System Input Level Calibration Using the Meter LEDs

Chapter 6 Maintenance & Service

The MMR-8 requires little maintenance other than ensuring adequate airflow through the interior of the unit. Do not use alcohol or other common studio chemical cleaners on the front panel keys.

The rear panel maintenance is to vacuum and/or brush off the fan opening area of the power supply if a build-up of dust occurs.

System Input Level Calibration Using the Meter LEDs

The LED meters are factory aligned for +4 dBu analog operating levels. Thus a +4 dBu input level will yield a 0 VU indication. There are no meter calibration trim pots in the MMR-8, only trim pots for setting the analog input and output signal levels.

The LED meters can be set to indicate various headroom operating levels, however. The industry de facto standard (and MMR-8 default setting) is for 0 VU to indicate an absolute level of -20 dBFS (20 decibels below digital full scale). This setting determines the amount of headroom in the system before digital clipping occurs. This setting is adjustable from -15 dBFS to -24 dBFS. Use Setup Menu 520 to select the meter reference level.

For in-system calibration of the input signal levels, there is a calibration mode that uses the meter LEDs to indicate input level in steps of .333 dB, 1.0 dB, or 3 dB. Setup Menu 521 sets the MMR into this calibration mode. The default setting is Off for a normal meter display. To monitor the input level, use Menu 521 to set the calibrate mode ON. At the source, adjust the input source levels so that the meter LEDs up to and including the 0 LED are on, indicating an input level of +4 to +4.33 dBu. Once calibration is complete be sure to restore Setup Menu 521 back to Off for regular meter indication. The input and output calibrations can be checked with the MMR-8 rack mounted, but to actually adjust the input or output trim pots the MMR-8 must be removed from the rack and the top cover removed.

MMR Input and Output Level Calibrations

Use the following procedure to calibrate the MMR-8 Input Converter board (MIC), and the MMR-8 Output Converter board (MOC). This procedure assumes that both of these cards are in the unit. It is assumed that an electronics technician who has experience operating audio measurement equipment is performing the calibration.

The following equipment is required to perform calibration adjustments:

1.A Low distortion, accurate balanced input/output audio analyzer/generator (Audio Precision System 2 or equivalent). A digital multi-meter with AC rms volts measurement capability, in conjunction with a function generator with a sine wave output as a signal source may also be used. However, the AP equipment will provide more accurate measurements, and the settings/displays will be in the proper units

2.Plastic Potentiometer Adjustment screwdriver/tweaker.

3.Input and Output cables compatible with the MMR-8 analog Audio In/Out connectors (equivalent to Tascam DA-88 analog audio cables).

MMR-8

Tascam MMR-8 Owner’s Manual • Chapter 6 • Maintenance and Service

MMR-8 specifications

The Tascam MMP-16 and MMR-8 are two innovative products designed to meet the specialized needs of audio professionals, offering advanced features and capabilities suitable for various recording and playback applications.

The Tascam MMP-16 is a versatile audio router and mixer that excels in different environments, from live sound to studio recording. One of its primary features is the 16-channel configuration, allowing for significant flexibility in signal routing. The MMP-16 supports multiple audio formats, including analog signals, making it adaptable to a wide range of setups. It boasts high-quality AD/DA conversion, delivering excellent audio fidelity and low latency performance.

Additionally, the MMP-16 is equipped with comprehensive digital processing capabilities, including EQ and dynamics processing on each channel. This makes it ideal for both mixing live performances and preparing recordings for post-production. The unit's user-friendly interface includes an intuitive display and physical controls that streamline operation, making it easy for both novice and experienced engineers to navigate.

On the other hand, the Tascam MMR-8 is a robust multi-track digital audio recorder that offers exceptional reliability for professionals who require high-quality audio capture. This 8-channel recorder shines in its ability to handle various digital audio formats, ensuring compatibility with different workflows. One standout feature of the MMR-8 is its solid-state recording technology, which enhances durability and reduces the risk of data loss, a crucial aspect in high-stakes recording environments.

The MMR-8 also provides comprehensive onboard monitoring options, allowing users to assess audio quality in real time. Its extensive connectivity options include digital and analog inputs and outputs, facilitating seamless integration with other studio equipment and live sound systems. The data management capabilities of the MMR-8 make it easy to organize and retrieve recordings, while its compact design ensures portability without compromising on performance.

Both the MMP-16 and MMR-8 showcase Tascam's commitment to innovation and quality in the audio industry. Their advanced features, coupled with solid build quality and ease of use, make them essential tools for audio professionals seeking reliable solutions for their recording and mixing needs. Whether utilized separately or in conjunction, these devices amplify creativity and enhance the overall audio production experience.