Koch Studiotone Bedienungsanleitung Seite 5

switch make sure fuses are replaced with printed
ratings on rear of amp.
FUSE: Both fuse and spare fuse are located on the sled of
the fuseholder. Fuse sled can be removed with a
screwdriver. If the fuse should fail, it must be replaced
with the same type and value in order to avoid damage
to the amp and to prevent voiding the warranty.
If the amp repeatedly blows fuses, check for a bad power
tube. If tube-failure is not the cause, the amp should be
taken to a qualified service center for repair.
WARNING: Only a qualified technician should attempt
an input voltage change. Personel injury or equipment
damage may occur if done incorrectly.
WARNING: The fuse should be replaced or the voltage
should be reset only when the power cord has been
disconnected from its power source.
[2] HT FUSE: This fuse protects the internal HT power
supply in case of tube failure. If it blows, check for a bad
power tube. If tube failure is not the cause, the amp should
be taken to a qualified service center for repair.
This fuse also must be replaced with the same type
and value in order to avoid damage to the amp and to
prevent voiding the warranty.
[3] REMOTE CHANNEL SWITCHING JACK: Provides an
input for the KOCH FS2-ST FOOTPEDAL (optional) or for
a remote channel switching unit, e.g. a MIDI switcher, and
automatically disconnects the 'Channels' switch [2] on the
front panel.
This jack is a stereo jack. The TIP controls switching
between Clean and OD, the RING between OD and OD+.
Both TIP and RING must be switched on/off to ground, to
realise channel switching.
[4] EFFECTS LOOP
TO FX (=SEND): This jack provides a buffered mono
output from the preamp of the STUDIOTONE and can be
used to connect an external effects unit. This jack must be
connected with the input of the effects unit (see also
CONNECTION DIAGRAM).
FROM FX (=RETURN): This jack provides an input for an
external effects unit and must be connected to the output of
the unit. When used, it disconnects the preamp of the
STUDIOTONE from the power amp and therefore it also
allows the STUDIOTONE to be used as a "satellite" for
other preamps.
NOTE: The EFFECTS LOOP's mode is serial. Its 10dBV
SIGNAL LEVEL guarantees compatibility with both
instrument-level effects like floor-pedals and guitar-
processors, as well as line-level effects like professional 19
inch rack mount devices.
NOTE: If the connection of an effects unit to the
STUDIOTONE gives more hum, a ground-loop may be
the cause of it.
[5] RECORDING SECTION
This section provides a mono output suitable for recording.
Its signal is derived from the speaker output so the typical
tube saturation of the power amp will be included; it also
includes Reverb and External Effects signals. This signal is
shaped by a special filter that simulates the typical
recording characteristic of a microphone placed in front of a
guitar speaker.
VOICING SWITCHES
These switches change the slope of that filter as follows.
LEFT-HAND SWITCH: This switch provides selection
between the placing of a microphone pointed straigth to the
centre of the speaker (axis) or pointed more to the edge
(off-axis) wich results in less bright sound very suitable for
recording of distortion sounds.
RIGHT-HAND SWITCH: This selector selects simulation of
the typical characteristics of either a 1x12 or a 4x12
speaker cabinet. The 4x12 position offers higher low-end
pressure and more low-mids.
OUTPUT JACK: This jack is an unbalanced output for
recording (or PA) and provides the filtered and voiced
signal as described above. The output signal is at line level
(-10 to 0 dBV).
[6] LINE OUTPUTS
DIRECT OUT: This jack provides an unfiltered and
unbalanced line output of the Speaker Output signal. It can
be used to input the signal from the speaker output of the
STUDIOTONE into the effects return jack of a second
guitar amplifier.
TO GUITAR AMP CLEAN INPUT: This unique output
provides the signal from the speaker output of the
STUDIOTONE, while it is compensated for sending it to the
input jack from the Clean channel on any guitar amplifier.
NOTE: Both these Line Outputs provide you with the
possibility to use a second guitar amplifier for increasing
the total volume of the STUDIOTONE's sound. If the
second amp is a different amp (not a Studiotone) a natural
stereo sound can be realised if both amps produce the
same amount of volume.
It is also possible to connect an effects unit between one of
the Line Ouputs of the STUDIOTONE and the
corresponding input of the second amp. This will open up
new ways for creating incredible stereo sounds.
NOTE: It is important that both amps produce their sound
IN-PHASE with each other. If they are NOT IN-PHASE the
speaker wires of one of the amps must be interchanged
(the + wire to the – lug of the speaker(s) and vice-versa)
NOTE: You can establish if both amps are IN-PHASE as
follows: Play through both amps simultaneously (without
external effects) and sit between them at ca. 1 meter
distance. If the sound seems to come from a point in
between the two amps, then the amps are correctly IN-
PHASE. If the sound seems to come from both sides, the
amps are NOT IN-PHASE.
NOTE: If the connection of a second guitar amplifier to
the STUDIOTONE gives more hum, a ground-loop may
be the cause of it.
[7] PHONES OUTPUT : Provided for the connection of a
set of headphones. The signal is filtered in order to
simulate the sound coming from the speaker.
NOTE: A set of low/medium quality headphones will give
the best results. High quality headphones may sound to
shrill with distortion sounds as a result of their extended
frequency response.
[8] SPEAKER OUTPUT JACKS: Provided for connection
of speaker(s) or speaker cabinet(s) with a minimum total
impedance of 4, 8 or 16 ohms. These output jacks can
NOT be used to connect multiple cabinets, one at each
output, you can only use one output at the time.
If a separate speaker cabinet is used, always use
speaker cable.
[9] SPEAKER ON/OFF SWITCH: This switch disconnects
the output of the amp from all three Speaker Ouptut jacks
and loads it with an internal 25W dummy load. This allows
you to play the amp at full power without hearing anything