At KV2 Audio our vision is to constantly develop
technologies that eliminate distortion and
loss of information providing a true dynamic
representation of the source.
Our aim is to create audio products that absorb
you, place you within the performance and deliver
a listening experience beyond expectation.
Contents
JK1 - Active DI BOX - Line Driver 4
Features 4
Specications 5
Connection 5
JK2 - Stereo DI BOX - Line Driver 6
Features 6
Specications 7
Connection 7
JKA - Acoustic DI BOX - Line Driver 8
Features 8
Specications 9
Connection 9
JKP - Passive DI BOX - Transformer Balanced 10
Features 10
Specications 11
Connection 11
JKT - Tone Generator 12
Features 12
Specications 13
Connection 13
Warranty 14
Service 14
JK - series
Named after company founder and chief engineer, George ‘Jiri’ Krampera, the JK Series of DI Boxes and
Audio Tools retain KV2’s philosophy of the best possible signal path from source to speaker. The JK Series
consists of the JK1 Single Channel DI, JK2 Stereo DI, JKA Single Channel Acoustic DI with Resonance Notch
Filter and the JKP Single Channel Passive DI and Mic Splitter. Also included in the range is the JKT Tone
Generator, a useful solution-provider audio tool that will assist every engineer in the tuning and checking
of systems and components.
KV2’s JK series represents the pinnacle in DI technology, by oering a higher headroom and lower output
impedance, than any other DI on the market. This simply means the JK Series can deliver crystal clear,
distortion free audio from the hottest sources, without a hint of signal degradation over greater distance.
KV2 has optimized the use of phantom power with a special switching power supply on the JK Series, to
enable an impressive 20 volts of peak power on the internal rails. This allows the JK Series to deliver 50
Ohms on the XLR output giving true line driver capability delivering greater audio integrity and the ability
to send high quality signal four times the distance of it’s nearest competitor.
All JK Series DI boxes are hand built in the Czech Republic utilizing high quality components and
transformers. Full transformer balancing ensures the highest possible signal integrity without interference
from RF or ground loops. The heavy-duty steel enclosure provides maximum protection for the electronics
and further shielding against external interference. KV2 stands by the build quality of these units with a full
5-year warranty.
JK1 - Active DI BOX - Line Driver
The JK1 features two 1/4” jack inputs with mix or parallel function with a variable low cut lter and 15dB
pad. Phase Shift and Ground Lift switches are also available. The JK1 is ideal for connection of single
keyboards, guitars or instrument amplier output conditioning or combining two inputs via the mix
function.
JK-series
JK2 - Stereo DI BOX - Line Driver
The JK2 features two 1/4” jack inputs with parallel monitor outputs as well as RCA inputs. The JK2 has two
completely separate channels and can be used with two dierent instruments or stereo instruments. The
JK2 features a variable Pad, Phase Shift and ground lift.
JKA - Acoustic DI BOX - Line Driver
The JKA is a dedicated DI for acoustic instruments. The JKA features a high-impedance 1/4” jack input
capable of receiving signal from all types of pick-ups. A +10dB gain boost is available for low-level
instruments. The JKA also features a tunable notch lter for eliminating the resonant frequency in an
acoustic instrument, reducing feedback issues.
JKP - Passive DI BOX - Transformer Balanced
Serves as a universal passive DI box with low output impedance. The JKP features one XLR input and two
1/4” jack inputs in parallel. The JKP is dedicated for multiple instruments connection such as keyboards,
guitars or instrument ampliers output conditioning. The JKP also features phantom power supply
transmission for condenser microphone connection and output signal conditioning.
JKT - Tone Generator
The JKT is the perfect tool for checking and tuning PA systems along with various pieces of equipment.
Phantom powered it has two XLR Outputs and 1/4” Jack Out.
The JKT delivers a full range of tones from 20Hz through to 30kHz, as well as both White Noise and Pink
Noise.
Overview
3
JK1 - Active DI BOX - Line Driver
JK1 - Active DI BOX - Line Driver
The JK1 features two 1/4” jack inputs with mix or parallel function with a variable
low cut lter and 15dB pad. Phase shift and ground lift switches are also available.
The JK1 is ideal for connection of single keyboards, guitars and instrument
amplier output conditioning or combining two inputs via the mix function.
1. Phantom Power Supply
For ease of use, maximum headroom and low noise the JK1 is powered by
phantom power from the mixing console. A green LED indicates the presence of
JK1
MADE IN CZECH REPUBLIC
JK1, ACTIVE DI BOX
Product number:
KVV 987 205
3. Low Cut Switch
Selects the high pass lter frequency point between 160 and 80Hz.
Ideal for eliminating unwanted bass rumble from instruments.
4. Low Impedance Output
The main symmetrical LINE OUT output has an impedance of 50Ω
and it is Intended for connection to a mixing desk. The output is
separated galvanically from the input.
5. PHASE Switch Selector
Selects between 0° and 180° for LINE OUT output. This switches the
XLR pin-2 and pin-3 to interface with older equipment. Also can be
used when the instrument is being reproduced by the DI and
microphone to avoid cancellation.
6. GND Ground Switch Selector
This ground-lift switch breaks the ground between the input & the
output to eliminate hum and noise caused by ground loops.
The GND position - the grounds for the input and output are
interconnected ideal if the signal source is not grounded.
The LIFT position - the grounds for the input and the output are
disconnected. It is used if the signal source is grounded and you are
experiencing ground loop problems.
phantom power. Simply switch on phantom power on your console and you are
good to go.
2. Input Selection Switch
The JK1 features two asymmetrical inputs with 1/4“ jack connectors. These inputs
can be set as a parallel (input is present on thru), mixed together (inputs placed
into the input and thru are mixed together) or parallel with -15dB attenuation on
input.
OFF
80Hz
160HzLIFT
JK1 - FRONT PANEL
1
4
LINE OUT 50Ω
PHANTOM IN
JK1 - REAR PANEL
2263
PARALLEL
-15dB
GND
MIX
PARALLEL
5
PHASE
0º
180º
Features
THRU
JACK 1/4
INPUT
JACK 1/4
4
PARRALLEL
MIX
PARRALLEL
-15dB
INPUT
SETTING
LOW CUT
20Hz
80Hz
LOW CUT
160Hz
JK1 Block diagram
GND
DC
DC
convertor
ON
PHASE
2
1
3
LINE OUT
PHANTOM
POWERED
LOW Z 50Ω
JK1 Connection
JK1 - SPECIFICATIONS
System Acoustic PerfomanceFeatures
-1dB Response20Hz ÷ 100kHzGain0 / -15dB
Dynamic Range>130dBPhase0° / 180°
Total Harmonic Distortion<0.002%High Pass Filter20, 80, 160Hz
The JK2 features two 1/4” jack inputs with parallel monitor outputs as well as RCA
inputs The JK2 has two completely separate channels and can be used with two
dierent instruments or stereo instruments. The JK2 features a variable pad,
phase shift and ground lift.
1. Phantom Power Supply
For ease of use, maximum headroom and low noise the JK2 is powered by
phantom power from the mixing console. A green LED indicates the presence of
JK2
MADE IN CZECH REPUBLIC
JK2, STEREO DI BOX
Product number:
KVV 987 217
3. GAIN Switch
Using the GAIN switch selector the input sensitivity of the JK2 can be adapted at three levels: 0dB, -12dB,
-24dB, so very high-level inputs can be suitably reduced for clear,
distortion-free reproduction.
4. XLR 50ohm Outputs
The JK2 includes two LINE OUT outputs with XLR connectors. Outputs
work with an impedance of 50Ω and it is intended for connection to a
mixing desk. The outputs are separated galvanically from the input.
5. PHASE Switch Selector
Selects between 0° and 180° for LINE OUT output. This switches the
XLR pin-2 and pin-3 to interface with older equipment. Also can be
used when the instrument is being reproduced by the DI and
microphone to avoid cancellation.
6. GND Ground Switch Selector
This ground-lift switch breaks the ground between the input & the
output to eliminate hum and noise caused by ground loops.
The GND position - the grounds for the input and output are
interconnected ideal if the signal source is not grounded.
The LIFT position - the grounds for the input and the output are
disconnected. It is used if the signal source is grounded and you are
experiencing ground loop problems.
The RC position - the grounds for the input and the output are
interconnected via a parallel RC combination. It is used to suppress
static disturbance.
Features
INPUT A
JACK 1/4
INPUT A
JACK 1/4
INPUT A
RCA
phantom power. Simply switch on phantom power on your console and you are
good to go. The JK2 can be powered to channel A, channel B or both outputs,
which provides best results.
2. Multiple Inputs
Each channel features two paralleled inputs (A, B) each equipped
with 1/4“ jack connectors and stereo RCA inputs on the rear of the unit.
3553
0dB-12dB -24dB0dB-12dB -24dB0°
62
INPUT AINPUT B
JK2 - FRONT PANEL
1
LINE OUT B
1
4
LINE OUT A
JK2 - REAR PANEL
LINE OUT A
2
3
PHANTOM POWERED
1
LOW Z 50Ω
-24dB
0dB
GAIN
- 12dB
PHASE
DC
DC
convertor
ON
2
4
INPUT A
INPUT B
INPUT B
JACK 1/4
INPUT B
JACK 1/4
INPUT B
PHASE
-12dB
-24dB
0dB
GAIN
RCA
JK2 Block diagram
RC
LIFT
GND
GND
LINE OUT B
2
3
PHANTOM POWERED
1
LOW Z 50Ω
6
JK2 Connection
JK2 - SPECIFICATIONS
System Acoustic PerfomanceFeatures
-1dB Response10Hz ÷ 40kHzGain Pad0 / -12 / -24dB
Dynamic Range>120dBPhase0° / 180°
Total Harmonic Distortion<0.005%IndicatorsPower-ON LED
Ground ModeGND / Lift / RC
Signal InputPower
Input Channels2x 1/4" Jack + 2x RCAPhantom Power48÷56V / 8mA
Input Impedance2x 1MΩ / 10KΩ
Max. Input voltage1V / 5V / 20V peak
Signal OutputPhysical Dimensions
Output channels2x XLR, 2x 1/4" Jack THRUHeight40mm (1.57")
Output Impedance50ΩWidth80mm (3.15")
Depth131mm (5.16")
Weight630g (1.39lbs)
JK2 - STEREO INSTRUMENT SETUP EXAMPLE
STEREO INSTRUMENT
0dB-12dB-24dB0dB-12dB-24dB0°
JK2
ON STAGE STEREO
INSTRUMENT AMPLIFIER
MIXING CONSOLE
JK2 - STEREO PLAYER SETUP EXAMPLE
MIXING CONSOLE
INPUT AINPUT B
JK2 - FRONT PANEL
LINE OUT B
JK2 - REAR PANEL
0dB-12dB-24dB0dB-12dB-24dB0°
INPUT AINPUT B
JK2 - FRONT PANEL
LINE OUT B
JK2 - REAR PANEL
LINE OUT A
LINE OUT A
INPUT A
INPUT B
Connection
INPUT A
INPUT B
STEREO PLAYER
7
JKA - Acoustic DI BOX - Line Driver
JKA - Acoustic DI BOX - Line Driver
The JKA is a dedicated DI for acoustic instruments. The JKA features a
high-impedance 1/4” jack input capable of receiving signal from all types of pick-ups.
A +10dB gain boost is available for low-level instruments. The JKA also features a
tunable notch lter for eliminating the resonant frequency in an acoustic instrument,
reducing feedback issues.
1. Phantom Power Supply
For ease of use, maximum headroom and low noise the, JK1 is powered by phantom
JKA
MADE IN CZECH REPUBLIC
JKA, ACOUSTIC DI BOX
Product number:
KVV 987 204
3. Line Out XLR Output
The main symmetrical LINE OUT output works with an impedance of 50Ω
and it is intended for connection to a mixing desk. The output is not
separated galvanically from the input.
4. Monitor Out 1/4“ Jack Output
The adjacent symmetrical MONITOR OUT 1/4“ jack output has an
impedance of 100Ω, the same level as LINE OUT and it is separated from
the main output using a transformer. When using a mono jack the relevant
input is switched automatically to the asymmetrical mode. It can be used
for monitoring on the stage.
5. Tunable NOTCH Filter
To eliminate the dominant self-resonance, (feedback) of any acoustic
instrument, the JKA is equipped with a phase switch selector and a tunable
NOTCH lter with a switchable attenuation level of - 6dB and -12dB.
Recommended method of adjustment for the NOTCH lter:
a) Increase the amplication until the acoustic instrument feeds back
b) Suppress the acoustic feedback at low frequencies using the PHASE
switch
c) Increase the amplication until the acoustic instrument feeds back
again, put the NOTCH switch selector to the - 6dB position and eliminate
the feedback by use of the potentiometer. If the acoustic feedback
continues to happen at the same frequency put the NOTCH switch
selector in the -12dB position.
power from the mixing console. A green LED indicates the presence of phantom
power. Simply switch on phantom power on your console and you are good to go.
2. High Impedance Input
The JKA includes one 1/4“ high impedance jack input. It is adapted to connect the
pick-up of acoustic instruments that require high load impedance (e.g. Piezo electric
pick-ups). By using the GAIN selector switch, the amplication of the JKA can be
increased by +10dB.
FREQ
NOTCH
JKA - FRONT PANEL
4
MONITOR OUT
JKA - REAR PANEL
1
LINE OUT
65
2
GAIN
PHASE
2
3
INPUT
6. PHASE Switch Selector
Features
Selects between 0° and 180° for LINE OUT output. This switches the XLR pin-2 and pin-3 to interface with
older equipment. Also can be used when the instrument is being reproduced by the DI and microphone to
avoid cancellation.
INPUT
JACK 1/4
0dB
+10dB
GAIN
-12dB
NOTCH FILTER
NOTCHFREQ
0dB
- 6dB
PHASE
ON
LINE OUT
2
3
PHANTOM POWERED
1
LOW Z 50Ω
MONITOR OUT
600Ω
JKA Block diagram
8
JKA Connection
JKA - SPECIFICATIONS
System Acoustic PerfomanceFeatures
-1dB Response10Hz ÷ 40kHzGain0/ +10dB
Dynamic Range>130dBPhase0° / 180°
Total Harmonic Distortion<0.03%IndicatorsPower-ON LED
The JKP is a universal passive DI box with low output impedance. The JKP features
one XLR input and two 1/4” jack inputs in parallel. The JKP is dedicated for multiple
instruments connection such as keyboards, guitars or instrument ampliers
output conditioning. The JKP also features phantom power supply transmission
for condenser microphone connection and output signal conditioning.
1. Phantom Power Through
MICROPHONE
SPLITTER
JKP
MADE IN CZECH REPUBLIC
JKP, PASSIVE DI BOX
Product number:
KVV 987 201
3. XLR and Jack Inputs
The JKP features two inputs with the XLR and 1/4” jack connector
connected in parallel. Both outputs are connected symmetrically.
When using a mono jack, the relevant input is switched automatically
into the asymmetrical mode. To split a microphone signal to dierent
sources simply plug it into the XLR input. The JKP has the ability to
send high quality microphone signal long distances (Up to 300m).
4. RATIO Switch Selector 1:2 / 1:4
This is intended for changing the voltage and impedance ratio. For
example, a condenser microphone's impedance can be decreased 16
times (1:4 position) which will improve the sound quality and
capability of the microphone to drive long cables. The 1:2 position can
also be used to improve the sound quality on dynamic microphones.
Both inputs can be disconnected from the ground. The 1:4 ratio is for
use with high impedance sources and the 1:2 ratio is for lower
impedance sources.
5. GND Ground Switch Selectors
This ground-lift switch breaks the ground between the input & the
output to eliminate hum and noise caused by ground loops.
The GND position - the grounds for the input and output are
interconnected. It is used if the signal source is not grounded.
The LIFT position - the grounds for the input and the output are disconnected.
Features
It is used if the signal source is grounded. Interruption of the ground loop.
The RC position - the grounds for the input and the output are interconnected via a parallel RC combination.
It is used to suppress static disturbance.
PARALLEL INPUT
JACK 1/4
INPUT
XLR / JACK 1/4
COMBINED
The JKP DOES NOT REQUIRE PHANTOM POWER TO OPERATE. When using a
condenser microphone that requires a phantom power from the mixing desk, turn
the PHANTOM THROUGH switch selector to the ON position and the RATIO switch
selector to the 1:4 position, (so that both switch selectors are in the top position).
In position 1:2, no phantom power will be passed through the unit to the
microphone.
2. Monitor and Line Outputs
The symmetrical LINE OUT output works with an impedance of 100Ω and with a
ratio of 1:2 or 1:4. The adjacent MONITOR OUT output has an output impedance of
600Ω and a level 6dB higher than the LINE OUT output. The ratio of the monitor
output is half that of the line output. (1:2 LINE = 1:1 MONITOR OUTPUT)
3341
PHANTOM
THROUGH
PARALLEL INPUT
JKP - FRONT PANEL
5 522
MONITOR OUT
GND
GND
LIFT
RC
JKP - REAR PANEL
1
3
2
PHANTOM THROUGH
RATIO
1:2
1:4
2
LINE OUT
3
1
LOW Z, 100Ω
GND
RC
LIFT
GND
RC
LIFT
LINE OUT
10
JKP Block diagram
GND
2
3
1
MONITOR OUT
600Ω
JKP Connection
JKP - SPECIFICATIONS
System Acoustic PerfomanceFeatures
-1dB Response20Hz ÷ 30kHzGainRation 1:2 / 1:4
Total Harmonic Distortion<0.0005%Ground ModeGND, Lift, RC
Signal InputPower
Input Channels1/4" Jack, XLR// 1/4" JackPhantom PowerPhantom through
The JKT is the perfect tool for checking and tuning PA systems along with various
pieces of equipment. Phantom powered it has two XLR Outputs and ¼” Jack Out.
The JKT delivers a full range of tones from 20Hz through to 30kHz, as well as both
White Noise and Pink Noise.
1. Phantom Power Supply
For ease of use, the JKT is powered by phantom power from the mixing console.
Phantom power supply presence is indicated by a single green LED.
JKT
MADE IN CZECH REPUBLIC
JKT, TONE GENERATOR
Product number:
KVV 987 272
4. Frequency Selector
Sets the frequency range of the continuous frequency selector of the
sine wave generator in ranges (20Hz ÷ 300Hz), (200Hz ÷ 3kHz) and
(2kHz ÷ 30kHz).
5. Output Level
Sets the output level of selectable generators.
2. Multiple Outputs
The symmetrical LINE OUT output works with an impedance of 50Ω, and is
intended to be connected to a mixing console or any phantom power source
device. The adjacent MONITOR OUT output has an output impedance of 600Ω
and paralleled 1/4” jack connector output.
3. Generator Selector
The JKT features a sine wave, tone
generator with a frequency range from
20Hz to 30kHz, pink and white noise
generator.
JKT - TONE GENERATOR, PA TUNING & EQUIPMENT TESTING
JKT - FRONT PANEL
FREQ
120
100
150
60
180
30
280
300
20
LEVEL
Height40mm (1.57")
Weight630g (1.39lbs)
7
9
JKT
INSTRUMENT AMPLIFIER
TEST
ACTIVE SPEAKER
CHECK
OUTPUT
MIXING CONSOLE
JKT - REAR PANEL
OUTPUT
PHANTOM IN
PA SYSTEM
Connection
13
Warranty
WARRANTY
Your JK DI BOX is covered against defects in material and workmanship. Refer to your supplier for more
details.
SERVICE
In the unlikely event that your JK DI BOX develops a problem, it must be returned to an authorized
distributor , service centre or shipped directly to our factory. Because of the complexity of the design all
repairs must be attempted only by qualied technical personnel.
If the unit needs to be shipped back to the factory, it must be sent in its original carton. If improperly packed,
JK-DI
the unit may be damaged. To obtain service, contact your nearest KV2 Audio Service Centre, Distributor or
Dealer .
Warranty
14
The future of sound.
Made perfectly clear.
At KV2 Audio our vision is to constantly develop
technologies that eliminate distortion and
loss of information providing a true dynamic
representation of the source.
Our aim is to create audio products that absorb
you, place you within the performance and deliver
a listening experience beyond expectation.