Mackie Big Knob Passive Manual

Big Knob Passive Features

• Excruciatingly simple 2x2 monitor controller
• Choose between two sources and two monitor pairs.
• Classic Big Knob volume control.
• Professional mono, mute and dim functions.
• Pristine audio quality
• Passive audio path with no power supply needed.
• Sturdy "Built-Like-A-Tank" design

Introduction

The Big Knob Passive benefits from a proven, bestselling design to deliver professional level control, plus source and monitor selection for studios of any size.
The passive audio path ensures pristine sonic integrity is maintained throughout your signal chain. More than just a level control solution, Big Knob Passive features the ability to choose between two sources and two monitor pairs.
Ideal for simple level control at a home or project studio or for integration in a large studio or group of editing suites, Big Knob Passive is the "Built-Like-ATank," affordable monitoring control solution.

Quick Start

We realize that you can't wait to hook up your Big Knob Passive and try it out. Nevertheless, please take the time to read this page NOW, and the rest can wait until you're good and ready.

1. Turn down all knobs.
2. Disengage all switches.
3. Plug signal sources into the Big Knob, such as:
   • Audio interface.
   • Line-level sources such as keyboards, drum machines, or MP3 players plugged into the line-level inputs.
   • Other stereo playback devices.
4. Connect cords from the monitor outs to powered speakers (or to an amplifier connected to passive speakers).
5. Turn the powered studio monitors (or amplifiers) on.
6. Be sure that the volume of the input is the same as it would be during normal use.
7. Engage the desired input source select and monitor select switches.
8. Slowly bring up the volume knob to a comfortable listening level.

Hookup Diagram

Big Knob Passive is the perfect monitoring tool as a level control for a home / project studio or integrated as part of a larger studio. There are many great things about the Big Knob Passive, but one of the features is no need for power...it can be placed anywhere to your heart's content! After you've decided on a spot, it's time to make connections.
In this example, a computer installed with your favorite DAW is connected to the Source Input A L/R jacks. The Source Input B jacks may accept 1/4" inputs and an 1/8" stereo input. If both inputs are connected simultaneously, the 1/8" stereo line input will take priority over the 1/4" connection. In this case, we hooked up a smartphone to the 1/8" stereo line input jack.
The output section is as straightforward as the input section. Here we connected a pair of XR Series studio monitors to the Mon Output A L/R jacks and a pair of MRmk3 Series studio monitors to the Mon Output B L/R jacks.
Now that connections have been made, the fun begins! The top panel has a variety of switches, buttons and something else...what was it? Oh yeah, a BIG knob, dead center! These allow you to select between the inputs, outputs, control levels and more. Descriptions of the Big Knob Passive features starts on the next page...

Typical Big Knob Passive Setup

Rear Panel Description

The rear panel is where to connect various sources feeding IN to the Big Knob Passive. These signals are then routed through the Big Knob Passive and released through the monitor OUT jacks.

1. 1/4" Source Inputs
   Connect the L/R line-level signals from the source(s) to the 1/4" source input jack(s).
   • The source input connectors accept balanced or unbalanced signals.
   • Unbalanced TS (tip-sleeve) lines can be accommodated via the TRS jack. Make sure the cable terminates with a TS plug (like a guitar plug), or if it's a TRS plug (such as a headphone plug), make sure the ring is tied to the sleeve and that the plug is fully inserted into the jack.
     The connectors are wired as follows (per the AES/IEC standard):
     Balanced 1/4" TRS

     Hot (+)	Tip
     Cold (–)	Ring
     Shield (Ground)	Sleeve

     
     Unbalanced 1/4" TS

     Hot (+)	Tip
     Cold (–)	Ring
     Shield (Ground)	Sleeve

2. 1/8" Stereo Line Input
   The stereo line input may accept an 1/8" line-level signal from a smartphone, MP3 player, or other signal source.
   
   The Source Input B 1/4" and 1/8" linelevel connections may be connected simultaneously. If both inputs are connected simultaneously, the 1/8" stereo line input will take priority over the 1/4" connection.
3. 1/4" Mon Outputs
   Connect the L/R mon outputs to the inputs of powered studio monitors or to a power amplifier driving passive speakers.
   The mon outputs are fed by the "control room bus." This is the signal path fed from the source input currently selected with the source select button and routed through the volume knob.
   • The mon output connectors accept balanced or unbalanced signals.
   • Unbalanced TS (tip-sleeve) lines can be accommodated via the TRS jack. Make sure the cable terminates with a TS plug (like a guitar plug), or if it's a TRS plug (such as a headphone plug), make sure the ring is tied to the sleeve and that the plug is fully inserted into the jack.
     The connectors are wired per the AES/IEC standard as seen in the illustrations to the left.

7. Mute Switch
   The mute switch does just what it sounds like it does. It turns off the signal by "routing" it into oblivion. Engaging the mute switch (almost) provides the same result as turning the volume knob all the way down.
8. Dim Switch
   Pressing this button turns down the signal going to the monitor outputs by 20 dB. This allows you to essentially "turn down" the speakers to converse without affecting the speaker level.
9. Volume Knob [aka Big Knob]
   Last, but certainly not least, the money maker! The volume knob – aka Big Knob – adjusts the volume of the selected input source's signal going to the selected monitor outputs. The volume knob ranges from OFF (∞) to unity gain (MAX).
   
   Always turn the volume knob all the way down before making connections or trying something new. Keep it down until all changes have been made, then turn it up slowly. This saves your speakers – and more importantly, your ears – from blowing.
   Engage / disengage the switch to select the monitor output. Leave this switch disengaged – up position – to route the currently selected input source to the monitor A output jacks. Press this switch – down position – to route the currently selected input source to the monitor B output jacks.

Service Information

If you think your Big Knob Passive has a problem, please check out the following troubleshooting tips and do your best to confirm the problem. Visit the Support section of our website (www.mackie.com/support) where you will find lots of useful information such as FAQs and documentation. You may find the answer to the problem without having to send your Big Knob Passive away.

Troubleshooting

No Power

• Our favorite question: Is it plugged in? If you answered "yes" to this question, then you're reading the wrong owner's manual. The Big Knob Passive does not get "plugged in"!

No Sound

• Is the signal source turned up? Make sure the signal level from whatever device(s) immediately precedes the Big Knob Passive is high enough to produce sound.
• Is the Big Knob Passive level control turned up?
• Are the source and monitor select switches in their correct positions?
• Is the mute switch engaged?

Bad Sound

• Are the input and output connectors plugged completely into the jacks? Make sure they are plugged all the way in.
• Is it loud and distorted? Reduce the signal level at the source(s).

Noise/Hum/Buzz

• Check the signal cable between the source(s) and the Big Knob Passive. Make sure all connections are secure. These problems usually produce crackling noises, hum, or buzz.
• Make sure the signal cable is not routed near AC cables, power transformers, or other EMI sources (including wall warts and line lumps!). These sources usually produce hum.
• Excessive hiss is an indication of an incorrect gain setting somewhere before the Big Knob Passive.
• If possible, listen to the signal source with headphones plugged in. If it sounds noisy there, it's not the Big Knob Passive.

Repair

Non-warranty service is available at a factory- authorized service center. To locate the nearest service center, visit www.mackie.com, click "Support" and select "Locate a Service Center or Distributor". Service for a Big Knob Passive living outside the United States may be obtained through local dealers or distributors.

If you do not have access to our website, please call our Tech Support department at 1-800-898-3211 (normal business hours, Pacific Time), to explain the problem. They will tell you where the nearest factory-authorized service center is located in your area.

Technical Information

Big Knob Passive Specifications

Big Knob Passive Dimensions

Big Knob Passive Block Diagram

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 a dry cloth.
7. Do not block any ventilation openings. 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. Only use attachments/accessories specified by the manufacturer.
10. Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
    

RISK OF ELECTRIC SHOCK! DO NOT OPEN!

TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE COVER (OR BACK). NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the prescence of uninsulated "dangerous voltage" within the product's enclosure, that may be of significant magnitude to constitute a risk of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user of the prescence of important operating and maintaining (servicing) instructions in the literature accompanying the appliance.

To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.

11. 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 damaged, 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.
12. Exposure to extremely high noise levels may cause permanent hearing loss. Individuals vary considerably in susceptibility to noise-induced hearing loss, but nearly everyone will lose some hearing if exposed to sufficiently intense noise for a period of time. The U.S. Government's Occupational Safety and Health Administration (OSHA) has specified the permissible noise level exposures shown in the following chart.
    According to OSHA, any exposure in excess of these permissible limits could result in some hearing loss. To ensure against potentially dangerous exposure to high sound pressure levels, it is recommended that all persons exposed to equipment capable of producing high sound pressure levels use hearing protectors while the equipment is in operation. Ear plugs or protectors in the ear canals or over the ears must be worn when operating the equipment in order to prevent permanent hearing loss if exposure is in excess of the limits set forth here: