Usb Rec Src Select Switch; Xlr And 1/4" Combo Inputs; Phantom Power - Mackie big knob studio Owner's Manual

4. USB Rec Src Select Switch

You want options, you've got options! The Big Knob
Studio and Big Knob Studio + grant you the opportunity
to choose between recording paths for a multitude of
applications, one of which is yours!
This two-position latching switch simply allows you
to choose which USB source you would like to use for
recording:
With the switch disengaged [2-track], the signal
at the 2-track and monitor outputs is recorded. In other
words, the signal seen at the USB inputs is a mirror
image of the 2-track signal.
With the switch engaged [inputs 1/2], only the Onyx
mic preamps – channels 1 and 2 – are delivered to the
DAW via USB sends 1/2.

5. XLR and 1/4" Combo Inputs

These dual Onyx Wide-Z preamps accept both
balanced microphone inputs from an XLR connector
and balanced and unbalanced line-level inputs from
a 1/4" TRS connector. The microphone preamps feature
our Onyx design, with higher fidelity and headroom
rivaling any standalone mic preamp on the market
today.
They are wired as follows, according to standards
specified by the AES (Audio Engineering Society).
Balanced XLR Wiring:
Shield (Ground)
Hot (+)
Cold (–)

Phantom Power

Most modern professional condenser mics require
48V phantom power, which lets the interface send
low-current DC voltage to the mic's electronics
through the same wires that carry audio. (Semi-pro
condenser mics often have batteries to accomplish the
same thing.) "Phantom" owes its name to an ability to
be "unseen" by dynamic mics (Shure SM57/SM58, for
instance), which don't need external power and aren't
affected by it anyway.
Phantom power may be selected by depressing
the Big Knob's phantom power switch on the top panel.
Never plug single-ended (unbalanced)
micro phones, or ribbon mics into the mic
input jacks if phantom power is on. Do not
10
Big Knob Studio & Studio + Monitor Controller | Interface
Pin 1
Pin 2
Pin 3
2
SHIELD
HOT
3 1
COLD
SHIELD
1
3 COLD
2
HOT
plug instrument outputs into the mic XLR input jacks
with phantom power on, unless you are certain it is safe to
do so. Be sure the channel's gain control is turned down
when connecting microphones to the mic inputs when
phantom power is turned on, to prevent pops from getting
through to the speakers.
The 1/4" jacks share circuitry (but not phantom
power) with the mic preamps, and can be driven by
balanced or unbalanced sources.
Additionally, both channels may accept Hi-Z sources
(such as guitars) via the 1/4" input without the need
for a separate DI box.
• Unbalanced TS (tip-sleeve) lines can be accommodated
via the TRS jack. Make sure the cable terminates with
a TS plug (like a guitar plug), or if it's a TRS plug (such
as a headphone plug), make sure the ring is tied to the
sleeve and that the plug is fully inserted into the jack.
These inputs are mono-summing (to both busses), but
stereo when the stereo pan switch (located on the top
panel) is engaged. This way, L/R mono operation may be
used for mics and instruments or stereo for everything
else.
The connectors are wired as follows, according to
standards specified by the AES (Audio Engineering
Society).
Balanced 1/4" TRS
Hot (+)
Cold (–)
Shield (Ground)
Balanced 1/4" Connectors
Unbalanced 1/4" TS
Hot (+)
Shield (Ground)
Unbalanced 1/4" Connectors
NEVER connect the output of an amplifier
directly to a Big Knob's input jack. This
could damage the input circuitry and we
wouldn't want that now, would we?
Tip
Ring
Sleeve
RING SLEEVE SLEEVE RING TIP
TIP
RING
TIP
SLEEVE
Tip
Sleeve
SLEEVE SLEEVE TIP
TIP
TIP
SLEEVE