Table of Contents

Table of Contents i

Section 1 - Introduction and General Information 1

Section 2 - Warranty 2

Section 3 - Specifications 3

Section 4 - Installation 4

Section 5 - Telephone Inputs and "Mix Minus" 12

Section 1 - Introduction and General Information

1.1 Blue 5c Audio Console

Congratulations on choosing an LPB Blue 5c audio mixing console. Blue has combined the operational features of an ON AIR board with mobility and quick installation needed in both editing and remote operations. The small size and low cost also are something new to the market.

Blue is intended for use in both professional and non- professional broadcast applications, including radio, audio production, remotes, standard and low-power broadcast television as well as cable television. Its flexible features, simplicity and excellent specifications extend its potential into allied fields, such as small sound reinforcement systems and recording studios. Blue is an ideal choice in any application requiring superior audio performance, rugged, long-term reliability, ease of maintenance and simple, straightforward operation.

1.2 Console Configuration

Blue is a simple five channel console with stereo linear faders. Each of the five faders has two stereo inputs. Input 1 & 2 for channel one, input 3 & 4 for channel two and so on. Input audio is inserted into the console through RJ45 connectors located on the rear of the unit. There are ten positions respective to inputs 1 through 10 and two stereo output connections for Program and Cue. The DB25 pin connector located on the rear panel provides contact points for remote start tally’s for all 10 inputs, Send bus audio, Program and Cue metering, On Air light tally as well as +/- 15VDC and Ground. A 10 position DIP switch is located on the rear panel. When a switch is enable, the respective ON switch, when depressed, will actuate the ON AIR Light tally on the DB25 and the console ON AIR symbol will light as well. Studio monitor audio feeds are provided on the rear panel by two balanced ¼ " phone jacks. Level control is provided by a fader control located on the right side of the console. Two separate headphone jacks and controls are located on both the left and right front corners of the unit on ¼ " phone jacks. A switch selecting either Program of Cue as well as a level pot are provided.

FOR DETAILED CONNECTOR INFORMATION SEE THE

INSTRUCTION LABEL LOCATED ON THE BOTTOM OF THE CONSOLE

Section 2 - Warranty

Blue 5c Warranty Information

LPB Communications warrants its Blue 5c Audio Mixing Consoles to be free of defects in materials and workmanship for a period of 2 years from date of original shipment and excludes wear items such as indicators, fuses, etc. Assemblies obtained by LPB Communications from other manufacturers for use in Blue, such as faders and switches, carry a warranty only as stated by the original manufacturer, typically one (1) year, and LPB Communications assumes no other liability. LPB Communications assumes no liability for damage to product incurred in shipment or handling.

To establish the validity of the warranty, warranty registration forms included with the product at time of shipment must be completed and submitted to LPB Communications at time of receipt by the original purchaser. Failure to do so may invalidate any or all portions of the warranty.

The warranty is limited to malfunctions or defects discovered in the course of normal and correct usage and/or maintenance of the product. Damages due to abuse, user misalignment, lack of proper maintenance, usage or maintenance outside that prescribed in the Service Manual for the product, mains voltage fluctuations or excursions, exposure to the elements, or acts of God, are not covered under this warranty. Modification or alteration of the product by any party other than LPB Communications causes this warranty to be null and void.

Warranty claims will be honored only through the established procedures of LPB Communications. Product may be returned only following written notification to LPB Communications within thirty days of the discovery of a malfunction or defect, and then only by utilizing LPB Communications Material Return Authorization (MRA) system and procedures. LPB Communications reserves the right, at its option, to repair, replace, or refund the original purchase price of defective product. LPB Communications assumes no liability for shipping, handling, insurance, duty, or tariff fees incurred in connection with the support of this warranty.

The full extent of the purchaser rights and remedies are stated above. No other warranties expressed or implied by any third party is binding on LPB Communications. LPB Communications assumes no liability for incidental or consequential damages arising from the use, or inability of use, of this product.

Section 3 - Specifications

Input:

Input Impedance:

Line 10,000 ohm bridging

Levels:

Line, 0 dbm

Output:

Program

Transformer Isolated, 600 ohm, +4dbm

Cue & Send

Active Balanced, 10,000 ohm, .775V rms

Frequency Response:

Line, 20 - 20 kHz ± 0.5 db

Noise:

Line, better than -80 db

Crosstalk/Muting:

Better than 70 db between any outputs @ 1 kHz

Harmonic Distortion:

Less than 0.03% THD, 20 - 20 kHz

Intermodulation Distortion:

Less than 0.03% SMPTE

AC Line Input

100/120/220/240 VAC, 47-63 Hz

Physical Characteristics:

Height: 3.5"

Depth: 12.5"

Width: 16.5"

Weight: 5.25 lbs.

Section 4 - Installation

4.1 Unpacking

BEFORE UNPACKING, INSPECT THE SHIPPING CONTAINER FOR ANY EXTERNAL EVIDENCE OF SHIPPING DAMAGE. Document any external damage in writing, and/or photograph it before opening the carton. If the damage is extensive, notify the carrier before opening.

SAVE THE CARTONS AND ALL PACKING MATERIAL UNTIL THE EQUIPMENT IS COMPLETELY INSTALLED AND OPERATING SATISFACTORILY. If hidden shipping damage is found upon opening the cartons, notify the carrier and LPB Communication at once. The carrier will want to inspect the shipping carton and packing materials. Federal regulations require that freight claims be filed by the recipient of the shipment; failure to file a claim with the shipper in a timely manner may result in a claim denial.

4.2 Inspection

If you ordered any optional items, such as the B series of cables, make sure they are present. Contact the LPB Customer Service Department if any discrepancies are found. This is a good time to complete and return your Warranty Registration Form.

4.3 Grounding Information

Proper grounding is the most critical part of any console installation. In addition to being electrically hazardous, improper grounding can severely degrade the operation of the console and the entire studio. DO NOT PROCEED WITH INSTALLATION UNTIL YOU HAVE A GROUNDING PLAN THAT SATISFIES THE REQUIREMENTS OF YOUR LOCAL ELECTRICAL CODES AND ACCEPTABLE AUDIO PRACTICES. If you are not experienced in designing grounding systems for audio studios, consult with an experienced professional.

The goal of any audio grounding system is to provide proper grounding for all equipment while avoiding ground loops. A ground loop is present any time a piece of equipment has two or more paths to ground (See Figure 4.1). For example, if a tape machine is connected to ground through the grounding prong of the AC line cord and by the shield connections of its audio lines, a ground loop exists.

Figure 4.1

Ground loops often cause noise in the system, usually in the form of 60 or 120 Hz hum or buzz, and may induce RF interference. To eliminate a ground loop, all paths to ground must be severed, except one (preferably the AC safety ground). NOTE: AUDIO SHIELDS DO NOT PROVIDE AN ACCEPTABLE AC SAFETY GROUND. Clipping off the grounding prong on the AC plug, or using a 2-prong plug adapter, and grounding the machine by way of its audio shields only, is extremely unsafe, with potentially lethal consequences.

It is standard practice to ground all input shields at the console end of the line, and leave the shield disconnected at the source equipment end. Console output shields are normally left open at the console end, and grounded at the load end. The AC safety (chassis) grounds of all external equipment (as well as the console's) should be returned to the same physical and electrical point in the studio for optimum operation. In areas of intense RF interference, shields with one end un-terminated may pick up RF and radiate it into the console. In this case, the open end of the shield should be connected to ground with a small 0.1 ufd capacitor (see Figure 4.2); the capacitor will act as a short to RF frequencies, but will appear as an open circuit at 60 and 120 Hz.

Special care should be taken when integrating equipment with unbalanced (consumer) inputs and outputs into the system. Much of this equipment has no provisions for chassis grounding at all. In this case, one audio cable shield must be terminated at both ends, or the audio circuit will not work for lack of a ground reference. Unbalanced equipment with a grounded chassis (such as some professional power amplifiers) should be installed normally, i.e., with shields open at the console end, and the chassis returned to ground by a grounding cable. Alternatively, an isolation transformer may be used at the input of the unbalanced device.

Some devices feature a ground link or jumper for strapping the chassis ground to the audio ground. Be sure these links are connected in accordance with your grounding plan.

The console and all external equipment are usually grounded to a grounding bus of copper strap by an individual copper grounding conductor, such as copper wire, strap or braid. The grounding bus is securely connected to an effective electrical ground.

• Grounding the Mainframe

A grounding lug is provided on the rear of the console.

Connect the console grounding wire to the central grounding point for the studio. Do not count on metal cold water pipes as a console grounding point, as the use of plastic pipe and fittings or Teflon tape elsewhere in the line may place the pipe above ground potential. Also, condensation on cold water pipes can corrode ground connections.

It is also best to avoid the facility AC power ground as a grounding point, especially in old construction. While adequate for safety purposes, it may have a small voltage potential, and serve as a source for electrical noise in the system. In new construction, early consultation with the electrical contractor can result in an AC grounding system that is adequate for audio purposes.

One final tip: remember that metal equipment racks also provide a grounding path for any equipment mounted in them. This can be useful, as all equipment in a rack can be grounded via a single bus wire. However, it is easy to presume that a piece of rack mounted equipment is grounded only by its AC connector, when in fact it sees a second path to ground through the rack itself, thus creating a hidden ground loop.

4.4 Preparation for Electrical Installation

Tools required for installation include a soldering iron, RJ45 crimp tool and a small-gauge wire stripper/cutter. A heat gun is recommended so that the ends of all jacketed cables can be served with heat-shrink tubing.

The console wiring diagram should be drawn out ahead of time, for fastest installation, with all wires and connectors clearly designated. Professional installation practices recommend that wires, cables and connectors be numbered or labeled at the time of installation to match the wiring diagram. Wire ties, cable brackets and other accessories also should be on hand prior to installation.

Instead of connecting studio wiring directly to the console, many installers connect the console inputs, line level outputs and logic connections to intermediate telephone "punch blocks" mounted in a convenient location in the studio. The main advantage to this scheme is that console wiring assignments can be changed, and console audio and logic functions monitored, without disturbing the console operator. Contact your LPB dealer for information on standard practices, and on obtaining the punch blocks and associated accessories.

4.4.1 Connecting the Power Cord

The console mainframe should be grounded in accordance with your grounding. We highly recommend the use of an external surge suppresser to reduce the possibility of damage caused by lightning and other transients on the AC power line.

Insert the power supply plug into the rear of the console labeled POWER. Plug In the AC power cord. The OFF switches located on the mixer modules should be illuminated. DO NOT PROCEED IF THESE LAMPS FAIL TO ILLUMINATE. If you find this condition, check for AC at the wall outlet feeding the power supply. If this step does not restore normal operation then proceed no further. Call the LPB Customer Service department immediately.

Upon verification that power is available to the console, installation of the audio input, output and logic circuits can begin.

4.5 Audio Input Wiring

All audio inputs to the console are located at the rear of the console on RJ45 connectors.

Please note that the nominal input audio input level for this console is 0 dbm. This level is common on most professional audio equipment however consumer equipment quite commonly provides between –10 and –15 dbm of audio.

A good indicator of consumer equipment are the un-balanced connections such as RCA and phone jack connectors. Quite simply balanced audio has three connections, a Plus, Minus and Ground (or shield). Un-balanced audio has two connections, a Hot and Ground.

For your convenience a console will arrive with one MIC pre-amp cable (B501), one Consumer to line amp cable (B502) and 4 RJ45 to open leads (B500) which may be used for inputs and outputs.

With so many optional connections in both the professional and consumer audio market, it is impossible to provide cabling to meet every customers individual needs. We have provided a sampling of the cables which we offer as options.

RJ45 jacks contain eight wires each. Six of these are used for balanced audio input and the other two provide +/- 15 VDC to the B series of input amps. (see inside front cover)

The input wiring is clearly labeled on the bottom cover of the unit and are identical for each mixer (see the console outline drawing for general location).

4.5.1 General Installation Comments

Connect one audio source at a time, and check for RF interference and other problems before proceeding. It is advisable to connect a sensitive voltmeter or oscilloscope to the console Program output to monitor signal quality as each input is connected to the console. Any noticeable degradation in the console's noise floor should be investigated and eliminated before moving on to the next input.

Remember that FM RF interference usually is caused by rectification of a high RF signal level; AM RF interference usually is caused by a system ground loop (see Section 4.4). Telephone lines are often the cause of noise problems, and a 600:600 ohm isolation transformer is recommended at the console input for direct connection to the phone line. In high RF fields, proper grounding techniques are absolutely necessary.

Important: Never apply a phone line directly to the console. The presence of a ring voltage will cause damage to the circuitry.

4.5.2 Wiring the Inputs

RJ45 wiring is standard T568B and should be readily available at your local computer or phone supply store. LPB offers a series of pre-made input cables and amplifiers. Information is located on the inside of the front cover of the manual.

Pin 1 White/Orange Left +

Pin 2 Orange/White Left –

Pin 3 White/Green Right +

Pin 4 Blue/White GND

Pin 5 White/Blue GND

Pin 6 Green/White Right –

Pin 7 White/Brown -15VDC (not available on B500 Cables)

Pin 8 Brown/White +15VDC (not available on B500 Cables)

4.5.3 Microphone Inputs

Microphone inputs must first be brought up to Line level (0dbm). This is possible in a number of different options. The easiest option is to use the B501 Mic pre-amp Beissel provided with Blue.

If you have a need for more than one Mic input at a time you may order more B501’s or use an external Mic pre-amp or Mic processor as well.

NOTE: Ensure that external amps provide the Mic audio to both left and right channels. Some amps simply amplify the Mic audio however they do not add the audio to both left and right inputs.

• Phantom Power
  • Blue is not fitted with a phantom power supply.

    Using Mics with this requirement also require an external Phantom Mic power supply.

• Line Level Inputs

Line level input sources may be mono or stereo. Low impedance mono input sources should simply be paralleled across both left and right inputs. Care should be taken to avoid an impedance mismatch with high impedance mono sources. An impedance matching transformer or a resistive splitter network may be used. Observe correct polarity, and connect the shield to the adjacent frame ground pin.

Unbalanced equipment should be connected with careful attention to the grounding problems discussed in Section 4.4. The "hot" wire is usually connected to the plus input terminal, and the shield is connected to BOTH the minus input terminal and signal ground.

4.6 Audio Output Wiring

Program and Cue audio outputs from the console are on the RJ45 connector panel located on the rear of the unit. See the label on the bottom cover of the unit for directions.

The Program output is factory set to +4 dbm and is based on nominal input levels of 0 dbm.

The Cue and Send outputs are factory standard of 0 dbm and is based on nominal input levels of 0 dbm.

To adjust the mixer gain, set the fader to its normal operating position and select an input. Adjust the pot for the respective output located on the bottom cover of the unit. Program output is capable of +8 dbm. Cue and Send output is capable of +4 dbm.

Program and Cue audio outputs are balanced. Program output is Transformer isolated at 600 ohm impedance. Cue output is Active balanced at 10K ohm impedance. Program standard output level is +4 dbm. Cue standard output is 0 dbm. Recommended practice on balanced outputs is to use shielded twisted pair cable, with the shield connected at the load input, but not at the console output. This assumes proper grounding of the load equipment (see Section 4.4). Observe proper and consistent polarity when connecting output lines, and be sure to avoid bundling output cables with input cables (especially mic level cables).

4.6.1 Connecting Outputs to Unbalanced Equipment

Blue features both transformer and active balanced output circuitry; in other words, the (+) and (-) terminals of the active balanced output are driven directly by a pair of output amplifiers, and no output transformer is used. While these outputs can be connected to balanced loads just as transformers, their connection to unbalanced equipment should be undertaken with care.

The "hot" connection of the unbalanced equipment should be connected to the output's (+) terminal, and the (-) terminal of the output should be left unconnected. GROUNDING THE (-) TERMINAL OF THE OUTPUT MAY DAMAGE THE OUTPUT AMPLIFIER.

Most unbalanced equipment is consumer-grade, with a plastic case that offers no provisions for chassis grounding. In this case, it is possible to connect the "shield" connection of the unbalanced equipment directly to console ground without inducing a ground loop. It should be noted that the maximum output level will drop by 6 dbm in the unbalanced mode, since half of the output voltage has been effectively eliminated. This is not usually a problem, as most unbalanced audio devices have very sensitive inputs and do not require a large drive voltage.

Where the unbalanced equipment has a connector for chassis grounding, the preferred method is to leave the cable shield unconnected at the console, and connected to the shield terminal of the unbalanced device. The chassis ground of the external unbalanced device is then returned to the studio ground via a separate grounding conductor. This provides a dependable AC safety ground and an acceptable audio ground.

Unbalanced equipment usually has far more input sensitivity than required, and easily can be driven into overload by normal console outputs. In these cases, it is advisable to install an attenuator network at the console output, so that normal console operating levels are maintained.

4.7 Headphone Outputs

The Blue 5c console incorporate two stereo headphone amplifiers with unbalanced outputs rated at 1 Vrms to 8 ohm load. The headphone outputs can be used to directly drive 8 ohm or higher impedance headphones.

!!WARNING!!

Mono headphones should be avoided, as one channel of the headphone output will be shorted to ground. While current limiting resistors are included in the output, damage may still occur with prolonged use or high output levels.

The headphone output (1/4" stereo phone jacks) are located on the left and right front edge of the unit.

In the event that higher power levels are required, an external headphone amplifier may be used. Please contact LPB Customer Service for details.

4.8 Monitor Outputs

The Blue 5c is equipped with a stereo monitoring system. Any channel providing audio to the Program output (ON) will also send the audio to the Monitor Outputs. This line level, active balanced stereo output is used to drive an external monitor power amplifier or set of powered speakers.

Monitor outputs are subject to muting under various operational conditions (see Section 4.9.2). Output connections appear on ¼ " phone jacks located on the rear of the unit. These outputs are balanced, with a nominal output level of 0 dbm and a nominal impedance of 600 ohm

Monitor mute functions are engaged by placing the respective DIP switch in the ON position. Switches are located on the rear panel of the unit, respective to each of the ten inputs. See the label on the bottom of the unit for instructions.

Monitor level is controlled by a fader located on the right side of the unit.

• Connecting Monitor Amplifiers

Most modern power amplifiers need only a small amount of voltage to drive them to maximum output, which in many cases is greater than the power handling capacity of the monitor speakers. The low input sensitivity of these amplifiers is easily exceeded by the output voltage capability of most console outputs, so the installer is advised to consider protecting studio speakers by matching the output voltage of the console to the input requirements of the monitor amp.

Recommended practice calls for setting control room and studio monitor amplifier gains at installation, after which the amplifier controls are secured from tampering. The gain of the monitor amplifiers is set by determining the maximum voltage at the console's output, with its associated level control wide open. The gain of the monitor amplifier is set to reach maximum output (or maximum speaker power handling capability) when this voltage is presented to its input.

This is accomplished easily when the monitor amplifier has a simple attenuator pad level control across its input. However, most amplifiers today have a preliminary input stage before any level controls (consult your amplifier schematics). If this is the case, full console output can overload an amplifier input causing serious distortion and possible speaker damage. The preferred solution is to install a resistive pad at the amplifier input to reduce the console output to the desired voltage.

4.9 Logic System

The Blue 5c offers remote start logic for external equipment.

4.9.1 On Air Light

IMPORTANT: DO NOT CONNECT 120VAC DIRECTLY TO ANY TALLY CONTACT CLOSURE

5.0 Telephone Inputs and Mix Minus