Peavey AAM 1662 User Manual page 13

Gain Structure
Gain Structure (continued)
Step 3. Adjusting input gain.
With audio applied, slowly bring up the gain control clockwise from its minimum position. At the same time, look at the mas-
ter Left/Right meters. The correct setting of the gain control is determined by the 0 dB position on the meters. When the nom-
inal level of the audio input source is reading consistently at or near the 0 dB mark on the master Left/Right meters, the gain
control is set correctly.
When the gain control is set, leave it alone. As long as the audio source does not change significantly, this setting should work
fine for most applications. To adjust "volume" for the input, use the fader. Naturally, subtle adjustments of the gain control
may be necessary during performance or use, but if you set it correctly, using this procedure, these changes should be rare.
Adjust Gain control....
Step 4. Rinse & Repeat.
If your input level is reading correctly, and you are relatively sure that the input source level will not change significantly, then
move on to the next channel. Repeat this process for every input in the system, making sure that the input sources are as close
to reality as possible. We have all been through a show where we arrived early just to set gain structure, only to have the input
source changed 10 minutes before show time! It is very important that you know what the input source is, and what the nomi-
nal level will be.
Step 5. Adjust, adjust & adjust again!
Obviously, additional adjustments are always required. The input levels vary, the program material may change or the entire
scope of the application may change, sometimes without you even knowing it.
Most of your adjustments should be based on fader movements, and not the gain controls. A proper gain control setting pro-
vides the best performance for the input amplifier, the summing bus and the output stage. When you bring all of the faders up,
the summing effect will create a higher meter reading than you saw when you adjusted each individual channel. A simple
adjustment of the faders will usually correct this.
Remember this, your Left & Right master meters will tell you what you need to know for most applications. If the total, com-
bined level of your inputs is jumping around 0 dB, then you are in good shape. (That is, if you followed the previous proce-
dures.) If your faders are full-tilt-boogie, and the meters peak at -9 dB, then you've got a serious gain structure problem. The
same is true if you are constantly in the red, driving the outputs into distortion.
Finally, try and understand that a mixer is a single device in the audio system. You cannot use the master output faders to get
additional level from your power amplifier! If you have the gain structure for the AAM
are reading happily at 0 dB, then you have good audio. If it's not loud enough, then you will need to investigate the next device
in the system, after the AAM 1662.
Peavey Electronics Corp
....so that audio level reads at or about
the 0 dB mark on these meters.
1662 set up properly, and your meters
™
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