Jeff Rowland Design Group Model 2 manual Operation

Operation

After following the procedures outlined in the Installation/Rear Panel Power Connections and Signal Connections sections, the Amplifier can be turned on by pressing the FRONT PANEL STANDBY/POWER button. Allow approximately twenty (20) minutes for the amplifier to reach operating temperature and maximum performance potential. A short warm-up time is dependent upon the amplifier being plugged in to an active AC mains power source for at least two hours prior to activating the FRONT PANEL STANDBY/POWER button. Therefore, it is recommended that the Amplifier be continuously connected to an active AC mains power source.

If you desire to disconnect the AC mains for an extended period of time, simply disconnect the AC power cable from the wall outlet and reconnect upon your return. Slight transients may be heard in the loudspeakers during the AC mains connect/disconnect transitions.

Your new Model 2 Amplifier will require an initial break-in period of at least eighty (80) hours before maximum performance can be expected. Efficient break-in procedures require the Amplifier to be fully operational (playing music). Continuous and noticeable performance improvements will occur during subsequent months of operation.

To achieve the maximum performance for which this Amplifier was designed, it is recommended that balanced signal source (INPUT) and LOW INPUT IMPEDANCE options are used. This condition requires that the driving source component (preamplifier) is equipped with balanced outputs and sufficient output current to properly drive the input of the Model 2 when the LOW INPUT IMPEDANCE option is selected. Most high-quality solid state pream- plifiers can satisfy these conditions, and best results are obtained when the output impedance of the preamplifier (600Ω balanced) matches the input impedance of the power Amplifier (600Ω balanced). When the impedances are matched, maximum signal power transfer and signal fidelity are achieved in addition to the advantage of utilization of long lengths (10 meters and greater) of interconnect between components with no sonic degradation. However, there will be a 6 dB decrease in volume relative to a mismatched condition (low driving source impedance driving high load (Amplifier input) impedance).

If there is any doubt as to the compatibility of the above mentioned components, then HIGH INPUT IMPEDANCE should be selected. Since the electrical performance of the Model 2 is not changed when selecting different INPUT IMPEDANCE options, apparent differences in sonic quality can be attributed to mismatched impedances.

Due to different sensitivities of associated equipment used with the Model 2, the OVERALL GAIN switch can be used to optimize the total gain structure of the entire system. This allows the volume control of your preamp to be used in an ideal mid-range position.