Managing Gain Stages

Anyone with a cable TV box has juggled two volume controls. Set the cable too low, crank the TV, and you’ll hear too much background noise. With the cable too high, you can get distortion or a honky sound even with the TV volume low. Even a basic recording setup makes you manage multiple volumes, too. Here’s a Golden Mean approach for setting them.
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Anyone with a cable TV box has juggled two volume controls. Set the cable too low, crank the TV, and you’ll hear too much background noise. With the cable too high, you can get distortion or a honky sound even with the TV volume low. Even a basic recording setup makes you manage multiple volumes, too. Here’s a Golden Mean approach for setting them.

Your Keyboard’s Volume Control

An old rule says to leave it at maximum, then set levels for recording on your mixer or audio interface. That’s a good place to start, but on some keyboards, full throttle might make hiss audible while almost-full volume sounds clean. Call up the sound you’ll record with, but don’t play. Move the volume knob or slider slowly from low to high, and listen carefully for background noise. If an increase happens, most likely towards the top of the range, back off until it goes away. Chances are, any making up you’ll do using the gain control of the gear that’s listening won’t add as much noise; if it does, the process is easy enough to undo.

Don’t forget MIDI volume. Make sure a pedal, other controller, or even the sound program itself isn’t keeping it below maximum (127) without you knowing. Also, the edit menus of some synths have an output parameter that works in the digital domain—another option if you need hotter levels without added noise.

Faders and Gain Knobs

Next come the inputs of your audio interface, compact mixer, or standalone recorder. Either you’re in a channel (or two) with an input gain knob—also called trim or sensitivity, which are not the same as faders on the device or in your DAW’s mixer window — or you’re not.

In the first case, leave the channel fader at “unity,” usually indicated by a zero located most of the way up the fader’s travel range, and start with the trim all the way down. Play as loud as you mean to and adjust the gain until your loudest peaks hit the “yellow” zone on your physical or onscreen mixer’s meter, but not the red. With most keyboards, you’ll turn up the trim very little, or not at all, unless something else in the chain is quieting the signal first.

This is why many audio interfaces and compact mixers have trim knobs only on their mic inputs: Line-level ins are pre-optimized for things such as keyboards. If your keys are too quiet no matter what, you may wish to go for the extra gain of a mic channel. Otherwise, it’s one less volume control to worry about. Depending on how your mixer works, the channel fader may or may not have any effect on the level that’ll get recorded, and it may not have any visible effect on the meter, depending on your setup. If not, don’t be afraid to lower your keyboard’s volume a bit more if it’s still too hot.

What sounds too loud or too soft through your listening system may be the perfect level for the A-D converters of the audio interface or recorder itself, so use only your headphone, “monitor out,” or “control room” volume to get a comfortable listening level.

Soft Synth Secrets

Many soft synths have their own volume control in the plug-in window, and the rules are different for soft synths. Push the soft synth’s volume too high, and often, you’ll overload its mixer channel in the host program, distorting the sound. Try this advice from recording engineer Orlando Rashid (Jamie Foxx, Ludacris, Snoop Dogg): “Insert a compressor plug-in on the audio or instrument channel where the soft synth lives. Set it so it’s not really compressing, or just barely hitting. Keep the soft synth’s volume on the low side, and use the compressor’s output or make-up gain to make it louder.” Some DAWs also have simple “trim” plug-ins, useful for adjusting software instruments that don’t have their own volume.

This article was originally published in Keyboard magazine’s mammoth June 2006 “Record Your Boards” issue.