Phoenix Audio DRS-2 - Stereo Class A Microphone Pre-Amplifier/DI - Manual (Page 4)

Additional Setup Information
Firstly, unlike a lot of mic-pre's, the Yellow LED is not a warning that the
output of the unit is clipping. It is purely there to indicate +8dB output
level.
The DRS units were originally fitted with a Green LED (0dB) and a Red LED (+8dB), but we
found that the Red LED was making users believe that the unit was clipping (Red = danger =
clipping) which was NOT the case, so this was changed to a Yellow LED in later models so
that users tended to not regard it as a "Clipping" LED.
You can turn the output knob all the way up to maximum and still be sure the
output of the unit will not clip. The amount of headroom on both the input AND output
stage is HUGE!!! There will never be a time when you can't get a hot enough
output, only occasionally too hot an input (then you just simply turn down
the input gain knob (in Mic mode).
The best thing to do is ignore the Yellow LED if you want a very hot output,
and set the unit up as follows:
When the DRS is switched into DI mode, the Mic-Sensitivity switch becomes disconnected
and not in use in DI mode..
For Microphone Input:
1: Set the output knob to about the 2 'O' Clock position. (or just over
half-way)
2: Set the mic input level so that the green LED is just beginning to come on
solidly. (this indicates 0dB OUTPUT level)
3: If the Yellow LED is coming on (+8dB OUTPUT level) and you think the unit is clipping it
is NOT
the output stage, just step the input gain knob back one click.
4: Turn the output knob up to the level you would like (If you wanted a very hot output level,
ignore the Yellow LED.
I'll try to explain a little more.............The LED's on the front panel
are there to give you an indication of output level only (0dB and +8dB, corresponding to 4
and 6 on a PPM Meter),
this is because most semi-pro (and indeed, a lot of Professional!) equipment
cannot handle the full output of the DRS-2, and the LED's give you a good
indication of output level so that you can determine where in the audio
chain you may be getting clipping. They do NOT indicate that the DRS-2 is
clipping.
The only place you might get clipping on the DRS-2 is in the INPUT stage
(although the headroom on the INPUT stage is very high!)........ So if you
believe the DRS-2 IS clipping, just turn the INPUT down, but the OUTPUT can
be turned up to maximum if you wanted.