GTR AMPLIFIERSSetting the input level controlsTo match your amplifier’s input sensitivity (gain) to your source unit’s output level, we recommend the following procedure:A. Turn both input level controls counterclockwise to MIN (minimum).B. Play a dynamic music track through your source unit. Turn the source unit’s volume control to the 3/4 position.C. Turn front input level control dial clockwise towards MAX until it no longer sounds clear and there are crackling, crunching, hissing or other types ofdistortion interfering with the distinct sounds of a musical instrument.D. Slowly turn the front level input control dial counterclockwise until the music sounds clear again, then note or mark where the dial is. That mark is nowyour maximum volume setting for clear audio.E. Your front input level is now correctly set. Repeat this process with the rear channels.Setting the crossover (GTR-102, GTR-104, GTR-7535)Properly setting crossover filter selectors optimizes frequency distribution for efficient speaker operation and best sound.Step 1: Use the slider controls to select low-pass (LP), FULL, or high-pass (HP).• LP: Low pass. Choose this setting if you are connecting a subwoofer(s) or want to provide a low-pass filter for separate mid-bass speakers. NOTE: theGTR-601 and GTR 1001 feature low-pass crossovers only.• FULL: Full range. Choose this setting if you are connecting full-range speakers and are not using a subwoofer in your system.• HP: High pass. Choose this setting to prevent low bass from reaching midrange or full-range speakers when you are using a subwoofer in your system.Step 2: Use crossover-filter frequency controls to adjust crossover point settings for coaxial speakers and subwoofers to suit listener preference. Turn thedials to the left to lower the crossover point and to the right to raise the crossover point. Exact crossover settings for coaxial speakers and subwoofers finallydepend on your listening preferences. NOTE: crossover point does not apply in FULL mode.Adjusting the subwooferSelect INT if you’re connecting a subwoofer to the GTR-7535 amplifier and if your source unit does not feature a subwooferoutput (this will send a summed audio signal to the subwoofer). If your source unit does feature a subwoofer output, selectEXT to connect to that output.Selecting subwoofer Phase (GTR-601, GTR-1001, GTR-7535)You can choose a subwoofer phase output of 0° or 180°. To check your sub’s phase, play music with lots of bass and listenas another person slowly flips the 0/180 degree phase switch back and forth. The correct setting is the one that gives youmore bass. If you don’t detect any real difference, leave the switch in the O setting.Bass Boost EQ (GTR-601, GTR-1001, GTR-7535)Bass Boost EQ gives you the ability to increase the bass output from 0 dB to +12 dB.BASS BOOST0dB +12dB• •A B C D EPHASE0º 180ºSUB INPUTINT EXT9