
WARNING: The headphone amps are
designed to drive any standard head-
phones to a very loud level. We’re not
kidding! They can cause permanent hearing damage. Even intermediate
levels may be painfully loud with some headphones. BE CAREFUL! Always start with the PHONES level turned all the way down before connecting headphones to the PHONES jack. Keep it down until you’ve put on the headphones. Then turn it up slowly. Why? Always remember: “Engineers who fry their ears, find themselves with short careers.”
8. 48V Phantom Power Switch
Most professional condenser microphones require phantom power, which is a
This is a global phantom power switch and applies 48V to the XLR input connectors on channels
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.
9. Channel GAIN
The GAIN controls adjust the input sensitivity of the mic and line inputs on channels
If a
When using the balanced line input of the combo jack (1/4" TRS connector), there is 20 dB of attenuation all the way down, and 40 dB of gain fully up, with a “U” (unity gain) mark at about 10:00.
10. Signal Level Indicators
These LEDs indicate the channel’s signal level after the GAIN control and the INSERT jack.
If you’ve followed the “Set the Levels” procedure on page 6, the
11. Instrument Switch
Channels 1 and 2 have an extra button for switching between the MIC/LINE and Instrument inputs. When the button is out (MIC/LINE), the XLR MIC input or the 1/4" LINE input is used, and the Instrument input [12] on the front panel is disconnected. When the button is pushed in (Instrument), the 1/4" Instrument input is used and the XLR MIC and 1/4" LINE inputs are discon- nected. The input stage of the Instrument inputs is specially designed for the
Plugging a guitar straight into a typical
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 Instrument inputs on channels 1 and 2 make the need for a direct box unnecessary.
HOWEVER: The Instrument inputs are unbalanced, so if you are running a long cord between the instrument and the Onyx 400F (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.
12. Instrument Input
This is a 1/4" TS connector that accepts an unbalanced
Manual Owner’s
| ONYX MIC PRE |
| 1 ONYX MIC PRE |
| 2 ONYX MIC PRE |
| 3 ONYX MIC PRE | 4 | |||||
| OL | 20 U | 30 | OL | 20 U | 30 | OL | 20 U | 30 |
| OL | 20 U | 30 |
| 40 | 40 |
| 40 | 40 | ||||||||
48V | U | 60 | U | 60 | U |
| 60 | U | 60 | ||||
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| +40dB | +40dB | +40dB | +40dB | |||||||||
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| GAIN |
| GAIN |
| GAIN |
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| GAIN |
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Owner’s Manual | 13 |
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