Koch Pedaltone II - Handbuch (Seite 5)

[15] TO FX RETURN: For connecting the
PEDALTONE II to the effects RETURN jack from the
Effects Loop of an external guitar amp head or combo.
This guitar amp will now serve as a power amplifier for
the PEDALTONE II (including speaker or speaker
cabinet); the amp’s preamp section will be
disconnected.
[16] HEADPHONES OUTPUT: Provided for the
connection of a set of headphones. Before reaching
this output jack, the signal is led through a filter that
simulates the sound picked up by a microphone in front
of a guitar speaker or speaker cabinet.
[17] REC/PA: This jack allows sending of an
unbalanced, filtered, signal to a Recording or PA mixing
console. The signal from this output is filtered the same
way as [16].
[18] CHANNEL-1 ENHANCE MODE ON/OFF:
determines if footswitch [11] will activate the
ENHANCER on the Clean channel (CH-1).
[19] GUITAR INPUT: Input for an electric guitar.
[20] TO CLEAN INPUT: For connecting the
PEDALTONE II to the input jack of an external guitar
amplifier. If this amp has a channel selector it must be
switched to the Clean channel.
[21] EFFECTS LOOP TO FX (=SEND): This jack
provides a (buffered) mono output from the preamp of
the PEDALTONE II and can be used to connect an
external effects unit. This jack must be connected with
the input of the effects unit.
[22] EFFECTS LOOP FROM FX (=RETURN): This jack
provides an input for an external effects unit and must
be connected to the output of the unit. It automatically
disconnects the preamp section.
NOTE: This is a serial Effects Loop. 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.
[23] POWER SUPPLY: Input for the included external
12VAC mains adapter.
REPLACING TUBES
 SAFETY FIRST: DISCONNECT THE MAINS
ADAPTER FROM THE PEDALTONE II AND LET
HOT TUBES COOL.
 CHECK THE ‘TUBE FUNCTIONS DRAWING’ FOR
THE CORRECT TYPE NUMBERS AND
LOCATIONS.
 REPLACE TUBES ONLY WITH ORIGINAL KOCH
HIGH QUALITY TUBES. (IF OTHER TUBES ARE
USED THE WARRANTEE OBLIGATION EXPIRES)
 BEFORE REPLACING TUBES, REMOVE THE
PROTECTION CAP FIRST.
 AFTER REPLACING TUBES, PUT THE
PROTECTION CAP BACK IN PLACE.
If you have any doubts, please take no risks and
let a qualified technician do the job.
[24] This protection cap can be removed, using the two
large black bolts on each side, for replacement of one
or more of the four 12AX7 tubes. The second tube (see
TUBE FUNCTIONS) should always be replaced with a
special low microphonic type (Koch 12AX7LM/7025).
Preamp tubes wear out and have to be changed from
time to time to maintain the PEDALTONE II’s best
performance. Tubes behave like strings, they lose
highs, lows and dynamics and after a period of time
they have to be changed. 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.
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.
Changing a tube is a simple and quick fix for most
problems in your PEDALTONE II.
Again, if you have any doubts, please take no
risks and consult your dealer and/or a qualified
technician.