Robert koda Takumi K-15 EX User manual

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RCE
VOLUME
TakumiSeries
EX
EX
TAKUMI K -AMPLIFIER
Takumi K-15 Owner's guide

Thank you
We extend our hand in deep gratitude, thanking you for selecting the Takumi K-15 EX pre-amplifier.
This pre-amplifier is easy to install and use but there are some precautions that need to be observed
in order to attain maximum performance, safety and reliability. Please therefore read carefully thru
this owner’ s manual before installing your K-15.
If there any doubts in your mind or should you require any supplementary information, please do not
hesitate to contact your distributor or Robert Koda directly.
Cordially,
Robert Koch.
Copyright Work
All information, text and art work in this manual is the sole property of Robert Koda LLC.
Any reproduction in whole or in part, may not be reproduced either mechanically or electronically
without the expressed and written permission of Robert Koda.
Important safety information
This unit is designed to be earthed.
Please therefore ensure that the AC power cable you select to use with the K-15 is a three wire type
that is earthed. Failure to do so may render a potentially dangerous situation.
There are no user serviceable parts inside. Please therefore do not attempt to open, adjust or modify
this pre-amplifier.
Power up and power down sequence.
Due to the fact that the K-15 does not incorporate power up / down muting circuits, a pulse may be
emitted from the speakers if the pre-amplifier is not powered up or down in the correct sequence. We
recommend the good audio practice of -
On power up, turn the pre-amplifier on twenty seconds or more before the power amplifier(s).
On power down, turn off the power amplifiers before turning off the pre-amplifier.
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Takumi K-15 EX Owner's guide

Placement requirements
Owing to its substantial weight, this pre-amplifier should be placed on a firm, stable and solid surface.
The use of a dedicated audio stand or plinth may provide some degree of increased performance.
Areas of high humidity, direct sunlight, exposure to flammable gas or possible exposure to liquids are
not suitable locations.
This pre-amplifier is not designed to stand directly on top of other audio components or have other
audio components placed on top of it.
Connections
Inputs - Source 1-5
Any source component, balanced or unbalanced may be connected to input 1 to 5.
K-15 offers a high input impedance of 50K ohm per signal phase. Also, due to the structure of the
volume control and this pre-amplifier, “overload” is essentially impossible.
When using the RCA (SE inputs) please insert a shorting pin between pins 1 and 3 on the corresponding
input numbers XLR socket. If your source component offers both balanced and unbalanced outputs it
may be worthwhile to compare them to determine which one sounds best in your system.
Outputs
Two pairs of RCA’s and two pairs XLR’s are available for output connection. When the Balanced / SE
switch is set to SE, all four outputs function in the single ended mode. With pin 2 on the XLR being “hot”
and pin 3 being “zero”.
When the Balanced / SE switch is placed in the Balanced setting, the XLR sockets provide a true
balanced output with pin 2 being “hot” and pin 3 being “cold”.
The K-15 has a low output impedance and can deliver very high signal levels if need be. Thus long
cables and “difficult” power amplifiers pose no problem.
A Note on the RCA sockets
Great care should be taken, especially with cables that fit too tight or use locking systems as they may
damage the RCA sockets on the back of the pre-amplifier when the plug is inserted or removed.
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AC Inlet
The AC voltage selector and fuses are integrated into the IEC AC inlet socket. Looking at the “window”
one can read the voltage setting.
This pre-amplifier may be set to either a 230V or 115V “design centre”.
Please ensure that the pre-amplifier is set correctly before connecting to your AC power source.
The 230V design centrer will work over a range of 200 to 255V while the 115V design centre will work
over a range of 100 to 128V.
Fuses
A pair of five by twenty mm, 250V fuses are installed into the fuse drawer. The fuses may be replaced
by disconnecting the unit from the mains and then opening the drawer with a suitable tool. Use 1A
fuses for 230V and 2A fuses for 115V.
Ground terminal and switch
To aid system fine tuning, a chunky ground terminal is provided.
This terminal connects internally to the K-15’s audio signal zero volt reference.
When the ground switch is placed into the “lift” position, the signal zero voltage reference is somewhat
“decoupled” from the chassis ground path. Setting the switch onto “lift” may assist in ridding some
system combinations of “earth loops”.
Front panel description
Ruby power indicator
This indicator becomes illuminated when the power is on.
It takes a few seconds to reach full illumination level.
Power knob.
The power knob is designed to require some “initiative” to turn it. It is a 90 degree rotary switch. To
turn on, rotate 90 degrees clockwise. To switch off, rotate 90 degrees counter clockwise. There is no
“stand-by” mode. The pre-amp is either on or off.
Volume control
This control is designed to be advanced much further than is typical with most pre-amplifiers.
Starting at the 12 O'clock position is a good starting point unless you have high efficiency speakers in
which case the volume may be set to a lower setting.
The markings indicate the actual “throughput” gain with the maximum being +8dB(V).
Input selector
Use this to select the required input 1 thru 5. This is a full mechanical selector of the highest quality.
The “feel” of each control, volume and power is consequently different.
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Takumi K-15 EX Owner's guide

General use
Burn in time
If your K-15 has not been used for some months, relocated or is brand new, it might require two or
three days of power on state to “bed in the components”. Such may be done by simply leaving the
pre-amplifier on for a couple of days. It is not specifically required for the K-15 to be passing thru a
music signal during this process.
Ambient temperature
This pre-amplifier is set up for an average room temperature. If the room temperature is very cold we
recommend allowing the room to warm up before powering up the K-15.
Locating the K-15 too on top of a heat generator such as a hot power amplifier may also reduce the
pre-amplifiers performance.
Warm up time
Upon power up the K-15 will become functional after about twenty seconds or so. After a further twenty
minuets, optimal sound quality will become available.
Please note: The K-15 is not designed to be left on permanently. Please turn it off when there is no
intended use for some time.
Cleaning and maintenance
The K-15 may be dusted down with a soft cloth. A cloth dampened in a mild solution of soap and warm
water may be effective at removing grease.
If you live in a corrosive environment it may be worthwhile to keep the K-15 covered with a large cloth
when not in use. To keep the K-15 looking brand new it may also be beneficial to guard any un-used
input and output sockets with a suitable masking tape or similar.
Servicing
Servicing should only be undertaken when there is a fault condition within the pre-amplifier. Please
contact your distributor or alternatively Robert Koda for advice and we will provide prompt assistance.
There are no user serviceable parts inside this pre-amplifier.
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Technical specifications
Specifications subject to change without notice.
Weight
Dimensions
Input impedance
Output impedance
Input equivalent noise
Typical mid-band distortion
Voltage gain
Frequency response
Power consumption
27Kg unpacked.
169mm high with feet installed, 380mm wide and
380mm deep excluding knob and socket protrusions.
50K Ohm (Single ended), 2X 50K ohm Balanced
2X37 ohm balanced, 1X 75 ohm single ended.
1.8 micro volts A weighted.
Less than 0.0005% driving 1K ohm load at 4V RMS
Plus 8 dB
Less than 3Hz to greater than 110 KHz, minus 3dB
Thirty watts.
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Takumi K-15 EX Owner's guide

The meaning of "Takumi"
The meaning of the Japanese character “Takumi”
can be translated as “Maestro”.
Our brand endeavours to build a product in the
spirit of Maestro.
392-1 Okawa Higashi-Izu
Shizuoka Prefecture
413-0301 Japan
Robert-Koda LLC