Koch Twintone Mark III OPERATING INSTRUCTIONS [en, de, nl]

TWINTONE

Mark III

OPERATING INSTRUCTIONS GB
BEDIENUNGSANLEITUNG DE
GEBRUIKSAANWIJZING NL

 2012 Koch Guitar Electronics

EC DECLARATION OF CONFORMITY

We, Koch Guitar Electronics, Neonweg 27, 3812 RG Amersfoort, The Netherlands, declare
under our sole responsibility that the product:

TWINTONE-III Guitar Amplifier

to which this declaration relates is in conformity with the following harmonized standards:

* EN 50081-1 (1991) Electromagnetic compatibility. Generic emission standard.

Part 1 : residential, commercial and light industry;

* EN 50082-1 (1991) Electromagnetic compatibility. General immunity standard.

Part 1 : residential, domestic and light industrial environment;

* EN 60065-1 (1993) Household electronic apparatus.

Part 7 : Heating under normal operating conditions;

* EN 60335-1 (1988) Safety of household and similar electrical appliances.

Part 1 : general requirements.

following the provisions of Council Directive 98/336/EEC on the approximation of the laws
of the Member States relating to electromagnetic compatibility and the provisions of Council
Directive 73/23/EEC on the approximation of the laws of the Member States relating to low
voltage and electrical safety.

Amersfoort, 21 February 2012

Dolf Koch

Front panel

Clea n Ch anne l

Normal

10

Bright Clean

Inputs

0

Volume Bass Mid Treble

1 4

2

+5

-5

+5

-5

+5

-5

3

Back panel

115 230

~

VAC

HT Fuse

T500mA

Footswitch Manual

OverdriveFS-4

Channels

On

Off

Power

100

100 Watts, 50/60Hz

Fuse: 100/120V - T3.15A

220/240V - T1.6A

Boost

Clean

0

5

Volume

0

Reverb

(FX Mix)

Over dri ve Ch anne l Mast er

10

10

0

6

+5

-5

+5

-5

+5

-5

7

CONNECT SPEAKERS BEFORE USE !!!

Effects Loop

To FX-in

10

Serial

From FX-out

Parallel

W W WW

1x4/2x8 1x8/2x16 16

Output Power 50 Watts

Speaker Outputs

10

0

PresenceTrebleMidBassVolumeGain

10

0

Rhythm Solo

0

10

8 9 10 11

CAUTION

RISK OF ELECTRIC SHOCK

!

Speaker

Emulated

output

REC/PA

* Disconnect Power Supply before changing Fuse
* No User Serviceable Parts inside
* Refer Servicing to Qualified Personnel only

Serial #:

Electronic design: Dolf Koch

Output transformer: Vanderveen design

Styling: Marijn van der Maat

Made by: KOCH GUITAR ELECTRONICS

Amersfoort, The Netherlands

On

Standby

Twin tone

12

DO NOT OPEN

Mark III

1

3

4

5

6

8 9 10

7

112

E N G L I S H

Thank you for choosingthe TWINTONE-III from KOCH. You now own a "state-of-the-art" all-tube guitar amplifier of the highest quality.
The TWINTONE-III has been designed andbuilt by people who - from their ownexperience as musicians - take guitar sound and quality
very seriously. That is why this product was designed and built with the utmost care in order to meet all professional standards. Our goal
was not only to design an amp which sounds fantastic and is easy to operate, but also to build it in such a way that it will serve you loyally
for many years to come.
Please take your time to read this manual carefully before you switch on the TWINTONE-III and also please fill in the warranty card and
mail it. Thanks and lots of succes withyour new TWINTONE-III !

CAUTION:
* BEFORE PUTTING INTO OPERA-

TION READ THESE OPERATING
INSTRUCTIONS CAREFULLY.

* NO USER SERVICEABLE PARTS

INSIDE.

* REFER SERVICING TO

QUALIFIED SERVICE
PERSONNEL ONLY.

FRONT PANEL FUNCTIONS

[1] INPUTS

NORMAL - Input for standard instruments, e.g.guitars with single­coil pickups.

BRIGHT CLEAN - Input for high-output instruments,e.g. guitars with
humbucker pickups. This inputhas 6dB gain reductionto prevent
overload of the input stage and a filter which compensates guitar
cablelosses by boostingthehigh frequenciesas of 3Khz. (Due to
theirhighercoil impedance, humbuckerpick-ups suffer morefrom
cablelosses than single-coils, which may result in lack of sparkle in
the cleansound)

NOTE: The BRIGHT CLEAN input only influences the CLEAN
channel but does not affect the Overdrive channel.

[2] VOLUME: Controls thevolumelevel of the Cleanchannel.
[3] BASS, MID & TREBLE: Classic passive tone controls for the

Clean channel.
[4] GAIN BOOST: Selects Medium Gain for Crunchysounds (down)

or High Gainfor Lead sounds (up), inthe Overdrive channel.
[5] GAIN: Controls theamountof distortion in the Overdrivechannel.

A cleaner sound is achieved at lower settings (1-3). Atmiddle
settings (3-6) the sound will get more distorted and harmonically
richer. At high settings (6-10) high-gainoverdrive occurs with more
sustain and distortion.

NOTE: If the Gain Boost is switch on, squealingand/or
excessive hum and noisemay occur at high Gain settings,due
to microphonic guitar pick-upsand insufficient screening of
guitar-circuitry.

[6] VOLUME: Controls thevolumelevel of the Overdrive channel.
[7] BASS, MID & TREBLE: Classic post-distortion passive tone

controls for the Overdrivechannel.
[8] PRESENCE: Controls theamountof boost in theupper mid

frequency rangeof both channels.
[9] RHYTHM: If activated with the FS-4 Footswitch, thismaster

volumecontrol and can be preset at a lower rhythm level.
[10] SOLO: If activated with theFS-4 Footswitch,this master volume

controlcan be preset at a highersololevel.

NOTE: If theFS-4 Footswitch is not connected, the Solo Volume is
active.

WARNING:
* TO REDUCE THE RISKS OF ELECTRICAL

SHOCK, DO NOT REMOVE THE COVER.

* TO REDUCE THE RISK OF FIRE OR

SHOCK HAZARD, DO NOT EXPOSE

AMPLIFIER TO RAIN OR MOISTURE.
* THIS APPARATUS MUST BE EARTHED.
* TUBES ARE HOT.

DO NOT TOUCH DURING OPERATION.

[11] RED LAMP: Indicates that the PowerSwitch (back panel) is

switchedon.
[12] STANDBY SWITCH: Allows the TWINTONE-III tobe placed in

Standbyor Active(On) mode. In Standbymode the tubes remain hot,
but the amplifier is not operational.

BACK PANEL FUNCTIONS

[1] POWER SWITCH: Turns AC power On (red lamp [11] on) and

Off (redlampoff). When the switch is Off theamplifier is completely
shut down.

NOTE: When switching the amplifier on, leave the Standby switch
[12] in “Standby” position for 5-10seconds thus allowing the tubes to
heat up before switching to the"Active" mode.
When switching the amplifieroff, first select "Standby" [12] mode
and allow the amp todimcompletely before switchingthe power off.

[2] A.C. POWER:

INPUT - Power cordinput. The amp isequipped with a worldwide
power supply. Inside the amp amains selector switch can be set on
oneof threevoltages, 100, 115 or 230. Either of these voltages will
workworldwidewith minor power differences. The amp willworkon
either 50 or 60 hertz. After resettingtheinternal mains selector switch

make sure fuses are replaced with printed ratings on rear of
amp.

FUSE - Bothfuse and sparefuse are located on the sled of the
fuseholder. Fusesled can be removedwitha screwdriver. If the fuse
shouldfail, it mustbe replaced with the same type and value in

order to avoid damage to the amp and to prevent voiding the
warranty.

If theamp repeatedly blows fuses, check fora bad powertube.If
tube-failureis not the cause, the amp shouldbetaken to a qualified
servicecenter 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 onlywhen the power cord has been disconnectedfrom
its power source.

[3] HT FUSE: This fuse protects the powersupplyin case of tube
failure. If it blows, check fora bad powertube.If tube-failureis not
the cause, the amp should be taken to a qualified service center for
repair.