Mackie 800R owner manual BIT Depth

6. 48V Phantom Power Switch

Most professional condenser microphones require phantom power, which is a low-current DC voltage delivered to the microphone on pins 2 and 3 of the XLR microphone connector. Push in the 48V button if your microphone needs phantom power. An LED lights next to the button to indicate that phantom power is active on that channel.

Dynamic microphones, like Shure’s SM57 and SM58, do not require phantom power. However, phantom power will not harm most dynamic microphones should you accidentally plug one in while the phantom power is turned on. Be careful with older ribbon microphones. Check the manual for your microphone to find out for sure whether or not phantom power can damage it.

7. Signal Level LEDs

These LEDs indicate the channel’s signal level after the GAIN control.

If you’ve followed the “Set the Levels” procedure on page 5, the –20 and 0 LEDs should light frequently, and the OL (Overload) LED should not light at all. If the OL LED is blinking frequently, the signal is probably distorted from overdriving the input. Either turn down the GAIN control or turn down the signal at its source.

HOWEVER: The HI-Z inputs are unbalanced, so if you’re doing a live show and running a long cord between the instrument and the mixer (say over 25 or 30 feet), it is best to use a direct box with a balanced output to avoid picking up noise over the length of the cord.

10. POWER Switch

This one is self-explanatory. When the POWER switch is turned ON (up), power is supplied to the Onyx 800R.

11. SAMPLE RATE Switch

Turn this switch to select the sample rate used by the analog-to-digital converters (ADCs) and the digital output.

This eight-position switch offers the following selections: 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz, and EXTERNAL. The LED next to the selected sample rate lights to indicate the sample rate currently being used.

If EXTERNAL is selected, the 800R locks to the exter- nal clock connected to the EXTERNAL WORD CLOCK IN connector [19] on the rear panel.

For any of the internal sample rate settings, the ADAT OPTICAL OUT and the AES/EBU OR S/PDIF OUT run at the selected sample rate, which is detected by the device to which the Onyx 800R is connected.

Owner’s Manual

8.UNBAL HI-Z Instrument Input (Channels 7-8)

This is a 1/4" connector, which accepts an unbalanced instrument-level input signal from a high-impedance instrument like a guitar.

9. MIC/LINE/HI-Z (INST) Switch

Channels 7 and 8 have an extra button for switching between the MIC/LINE and HI-Z inputs. When the but- ton is out (MIC/LINE), the XLR MIC input or the DB25 LINE input is used, depending on the setting of the MIC/LINE switch [2], and the HI-Z input is disconnect- ed. When the button is pushed in (HI-Z), the 1/4" HI-Z input is used and the XLR MIC and DB25 LINE inputs are disconnected. The input stage of the HI-Z inputs is specially designed for the high-impedance pickups on electric guitars, basses, acoustic guitar pickups, etc.

Plugging a guitar straight into a typi-

cal line input can result in the loss of

high frequencies, causing an unnatural

and dull sound. Normally, you must use a direct box between a guitar and a

mixer’s or preamplifier’s input, which serves to convert the impedance of the guitar from high to low. The HI-Z inputs on channels 7 and 8 make the need for a direct box unnecessary.

12. LOCK

As described above, if EXTERNAL SAMPLE RATE is selected, the 800R locks to the the EXTERNAL WORD CLOCK IN on the rear panel. If there is not a valid clock connected to the EXTERNAL WORD CLOCK IN, the LOCK LED flashes, indicating the problem. If a valid ex- ternal clock is detected, the LOCK LED lights continu- ously and the corresponding sample rate LED will light.

13. BIT DEPTH

This button determines the word length at the digital output, and toggles between 24-bit and 16-bit. The corresponding LED above the button lights to indicate the selection. You might use 24-bit when recording to a 24-track hard disk recorder or DAW, and 16-bit when re- cording direct to 2-track on a CD-recorder or DAT deck.

When 16-bit is selected, a dithering algorithm is applied to the digital signal to improve the dynamic range and reduce low-level distortion, called quantization noise.

ANALOG MIC PREAMP WITH 192kHz DIGITAL OUTPUT

ON
32kHz	96kHz	LOCK	24	16
			BIT	BIT
				(DITHER)
44.1kHz	176.4kHz
48kHz	192kHz
88.2kHz	EXTERNAL	SAMPLE RATE	BIT
			DEPTH
	Owner’s Manual				11