions. Increasing the control clockwise increases
gain and drive. When the control is in the furthest clockwise positions, it pro-
vides a high gain overdrive, similar to that of a vintage stack type amplifier. In
the HOT Channel, this control works a bit differently. The maximum setting
saturates the signal and enhances low and low mid frequencies. While this
region provides the maximum saturation and therefore sustain, it also com-
presses and softens the attack and may cause feedback and instability so in
the HOT Channel, use this higher region of the GAIN Control sparingly and only
when maximum sustain is needed.
3. Bright Switch
This controls the high frequency normally lost to the GAIN Control in most amps.
It provides three types of response. The NORMAL position adds no highs back
into the sound. The BRIGHT position adds in subtle highs whereas the
BRIGHTER position adds enough high end to cut through anything. This switch
is directly related to the GAIN Control. The farther clockwise the GAIN Control
is, the less effect the BRIGHT SWITCH has.
4. EQ Controls
The EQ is a traditional passive type of network with the frequencies tweaked for
the Thermion. Basically, a simple rule applies...as the GAIN is increased the
EQ section has less and less effect on the signal until at maximum GAIN the
signal is so saturated that you are getting mostly Gain and very little Tone. For
this reason we suggest using the GAIN
Control sparingly and not past its middle region unless absolutely necessary.
Here the EQ section&qs very active and provides maximum tone shaping power.
The TREBLE Control is the most powerful of the three EQ controls, as it is first in
the signal path of these controls and is therefore the most dominant and power-
ful EQ control of the three. The MIDDLE and BASS both receive their signal
from it and is next in line only to the GAIN Control as a shaping tool. Too much
TREBLE will negate the effect of the other two controls. The optimum region of
the TREBLE Control is where ample top end is mixed in and yet enough signal
is still passed on to the MIDDLE and BASS Controls. The “sweet spot” of the
TREBLE Control in relation to the BASS and TREBLE Controls occurs in the
middle region (11:00 - 1:30).
The MIDDLE Control determines the blend of midrange punch. It also has a
great deal to do with how a sound feels to play. Setting the Midrange low scoops
the attack. Setting the MIDDLE higher introduces more punch. Setting the Mids
very high may make the sound “brassy”. Keep this in mind when dialing up your
tone. This control blends in the lower frequencies and its effectiveness, again,
depends on the setting of the TREBLE Control.
It should be set with moderation as extreme settings in either low or high directions
can produce an unbalanced tone. Be especially careful in higher Gain settings of
either channel. The BASS control determines how much low end is added to the
sound. Too much low end will cause a tubby or unfocused sound. Usually the
BASS Control is most effective in the middle region (around 11:00 - 2:00) however
these settings will vary with the amount of GAIN and TREBLE used.
5. Presence Controls
The PRESENCE control in the VINTAGE Channel is the traditional type in that
it works in the power section to modify attack and brightness. It works on differ-
ent frequency than the TREBLE Control, so depending on the amount of Gain
dialed up, can sound higher or lower than the Treble frequency.
The Presence circuitry in the HOT Channel is different than the VINTAGE Chan-
nel’s Presence circuit as it is located earlier in the pre-amp section. This PRES-
ENCE is a more aggressive control and is more suited for high-gain settings
6. Master Controls
These set the amount of signal generated by the preamp out into the power
amp section. When using very clean GAIN settings, you may want to turn this
up higher than when using higher GAIN settings.
HINT: Balancing the GAIN and MASTER controls can create many different
amp textures.
7. Channel Switch
This switch allows switching between the VINTAGE Channel and HOT Channel
when the footswitch is not plugged in.
8. Dampening Switch
This switch allows the user to choose either a traditional stack sound or more
radical aggressive voicing within the HOT CHANNEL by controlling the damp-
ening. When the dampening is on, the distortion is a more controlled “tradi-
tional” type. When the dampening is removed, the distortion is extremely heavy,
thick and aggressive. This switch works when the footswitch is not plugged in.
9. Send Control
This is the control that regulates the amount of preamp signal at the SEND jack
on the back of the amp. This in turn controls how much preamp signal is sent to
the effect processor.
10. Effect Loop Switch
This switch engages or disengages the series Effect Loop when the footswitch
is not plugged in. Engaging the Effect Loop without an effect plugged in can
provide additional post eq gain depending on the settings of the SEND and
RETURN Controls.
11. Return Control
This is the control that regulates the amount of effect processor signal at the
RETURN jack on the back of the amp. This in turn controls how much effected
signal is sent on to the power amp stage.
NOTE: If Send and or Return Controls are set off and Effect Loop is engaged,
NO SOUND will pass through the amp.
12. STANDBY Switch
This switch engages the high voltage DC to the tubes. Always power the ampli-
fier on using the POWER Switch with this switch in the STANDBY (down) posi-
tion. Wait for at least 30 seconds and then engage the STANDBY Switch into
the ON (upright) position. Powering up in this fashion will help to preserve tube
life. It is also best to put the amp into the STANDBY position when taking breaks.
13. POWER Switch
This switch turns the AC power on/off to the amplifier. Use it in conjunction with
the STANDBY Switch to properly power the amplifier on.
Illuminated Panel Indicators
14. VINTAGE CHANNEL GAIN and MASTER
These indicators glow when the VINTAGE CHANNEL is engaged.
15. HOT CHANNEL GAIN and MASTER
These indicators glow when the HOT CHANNEL is engaged. They alternately
change color when the HOT CHANNEL is toggled between Dampening ON/
OFF. DAMPENING OFF with the thickest distortion will display red and DAMP-
ENING ON will display green.
16. Effect Loop SEND and RETURN
These indicators glow when the Effect Loop is engaged.
17. STANDBY and 18. POWER
These indicators are both illuminated when the amplifier is fully powered on.
When neither is illuminated the amplifier is powered off. When the POWER
Indicator is illuminated but the STANDBY Indicator is not, the amplifier is in the
STANDBY mode.
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ENGLISH
