12K72 Stereo and Mono Microphone Preamplifier
Product Information: 12K72 Stereo and Mono Microphone
Preamplifier
The 12K72 is a versatile preamplifier that can be used for both
stereo and mono microphone applications. It is designed to enhance
the sound quality of electric instruments, such as guitars, and can
also be used as a line amplifier when inserted into a stereo mix.
The preamplifier comes with a high impedance increase system that
improves the dynamic response of the instruments connected. The
front panel features jack connectors in female format for mono
inputs, while the rear panel features an unbalanced output (OUT
N.B.) that is taken before the output transformer, giving a subtly
different color from the balanced output.
Important Safety Instructions
Before using the preamplifier, please read the safety
instructions carefully to avoid any accidents or damage.
Power Supply
Refer to the safety instructions on page 3 for information on
how to properly supply power to the preamplifier.
Specifications
The technical specifications of the product are subject to
change without prior notice by the manufacturer.
Warranty
The preamplifier comes with a warranty. Refer to page 8 for more
information.
Notice of Copyright and Ownership
The preamplifier is copyrighted and owned by Kahayan. Refer to
page 10 for more information.
Product Usage Instructions
- Use as a Microphone Preamplifier: Connect a
microphone to the XLR input on the front panel. Turn on phantom
power if needed by flipping the switch on the front panel. Adjust
the gain and output controls to achieve the desired sound
level. - Recording Electric Instruments (electric guitars,
electro-): Connect the instrument to the front panel
instrument input. Adjust the gain and output controls to achieve
the desired sound level. - Use as Line Amplifier Inserted in the Stereo
Mix: Set the input switch in the Line position. The useful
scale becomes that shown in orange and around the gain and output
control. In this position, the phantom power is turned off
automatically. Connect the preamplifier to the stereo mix using the
appropriate cables.
12K72
STEREO AND MONO MICROPHONE PREAMPLIFIER
OPERATOR’S MANUAL
Version 1.3
Avd. de la Estación 4, local bajo Zarzalejo, Madrid 28293 Spain [email protected]
www.kahayan.es
TABLE OF CONTENTS
IMPORTANT SAFETY INSTRUCTIONS…………………………………3 INTRODUCTION……………………………………………………………4 USE AS A MICROPHONE PREAMPLIFIER……………………………..5 RECORDING ELECTRIC INSTRUMENTS ………………………………5 USE AS LINE AMPLIFIER INSERTED IN THE STEREO MIX………….6 POWER SUPPLY…………………………………………………………..7 SPECIFICATIONS & WARRANTY…………………………………………8 RECALL SHEET……………………………………………………………10 CREDITS……………………………………………………………………11
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IMPORTANT SAFETY INSTRUCTIONS
1. Read these instructions 2. Keep these instructions 3. Heed all warnings 4. Follow all instructions 5. Do not use this apparatus near water 6. Clean only with dry cloth 7. Install in accordance with the manufacturer’s instructions 8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat 9. Protect the power cord from being walked on or pinched particularly at plugs and the point where they exit from the apparatus 10. Only use attachments/accessories specified by the manufacturer 11. Unplug this apparatus during lightning storms or when unused for long periods of time 12. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is dam- aged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped
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INTRODUCTION
The 12k72 is a high class preamplifier which contains a `module’ per channel. The main feature of these `modules’ is a sound completely clear and transparent, with deep bass and an extremely natural treble. It its based in on classic 70ies preamp and the components used in manufacturing come essentially from the same manufacturers that supplied the ones used originally, reproducing and expanding the benefits of these. Everything inside this preamplifier is high quality: the wires, rotary switches, capacitors, resistors and connectors. STAGES The 12K72 is formed by two stages, the first gain stage is set with a Gain control, while the second stage remains fixed. The Output control regulates the amount of signal passing from the first stage to the second stage (as a typical fader function). HEATING AND WARM-UP It is advisable to wait a minute after turning it on, to modify the gain and output levels, this way avoiding any noise generated by the lack of capacitor charging. An effect that may damage the reference speakers.
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USE AS A MICROPHONE PREAMPLIFIER
Set the input switch in the Mic position. For proper calibration input gain should be placed to gain control at -20db and the control Output in the position indicated by a small arrow where distortion remains below 0.1%. Then turn up the gain control until the signal has a maximum level, but without audible distortion (which is very evident in your ear when present). Once the Gain is set, if it´s necessary, the Output control can be varied to modify the output signal.
RECORDING ELECTRIC INSTRUMENTS (electric guitars, electro-
acoustic, basses, …) Connect the instrument to the female jacks on the front panel, place the switch in the Mic position (not the Line), set the output key in the position indicated by a small arrow, and adjust the necessary gain. It is important to have the switch in the mic position because in this manner the output will give us a good level without raising too much Gain. The +48V Phantom Power is not present in the front jacks in any possible combination of switches, to prevent damage to the instruments. In the case of connecting electric keyboards or sound modules, it is advisable to place the switch in the Line position due to their high level output.
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USE AS LINE AMPLIFIER INSERTED IN THE STEREO MIX
Set the input switch in the Line position. At this time the useful scale becomes that shown in orange and around the Gain and Output control. In this position the phantom power off automatically. The unbalanced output on the rear (OUT N.B.) is taken before the output transformer which gives a subtly different colour from the balanced output.
Jack connectors-female format found on the front panel, allow us to have mono inputs jack format. When you insert a jack into the front connector it automatically disconnects the corresponding rear canon connector. This system also makes the movement of phantom power to the input jack impossible.
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POWER SUPPLY
The 12K72 has an external power supply that must be connected to the 5 pin XLR founded on the rear of the preamp. NOTE: Don´t forget that the external power supply has an on/off switch:
See Safety Instructions on page 3
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SPECIFICATIONS
· Iron rack format of 1 unit · Two mic / line independent preamp working in pure class A · Using discrete technology (no IC`s) with Carnhill® Transformers · Gain control in steps of 5dB · Output level control by steps of 1dB · 48v phantom power with pilot light · Phase-change switch · Mic / Line Selection Switch · Balanced and unbalanced Input Output (XLR y jack)
· Inputs: Mic Input: 1200, 3 pin XLR bal. Instrument Input: 1M, stereo jack unbal*
*The Instrument input has incorporated a high impedance increase system that obtains a more lineal frecuency response and also improves the dynamic response of the instruments connected.
· Outputs: Balanced: 3 pin XLR
· Unbalanced: Jack Mono. The signal is taken before the output transformer giving another colour to the balanced output
· Max. Gain: XLR input: 65 db
· Output control: Key steps of 12 positions adjustable in 1dB steps (the typical fader function)
· Distorsion: To 22 dbu of output, 40hz less than 0.1%,1Khz less than 0.03% 10 Khz less than 0.05%
· Noise: Less tan -100 dBu
· POWER SUPPLY: 220v. 50hz. 110v. 60hz
· Dimensions (mm): 42 (Height), 435 (Width), 355 (Depth)
The manufacturer reserves the right to change the technical specification of the product without prior notice.
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WARRANTY
These products are guaranteed for a period of two years from the date of shipment to the end user for countries of the European Union. For other countries, please refer to the law in effect. During the warranty period Kahayan Pro-Audio will, at their discretion, either repair or replace products which prove to be defective, provided that the product is returned to an authorised Kahayan service facility. The warranty will not cover shipping the unit back to the Kahayan service facility, unless the customer determines otherwise with his dealer/distributor. Defects caused by unauthorised modifications, accident, negligence or any misuse are not covered by this warranty. For further information please contact your dealer or the distributor in your country.
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NOTICE OF COPYRIGHT AND OWNERSHIP
All designs, circuit board artwork, front panel artwork, text contained herein and therein, and all other intellectual material is the sole property of Pablo Kahayan from Kahayan Audio. Unauthorized use, distribution, reproduction, etc. is strictly prohibited. Kahayan intellectual property is protected by international copyright laws. Violators will be prosecuted to the fullest extent of all applicable laws. Transfer of ownership of this unit neither confers nor implies any transfer of ownership of the intellectual property, proprietary design, etc. contained herein.
CREDITS Concept: Pablo Kahayan Written by: Pablo Kahayan and Luis del Toro Edited by: Luis del Toro and Pablo Kahayan Additional editing: José Ángel Photos and Recall sheet: José Ángel
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Kahayan Pro-Audio
