Creative 1212M, 1820M owner manual Digital Cables, Grounding, Phantom Power, Unbalanced Cables

3 +48V

7 - Appendix

Useful Information

Unbalanced Cables

Unbalanced cables have one conductor and one ground (shield) and usually connect via unbalanced 1/4" phone plugs or RCA phono plugs. The shield stays at a constant ground potential while the signal in the center conductor varies in positive and negative voltage. The shield completely surrounds the center “hot” conductor and is connected to ground in order to intercept most of the electrical interference encountered by the cable. Unbalanced cables are more prone to hum and interference than balanced cables, but the shorter the cable, the less hum introduced into the system.

Digital Cables

Don’t cheap out! Use high quality optical fiber (for ADAT) and low-capacitance electrical cables (for S/PDIF) when transferring digital I/O to avoid data corruption. It’s also a good idea to keep digital cabling as short as possible (1.5 meters for plastic light pipes; 5 meters for high quality glass fiber light pipes).

Grounding

In order to obtain best results and lowest noise levels, make sure that your computer and any external audio devices are grounded to the same reference. This usually means that you should be using grounded AC cables on both systems and make sure that both systems are connected to the same grounded outlet. Failure to observe this common practice can result in a ground loop. 60 cycle hum in the audio signal is almost always caused by a ground loop.

Phantom Power

Phantom power is a dc voltage (+48 volts) which is normally used to power the pream- plifier of a condenser microphone. Some direct boxes also use phantom power.

Pins 2 and 3 of the AudioDock microphone inputs each carry +48 volts dc referenced to pin 1. Pins 2 and 3 also carry the audio signal which “rides” on top of the constant 48 volts DC. Coupling capacitors at the input of the AudioDock block the +48 volt DC component before the signal is converted into digital form. The audio mutes for a second when phantom power is turned on. After turning phantom power off, wait two full minutes before recording to allow the DC bias to drain from the coupling capacitors or this bias could affect the audio headroom.

1

(grd)

Balanced dynamic microphones are not affected by phantom

2power. An unbalanced dynamic microphone may not work properly, but will probably not be damaged if phantom power is left on.

Ribbon microphones should NOT be used with phantom power on. Doing so can seriously damage the ribbon element.

Since ribbon microphones are fairly specialized and generally expensive, you’ll know if you own one. Most microphones are either of dynamic or condenser type and these are not harmed by phantom power.

Appearance Settings in Windows

Adjusting the “Performance Options” in Windows will improve the screen appearance when moving the mixer around on the screen.

To Improve the Appearance Settings:

1.Open the Windows Control Panel. (Start, Settings, Control Panel).

2.Select System. Select the Advanced Settings tab.

3.Under Visual Effects, select Adjust for Best Performance. Click OK.

102 Creative Professional