1. Introduction
The Marantz MM7055 is a high-performance 5-channel power amplifier designed to enhance your home theater audio experience. It delivers 140 watts of high-current output per channel, making it suitable for driving demanding speakers in a 5.1 home theater system. This amplifier supports both balanced (XLR) and single-ended (RCA) inputs, offering flexible connectivity options. Its robust construction and advanced circuitry ensure stable and accurate audio reproduction.
Key features include:
- 140W (8 ohms, 20Hz-20kHz) x5 Power Amplifier
- Current feedback power amplifier with Marantz HDAM circuit
- XLR & RCA inputs for all 5 channels
- Detachable Power Cord
- New stylish front design
Figure 1: Front view of the Marantz MM7055 5-Channel Power Amplifier, showcasing its sleek black finish and central illuminated porthole display.
2. What's in the Box
Upon opening the package, please verify that all the following items are included:
- Marantz MM7055 5-Channel Power Amplifier
- Detachable Power Cord
- Owner's Manual (this document)
- Other accessories as specified by the manufacturer (e.g., remote control, batteries if applicable, though not explicitly listed for this amplifier)
3. Setup and Connections
Before connecting the amplifier, ensure all components are powered off and unplugged from the wall outlet. Refer to the rear panel diagram for connection points.
Figure 2: Rear view of the Marantz MM7055, displaying the balanced (XLR) and single-ended (RCA) inputs for each of the five channels, along with the gold-plated speaker terminals and remote control connections.
3.1. Audio Input Connections
The MM7055 offers both balanced (XLR) and single-ended (RCA) inputs for each channel. Choose the input type that matches your pre-amplifier or AV receiver's outputs for optimal signal integrity.
- XLR (Balanced) Inputs: For professional-grade connections, connect XLR cables from your pre-amplifier's balanced outputs to the corresponding XLR inputs on the MM7055.
- RCA (Single-Ended) Inputs: For standard connections, connect RCA cables from your pre-amplifier's RCA outputs to the corresponding RCA inputs on the MM7055.
- Ensure that the input selector switch (if present, or automatically detected) for each channel is set correctly for the type of cable used.
3.2. Speaker Connections
The MM7055 features gold-plated, four-way binding post speaker terminals. Use high-quality speaker wire for the best performance.
- Identify the positive (+) and negative (-) terminals on both your speakers and the amplifier.
- Connect the positive (+) terminal of each speaker to the corresponding positive (+) terminal on the amplifier.
- Connect the negative (-) terminal of each speaker to the corresponding negative (-) terminal on the amplifier.
- Ensure all connections are tight and secure to prevent signal loss or short circuits.
- The MM7055 is capable of long-term power delivery into low-impedance speakers.
3.3. Power Connection
Connect the detachable power cord to the AC inlet on the rear of the amplifier, then plug the other end into a suitable wall outlet.
4. Operating Instructions
4.1. Powering On/Off
- To power on the amplifier, press the "POWER ON/STANDBY" button located on the front panel. The illuminated porthole display will light up.
- To put the amplifier into standby mode, press the "POWER ON/STANDBY" button again.
- For total remote control convenience, the MM7055 includes input and output jacks for DC trigger pulses as well as RC-5 jacks, allowing integration with compatible control systems.
4.2. Audio Playback
Once connected to a pre-amplifier or AV receiver, the MM7055 will amplify the audio signals received from your source components. Adjust the volume and select audio modes via your pre-amplifier or AV receiver.
The MM7055 is ideal for a 5.1 home theater system, providing powerful and clear audio for movie soundtracks and music. For more complex home theater systems, the MM7055 can be paired with one or several MM7025s (sold separately) to create an immersive 7.1 or 9.1 audio experience.
5. Maintenance
5.1. Cleaning
To maintain the appearance of your amplifier, wipe the exterior surfaces with a soft, dry cloth. Do not use abrasive cleaners, waxes, or solvents, as these may damage the finish. Ensure the unit is powered off and unplugged before cleaning.
5.2. Ventilation
The MM7055 employs an extruded aluminum thermal tunnel with temperature-sensing forced air cooling for efficient heat dissipation. Ensure adequate ventilation around the amplifier to prevent overheating. Do not block any ventilation openings. This configuration assures cool operating temperatures for long-term reliability, even under substantial output.
6. Troubleshooting
If you experience issues with your Marantz MM7055, please consult the following common troubleshooting steps before seeking professional service.
- No Power:
- Ensure the power cord is securely connected to both the amplifier and a working wall outlet.
- Verify the wall outlet is supplying power (test with another device).
- Check if the "POWER ON/STANDBY" button has been pressed.
- No Sound:
- Confirm that all audio input cables (XLR or RCA) are securely connected between the pre-amplifier/receiver and the MM7055.
- Check all speaker wire connections at both the amplifier and the speakers, ensuring correct polarity (+ to + and - to -).
- Verify that your pre-amplifier/receiver is powered on, has a source selected, and its volume is turned up.
- Ensure the correct input type (XLR/RCA) is selected on the amplifier if there is a manual switch (though typically auto-sensing).
- Distorted Sound:
- Check all cable connections for looseness or damage.
- Ensure speaker wires are not frayed or shorting.
- Reduce the volume level from your pre-amplifier/receiver to see if distortion persists, indicating potential clipping.
- Verify that the impedance of your speakers is compatible with the amplifier.
- Overheating:
- Ensure the amplifier has adequate ventilation and is not placed in an enclosed space without airflow.
- Remove any objects blocking the ventilation openings.
- Allow the unit to cool down if it has been operating at high volumes for extended periods.
The chassis of the MM7055 is heavy gauge steel, designed to provide maximum isolation from external vibration and minimize electromagnetic and radio frequency interference, contributing to clear, uninterrupted sound.
7. Specifications
| Feature | Specification |
|---|---|
| Model Number | MM7055 |
| Channels | 5 |
| Power Output (8 ohms, 20Hz-20kHz) | 140 Watts per channel |
| Amplifier Type | Current Feedback Power Amplifier with Marantz HDAM circuit |
| Inputs | XLR (Balanced) x5, RCA (Single-Ended) x5 |
| Speaker Terminals | Gold-plated, Four-Way Binding Posts |
| Product Dimensions (L x W x H) | 15.16 x 17.32 x 7.26 inches |
| Weight | 15.65 Pounds |
| Power Cord | Detachable |
| Date First Available | September 1, 2010 |
| Manufacturer | Marantz |
8. Warranty and Support
Marantz products are designed for reliability and performance. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official Marantz website. Warranty coverage typically includes defects in materials and workmanship for a specified period from the date of purchase.
For technical support, service, or inquiries regarding your MM7055 amplifier, please contact Marantz customer support or an authorized service center. Contact information can usually be found on the Marantz website or in the documentation provided with your product.
Note: Protection plans offered by third parties (e.g., Amazon Protection Plans) are separate from the manufacturer's warranty and have their own terms and conditions.
