M-Audio Duo USB [12/27] Setting the gain

jacks. Check your source or target device’s documentation for more information

on its operating line level.

Using the Mic Inputs

The Duo gives you two completely independent channels of high gain, ultra low

noise pre-amps. Each channel provides low impedance microphone inputs on

XLR connectors with optional phantom power. Dynamic, condenser, or any type

of low impedance microphone will interface easily with the Duo’s Mic Inputs.

You may also attach a direct box or passive transformer to the Duo’s Mic Inputs,

which will then allow you to plug an electric or acoustic guitar or other high

impedance instrument into the Duo’s Mic Inputs. This is also described in the

previous section, “Hooking Up Your Duo.” Additional information on using the

Mic Inputs will be found in the next three sections.

Setting the Gain

The Duo provides up to 60dB of gain on the XLR “Mic” inputs. Microphones

typically emit a low signal level, requiring a "pre-amp" such as the Duo provides.

Other instruments, such as guitar pickups and keyboard sound modules, may also

benefit from a little bit of punch from the Duo, when used in conjunction with a

direct box or passive impedance transformer.

Plug in your mic or instrument with the gain controls turned down, then turn the

gain up incrementally while testing the mic or playing the instrument. When the

signal LED shows fairly consistent activity, you’ve reached a good signal level

for the Duo mic preamp. Some users may wish to experiment a little further to

find what audibly might be referred to as a "sweet spot." Note that when the

"clip" LED lights, it is indicating that the signal is clipping. Let your ears be the

judge, but when the clip LED lights and stays lit, you are approaching or have

reached distortion in your Duo signal.

You must also consider the level that is being sent from the Duo to your

recording software. Check the input meters within your software and make sure

that they are neither too low nor clipping (too ‘hot’). An adjustment in gain on

the Duo may be necessary, but your optimal recording level within your software

should be approaching but never reaching the maximum level.

You will find more information on setting record levels in the manual of your

music software. Understand that in digital recording, clipping is never a good

thing. If your level goes into the red once, you’ve got distortion!