FAQGeneral questions General technical questions TX-1A TX-2A TX-3A CX-1A & CX-1B CX-2A CX-3A MF-15A DH-18 KW-18
Why does the KW-18 amplifier use 3 Powercon connectors?
The KW-18 provides 3 x 20 Ampere Neutrik PowerCON Connectors to power the KW-18 amplifier. To ensure the full output power capability, the amplifier needs to run with all 3 connectors connected and powered using 16A Type "C" Circuit Breakers. In the case of lower power use it could be operated however using only two of the Neutrik Powercon connectors and as such, powered from only 2x 16A Type "C" Circuit Breakers.
The Unit can not start when only one of the Powercon connectors is used! The KW-18 can only work from voltages of 90V AC – 255V AC 50-60Hz! Operation from DC Voltage is not possible!
What is the pinout of the 4 x SpeakON connectors of the KW-18?
The KW-18 provides 4 x Neutrik SpeakON NL4 type Connectors to power the corresponding loudspeakers. All 4 connectors use +1 as „+“ and -1 as „-“ output for the corresponding channel. +2 and -2 pins are not used! The Loudspeaker connectors used on KW-18 are fully compatible with both Neutrik Speakon NL4 and NL2 type plugs!
Can I use the KW-18 with 110V ac power line?
In the case of 110V power line we strongly recommend the use of „Delta” circuit – meaning, that each Neutrik PowerCON Connector carries two Phase and one PE line (in this special case Neutral Line is not used!). This would give 190V effective AC for all of the three Power Inputs on the KW-18. For this operation we recommend 20A Type „C” Circuit Breakers! Using the KW-18 from single, two or three phase 110Vac Line(s) with 20A Type „C” Circuit Breakers could limit the maximum achievable output power!
The unit must be grounded to the PE of the Power Network thru all three Power connectors! In the case of an Off-Grid use (for example using a Power Generator), a proper grounding network must be provided to the PE pins of the Power input connectors of the unit!
PE impedance should be always kept low! The use of a GFCI unit is recommended! In the case of single phase power line application, use a common single phase GFCI! In the case of three phase power line application, use a single three-phase GFCI! Special local electrical safety compliance regulation may apply!
What is the voltage gain of the KW-18?
The voltage gain of the KW-18 is 30dB.
What is the input impedance of the KW-18? How many inputs can I use in paralell from a single DSP output?
The symmetrical audio inputs have 10kOhm impedance, when the channel Input Signal Attenuator (Input Level Knob) is at its minimum position (counter-clockwise). The input impedance with the attenuator at its maximum position (clockwise) is 20kOhms.
Usual drive capacity of DSP units on the market is 600 Ohms. Daisy chaining more inputs (and/or more KW-18 units) is limited therefore to 16 inputs altogether (625 Ohms) with the input signal attenuators at their minimum positions. With all attenuators at their maximum position, the number of inputs driven in parallel (daisy chained) could be as high as 32!
What is the minimum load impedance allowed for the KW-18?
The minimum load impedance of the KW-18 is 2 Ohm. In order to use the output power optimally, we recommend using it with loads above 2.66 Ohm (3 pcs. of 8 ohm speakers used in parallel).
What do the frontpanel LEDs mean?
Phase OK LEDs (Green): Lites up when there is power availabe on the corresponding power input and the voltage is in the normal range (90V-255Vac / 50-60Hz)
Fault LED (Red): Lites up when there is a fault in the KW-18 power amplifier unit. In the case of fault please contact Lambda Labs or a local Lambda Labs sales partner!
Limit LED (red): Lites up when either of the following scenarios occour: -Peak voltage limiting -Peak Current limiting -RMS Current limiting
-3dB LED (Yellow): Lites up when the input signal of the channel reaches 3dB below CLIP level
-6dB LED (Green): Lites up when the input signal of the channel reaches 6dB below CLIP level
-12dB LED (Green): Lites up when the input signal of the channel reaches 12dB below CLIP level
Signal present LED (Green): Lites up when the input signal of the channel reaches 50dB below CLIP level
How should I clean the dust filter foam?
Dust filter foam could be saturated and blocked by dust and dirt. In such a case the cooling of the Amplifier will get strongly limited. Therefore regular cleaning of the dust filter is mandatory for proper use! Check the filter foam after every use! If needed, clean it with water!
Reinsert the filter foam only after it is dry! Do not use the amplifier without a dust filter!
Using hazer and/or fog machine fluid can cause a very fast saturation/blockage of the amplifier dust filter foam! In such cases, Lambda Labs recommend checking/cleaning the dust filter on a daily basis!Having reserve dust filter foam is also recommended. Filter foams could be purchased from Lambda Labs directly or from local sales partners.
Why does the KW-18 have rack mounting possibilities also on its rear side?
The KW-18 professional power amplifier can be mounted into a standard 19” Rack case also at the rear side, providing a more stable position. Lambda Labs recommends using both rear and front mounting of the KW-18 in every case! The rear width is 444 mm.
It is of utmost importance to ensure sufficient ventilation for the KW-18 professional amplifier unit! KW-18 uses forced air cooling to ensure safe operating temperature inside the unit. This kind of cooling relies on sufficient fresh air supply. To achieve this, KW-18 has air vents on its front panel, rear panel and on its sides. These air vents should never be covered!
To further increase the cooling effect, Lambda Labs recommends using a blank 1U 19” perforated plate between the KW-18 units, if more KW-18 units are used in a rack!
What kind of cleaning and maintenance should be performed to keep the KW-18 in a good working and optical condition?
Regular maintenance is necessary to keep the amplifier in a good working condition! Dust filter foam could be saturated and blocked by dust and dirt. In such a case the cooling of the Amplifier will get strongly limited. Therefore regular cleaning of the dust filter is mandatory for proper use! Check the filter foam after every use! If needed clean it with water!
Do not remove the top cover (or the rear section) and do not open the KW-18 power amplifier unit! No user serviceable parts inside! Servicing should be always performed by qualified personnel! Always disconnect the KW-18 from power before you perform maintenance!
Reinsert the filter foam only after it is dry! Do not use the amplifier without a dust filter! Do not switch on or even connect to the power the KW-18 until it is not completely dry!