Koch Jupiter - Handbuch (Seite 5)

JUPITER BACK PANEL
[1] A.C. POWER:
INPUT: Power cord input. The JUPITER is equipped with
a worldwide power supply. Inside the amp a mains
selector switch can be set on one of three voltages, 100,
115 or 230. Either of these voltages will work worldwide
with minor power differences. The amp will work on either
50 or 60 hertz. After resetting the internal mains selector
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 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] EFFECTS LOOP:
TO FX (=SEND): This jack provides a buffered mono
output from the preamp of the JUPITER and can be used
to connect an external effects unit. This jack must be
connected to 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 effects unit. When used, it disconnects the preamp
of the JUPITER from the power amp and therefore it also
allows the JUPITER to be used as a "satellite" for other
preamps.
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 JUPITER
gives more hum, a ground-loop may be the cause of it.
[3] SPEAKER OUTPUT JACKS: Provided for connection
of speaker(s) or speaker cabinet(s) with a minimum total
impedance of 4 ohms.
The output power changes with different loads as follows:
50 Watt: 1x 4 ohm or 2x 8 ohm speaker/cabinet
45 Watt: 1x 8 ohm or 2x 16 ohm speaker/cabinet
35 Watt: 1x 16 ohm speaker/cabinet
The Combo has an 8 ohm internal speaker, so its second
jack can be used to connect an extension cabinet of 8 or
16 ohms.
If a separate speaker cabinet is used, use KOCH
Dynacon SC608 speaker cable for the best results.
DO NOT USE GUITAR CABLE.
The JUPITER can be used safely without a speaker
connected, for example in a direct recording situation.
Disconnecting the speaker(s) will NOT cause any
damage to the amplifier.
[4] RECORDING OUTPUT JACK:
This jack provides an unbalanced mono output suitable for
recording or PA. 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 at line level (-10 to 0 dBV) and is
shaped by a special filter that emulates the typical
recording characteristic of a microphone placed in front of
a guitar speaker.
[5] FOOTSWITCH JACK: Provides an input for the
included KOCH FS2 FOOTPEDAL or for a remote channel
switching unit, e.g. a MIDI switcher. When the FS2 or the
remote unit is plugged in, the CHANNELS switch [6] is
automatically disconnected.
This jack is a stereo jack.
The TIP connects with the left-hand button of the FS2 and
controls switching between the COOL and the HOT
channel.
The RING connects with the right-hand button of the FS2.
A unique feature is that the function of the RING can be
selected with the SELECTOR SWITCH next to this jack
input. In the DOWN position the RING controls REVERB
ON/OFF, in the UP position the RING controls GAIN
BOOST of the HOT channel (and disconnects the Gain
Boost switch [4] on the front panel).
[6] CHANNELS SWITCH: Selects the COOL or the HOT
channel if no external channel switch (e.g. the FS2
footpedal) is connected to the FOOTSWITCH jack [5].
REPLACING TUBES
The JUPITER has two 12AX7 tubes. These tubes behave
like strings, they lose highs, lows and dynamics and after
a period of time they have to be replaced to maintain the
amps best performance. Exactly when is hard to say but
this is an indication: if you play almost every day change
tubes each year, if you play once or twice a week change
tubes every 2-3 years.
Preamp tubes rarely fail. If they are bad, these might be
the symptoms:
- Microphonic whistling or squealing on one or both
channels.
- No or low amp volume on one or both channels.
- Excessive noise on one or both channels.
- Excessive hum on one or both channels.
Changing a tube can be a simple and quick fix for most
problems in your amp.

SAFETY FIRST: DISCONNECT THE POWER CORD
FROM ITS POWER SOURCE AND LET HOT TUBES
COOL.

REPLACE TUBES ONLY WITH ORIGINAL KOCH
HIGH QUALITY TUBES. (IF OTHER TUBES ARE
USED THE WARRANTEE OBLIGATION EXPIRES)
If you have any doubts, please take no risks and let a
qualified technician do the job.