Koch Guitar Electronics TWINTONE Mark III Operating Instructions Manual

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

1 4

5

6

8 9 10 11

12

2

3

7

1

4

5

6

8 9 10

112

3

7

Front panel

Back panel

Effects Loop

To FX-in

Reverb

(FX Mix)

From FX-out

Serial

Parallel

Fuse: 100/120V - T3.15A

220/240V - T1.6A

VAC

100 Watts, 50/60Hz

115 230

100

Volume

~

0

10

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

!

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

Standby

On

PresenceTrebleMidBassVolumeGain

Boost

Rhythm Solo

Normal

Bright Clean

Inputs

Volume Bass Mid Treble

Clea n Ch anne l

0

10

-5

+5

-5

+5

-5

+5

Over dri ve Ch anne l Mast er

0

10

0

10

0

10

0

10

0

10

-5

+5

-5

+5

-5

+5

Twintone

Mark III

Speaker Outputs

Footswitch Manual

Off

Power

On

OverdriveFS-4

Clean

Channels

REC/PA

HT Fuse

T500mA

Serial #:

Electronic design: Dolf Koch

Output transformer: Vanderveen design

Styling: Marijn van der Maat

Made by: KOCH GUITAR ELECTRONICS

Amersfoort, The Netherlands

CONNECT SPEAKERS BEFORE USE !!!

1x4/2x8 1x8/2x16 16

Output Power 50 Watts

W W WW

Speaker

Emulated

output

E N G L I S H

Thank you for choosing the TWINTONE-IIIfrom KOCH. You now own a "state-of-the-art" all-tube guitar amplifier of the highest quality.
The TWINTONE-IIIhas beendesigned and built by people who - from their own experience 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-IIIandalso please fill in the warranty card and
mail it. Thanks and lots of succes with your 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.

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.

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 input has 6dBgain reduction to prevent
overload of the input stage and a filterwhich compensates guitar
cablelosses by boosting the highfrequenciesas of 3Khz. (Due to
theirhigher coilimpedance, humbuckerpick-ups suffer morefrom
cablelosses than single-coils, which mayresult in lack of sparkle in
the clean sound)

NOTE: The BRIGHT CLEAN input only influences the CLEAN
channel but doesnotaffect the Overdrive channel.

[2] VOLUME: Controls the volumelevelof the Cleanchannel.
[3] BASS, MID & TREBLE: Classic passivetone controls for the

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

or High Gain for Leadsounds (up),inthe Overdrive channel.
[5] GAIN: Controls theamountof distortioninthe Overdrivechannel.

A cleaner sound is achieved at lower settings(1-3).At middle
settings (3-6)thesound will getmore distorted and harmonically
richer. At highsettings (6-10) high-gain overdrive occurs withmore
sustain and distortion.

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

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

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

frequencyrange of both channels.
[9] RHYTHM: If activatedwith the FS-4 Footswitch, this master

volume control andcan be preset at alower rhythm level.
[10] SOLO: If activatedwith the FS-4 Footswitch, this master volume

controlcan bepreset at ahigher sololevel.

NOTE: If the FS-4 Footswitch is not connected, theSolo Volumeis
active.

[11] RED LAMP: Indicates thatthePower Switch(back panel) is
switchedon.

[12] STANDBY SWITCH: Allows the TWINTONE-III to beplaced in
Standbyor Active(On)mode. InStandbymode thetubes remainhot,
but theamplifieris not operational.

BACK PANEL FUNCTIONS

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

Off (red lamp off). When the switchisOff the amplifier is completely
shut down.

NOTE: When switchingtheamplifieron, leave the Standby switch
[12] in“Standby” position for 5-10 seconds thus allowingthetubes to
heat up beforeswitchingto the "Active" mode.
When switchingthe amplifier off, first select "Standby" [12] mode
and allow the amp todim completely before switching the power off.

[2] A.C. POWER:

INPUT - Powercordinput. The amp is equipped with a worldwide
power supply.Insidethe ampamains selectorswitch canbeset on
oneof three voltages, 100, 115 or 230.Either of thesevoltages will
workworldwide withminor power differences. The amp willwork on
either 50 or 60 hertz. After resetting the internalmains selector switch

make sure fusesare replaced with printed ratings on rear of
amp.

FUSE - Both fuse and spare fuseare located onthesled of the
fuseholder. Fuse sledcan beremoved with ascrewdriver. If the fuse
shouldfail, it must be replaced withthesame type and value in

order to avoid damage to the ampandto prevent voiding the
warranty.

If the amprepeatedly blows fuses, check for abad power tube.If
tube-failure is notthecause, theamp shouldbetaken toa 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 only when the power cord hasbeen disconnected from
its power source.

[3] HT FUSE: This fuse protects the power supplyincase of tube
failure.If it blows,check forabad power tube. If tube-failure is not
the cause, the amp should betaken toaqualified service center for
repair.