CERWIN VEGA VCU85 (01) PDF Document

The CERWIN VEGA VCU85 amplifier includes the following features:

• Full Range Class D IR Chipset

• DirectFET Power Mosfet Output Stage

• SMD Technology on 4 layer Glass PC Board

• Conformal Coated PCB assembly for added water resistance

• ICAD circuit provides superior overload protection

• Frequency response 10 Hz – 30kHz

• Variable 12db crossovers

• Cerwin Vega Bass boost +12DB @45HZ (On select models)

• Premium 8 gauge power connections

• Multi channels / Mono channel options

• Remote Bass Knob (Included with MICRO81U/MICRO82U)

• 5 Channel has separate Front/Rear/Sub input – Perfect for DSP

Please observe the following precautions during installation:

• This unit is designed for negative ground 12V DC operation only.

• Total system impedance for the CERWIN VEGA VCU85 must not be less than 2 ohms bridged on the sub channel, and the main channels (Ch 1, 2, 3, 4) are 4 ohms bridged minimum.

• Avoid installing the unit where it would be subject to high temperatures (direct sunlight, hot air), rain, moisture, dust, or dirt.

• Do not cover the unit with carpet or wires.

• Do not use the unit with a weak auto battery. Optimum performance depends on optimum battery supply voltage.

• For safety, keep your car audio system volume moderate while driving so you can hear normal traffic sounds.

• There is no speaker level input connector. You can cut RCA’s and solder the wires to connect directly through the low-level input (RCA) or purchase an optional RCA Adaptor cable (model – CHHILVL) for a cleaner installation.

Although the CERWIN VEGA VCU85 amplifier incorporates heat sinks and protection circuits, mounting it in a tight space without air movement can damage internal circuitry over time. Choose a location with adequate ventilation around the amplifier. For easy setup, mount the amplifier so the side panel controls are accessible after installation. To increase thermal run times on low impedance loads, an additional fan is recommended. Observe the following precautions:

1. Using a felt pen, mark the mounting hole locations.

2. Mounting the amplifier on carpet will significantly reduce air flow, resulting in reduced thermal run times.

3. Mount the amplifier on a solid surface. Avoid mounting to subwoofer enclosures or areas prone to vibration. Do not install the amplifier on plastic or other combustible materials.

4. Before mounting, ensure you do not cut or drill into the fuel tank, fuel lines, brake lines, or electrical wiring.

Follow these precautions when wiring your CERWIN VEGA VCU85 amplifier:

1. Before installation, make sure the source unit power switch is in the OFF position.

2. Disconnect the negative (-) lead of the battery before making any power connections.

3. When making connections, be sure that each one is clean and secure. Insulate all connections to avoid damaging your equipment.

4. A secure, clean ground connection is critical for performance. Connect the ground directly to the car chassis to minimize resistance and avoid noise problems.

5. Add an external fuse on the amplifier’s positive (+) power lead, as close as possible to the vehicle’s (+) battery terminal. Use a fuse rating that equals the total current consumption at full output of all amplifiers in the system. This protects the vehicle from short circuits that could cause a fire.

These lights indicate when the amplifier is powered up normally and when there is a protection fault. The Protect LED is illuminated when there is a problem with your amplifier.

The Sensitivity control matches the preamp stage of the CERWIN VEGA VCU85 amplifier to your source unit. This is NOT a volume control. The range is between approximately 200mV to 10V. It can also handle speaker inputs of less than 25 watts RMS (typical OEM headunits are less than 25 W RMS, but not all).

The VCU series amplifiers, including the CERWIN VEGA VCU85, can be switched on and off using one of three methods, determined by the “Turn-On Mode” switch position. NOTE: DC and VOX turn-on settings ONLY work with speaker level input.

• **REM:** The standard 12V trigger wire.

• **DC:** DC offset (when connected high level in, this will sense differences in ground in your wiring through the speaker leads and turn on the amplifier).

• **VOX:** Signal sensing will sense any kind of signal input into the amplifier RCA, turning on the amplifier.

The most preferred and reliable method is the REM setting with a 12V trigger wire connected to the vehicle’s head unit switch output, which provides instant on and off. VOX and DC provide turn-on capabilities when a 12V trigger wire is not available but may have some delay.

The Crossover Selection Switch allows you to select the crossover type. Use High Pass (HP) for midrange or high-frequency speakers. Use Low Pass (LP) for subwoofers. In the FLAT position, the crossover adjustment knob has no effect, and all speakers will receive the full frequency range.

The Crossover Adjustment knob is used to adjust the crossover frequency. You must first select the HP, LP, or FULL range position on the crossover switch. The adjustment range is limited between 40-400 Hz for VCU82-VCU84 models. The VCU85 offers full range (FULL) or high pass (HP) for all channels. Selecting HP activates a fixed 70Hz crossover for full-range speakers. Channel 5 on the VCU85 can be full range or subwoofer and has an adjustable LP crossover from 25Hz – 250Hz.

The RCA jacks on the input harness allow for a normal Left and Right channel signal input. Simply connect to the source unit using RCA-type audio cables, keeping them away from power wiring wherever possible to reduce the risk of noise.

Use this switch on the CERWIN VEGA VCU85 when you are bridging the front 4 channels to be a big 3-channel amplifier. For the bridged output, use the Front positive (+) and the Rear negative (-) connections (4 ohms ONLY!).

Connect your speakers to the terminals on the harness. Stereo connections are connected as labeled. Bridged connections use the LEFT + and RIGHT – as the two connections. The CERWIN VEGA VCU85 sub channel is stable to 2 ohms minimum. DO NOT chassis ground any of the speaker leads, as this may cause unstable operation or damage to the amplifier and/or speaker.

The CERWIN VEGA VCU85 has a port for the remote level control (included). The control is intended to allow the user to control the level of gain up to the maximum adjustment level set on the amplifier. The control does not add additional boost; it only attenuates the setting that is fixed at the amplifier’s control panel.

These connections are for input power (+12V), chassis ground (GND), and remote turn-on (REM). Use a minimum of 8-gauge wiring for power and ground connections; 4-gauge is recommended for the mono block. The terminals will handle up to 8-gauge wiring (4-gauge on the mono block). Be sure any wiring that passes through metal has a grommet to protect it.

Amplifiers put an increased load on the vehicle’s battery and charging system. It is recommended to check your alternator and battery condition to ensure the electrical system has enough capacity to handle the increased load of your stereo system. Original equipment electrical systems in good condition should handle the extra load of any CVM amplifier without problems, although battery and alternator life can be reduced depending on your listening habits. To maximize performance, the use of a reserve power “Stiffening” capacitor (1 Farad per 1000W) like the Cerwin Vega Mobile products CVCAP2 is suggested.

1. **Plan Wire Routing:** Keep RCA cables close together but isolated from the amplifier’s power cables and any high-power auto accessories. When feeding wires through the firewall, use plastic or rubber grommets to prevent short circuits.

2. **Prepare Power Wire:** Strip 5/8 inch (15.9mm) of insulation from the end of the wire. Insert the bare wire into the B+ terminal on the amplifier and tighten the set screw.

3. **Install In-line Fuse:** The B+ cable MUST be fused 18 inches or less from the vehicle’s positive battery post. Install a waterproof fuse holder under the hood and ensure connections are watertight. Trim the power cable within 18 inches (45.7mm) of the positive battery post and splice in the in-line fuse holder. DO NOT install the fuse yet.

4. **Connect to Battery:** Strip 1/2 inch (12.7mm) from the battery end of the power cable. Crimp and solder a large ring terminal to the cable. Connect the ring terminal to the positive (+) battery post.

5. **Prepare and Connect Ground Wire:** Prepare the ground wire by stripping 5/8″ of insulation. Use a wire of the same gauge as the power connection. Insert the bare wire into the GND terminal and tighten the set screw. Prepare the chassis ground by scraping paint from a metal surface and cleaning the area of dirt and grease. Strip the other end of the wire, crimp, and solder a ring connector, then fasten it to the chassis with a non-anodized screw, star washer, and nut. It is important to upgrade the ground connection between the negative (-) battery post and the vehicle body for optimum performance.

6. **Prepare and Connect Remote Wire:** Strip 5/8 inch (15.9mm) of insulation from the end of the remote turn-on wire. Insert it into the REM terminal and tighten the screw. Connect the other end to a switched 12-volt positive source, usually the source unit’s remote amp turn-on lead. If unavailable, wire it to an accessory terminal in the car’s fuse block using a relay to isolate the amplifier.

1. **Mount the Amplifier:** Securely mount the amplifier to the vehicle or amp rack. Avoid mounting on cardboard or plastic panels, as screws may pull out due to road vibration or sudden stops.

2. **Connect Speakers:** Connect the car speakers. Speaker impedance should never be less than 2 Ohms stereo or 4 Ohms bridged. The VCU81 mono block is stable into 1 ohm. For most applications, 18-gauge wire is adequate for speaker leads. For leads longer than ten feet, 16-gauge wire is recommended. Pay careful attention to the polarity of the speaker terminals and ensure they correspond to the polarity on the amplifier. DO NOT chassis ground any speaker leads, as this can cause unstable operation or damage.

1. **Set Crossover:** Placing the x-over switch in the FULL position sets the amplifier to Full Range. For the VCU85, this allows ALL frequencies to pass. The VCU85 amplifier offers full range (FULL) or high pass (HP) selector switch for ALL channels. Selecting high pass (HP) will activate a fixed 70Hz cross over for full range speakers. Channel 5 (on VCU85) can be full range, or for subwoofers and has an adjustable (LP) crossover from 25Hz – 250Hz. For system tuning, start with the frequency around 80Hz and adjust as needed.

2. **Set Gain:** Turn the amplifier gains all the way down (counterclockwise). Turn the source unit volume up to almost full (usually about 2/3rds of the way up) or until the output starts to distort on an oscilloscope. This will be nearly full volume on some source units.

3. **Adjust Gain:** Increase the amplifier gain setting until adequate volume is achieved, or until distortion is audible, and then turn it down slightly until the distortion is inaudible. NOTE: Ideal signal-to-noise and dynamic range are achieved with the gain at a minimum. Most users find adequate gain and volume at less than halfway in the adjustment range. Avoid setting the gain very high, as noise and distortion will increase significantly.

4. **Fine-Tune Crossover:** The HP or LP crossover adjustment can now be fine-tuned. If using an HP configuration and you want the system louder, you can increase the HP Filter frequency and reset the “Gain”. Raising the HP frequency too high will cause a loss of mid-range and bass. If using an LP filter and you hear vocals from your subwoofer, turn the LP Filter frequency down (lower).

5. **Bass EQ/Boost (If applicable):** First, make sure any bass EQ on the source unit is OFF or FLAT. While playing music, slowly increase the level of the Bass EQ on the amplifier. You should notice a change between 0 and +12dB. If there’s not much difference, increasing the boost further will not provide any benefit. If the boost has audible benefits without adding distortion, find a level that suits your taste.

All CVM amplifiers, including the CERWIN VEGA VCU85, work with Cerwin Vega Bluetooth receivers (e.g., BTR7/9/10/12). When setting up a Bluetooth receiver, ensure the amplifier’s “TURN-ON MODE” is set to REM.

The BTR will pair to your phone or other Bluetooth device and allow playback through the amplifier. The CVM line of BTRs has 7 functions: Play, Pause, Volume up/down, Track up/down, Pairing, and Power on/off. Once paired, the BTR will auto-pair with the last connected device when powered on. The unit can remember up to 9 users and has memory without battery for up to 30 days.

To bridge a 4-channel amplifier, you can use “Y-Adaptors”.

1. Use a Y-Adaptor on the FRONT input (L/R) – this will now be the LEFT channel.

2. Do the same on the REAR input (L/R) – this will now be the RIGHT channel.

3. Connect the speakers to the BRIDGED connection on the amplifier. The FRONT connection is now LEFT, and the RIGHT connection is now REAR.

NOTE: You MUST connect ONLY a 4-ohm load when bridging!