2882 Users Guide
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wide range of matching impedances. This means that Mobile I/O handles sources from mic level to line
level and from mic impedance to guitar impedance. With that in mind, there are a number of aspects of
the design that you should take into account when interfacing with Mobile I/O.
Whenever possible, use balanced interconnects with Mobile I/O. The performance of balanced intercon-
nects is much higher and much more resistant to noise interference and electrical (power) wiring problems.
The expense of balanced interconnects is not substantially higher than unbalanced connections, so if the
gear that you are interfacing with supports balanced connection — use it. If you cannot utilize balanced
interconnects, there are connection schemes that you can use that will maximize performance.
On input, at line level, it is sufficient to simply use standard unbalanced (TS) connections. If you are inter-
facing with the Mobile I/O XLR inputs, you will need to ensure that pin 3 is grounded in the unbalanced
adapter cable. More information about adjusting the input level can be found in the MIOConsole3d soft-
ware chapter.
The Mobile I/O XLR inputs are all wired pin 2 hot and the 1/4” inputs are wired Tip hot.
TIP:
To use the 2882 TRS input with guitar or bass, you can simply use a standard TS guitar cable
(patch cord) and it will work fine. However, you can take advantage of the balanced input design
of the 2882 to get more noise rejection than you thought possible on a guitar input.
In order to do this, you will need to make a pseudo-balanced telescoping shield guitar cable.
This can be constructed with a TRS connector, a TS connector and balanced microphone cable.
This cable will treat the guitar as a floating balanced source and provide a telescoping shield
from the 2882 ground.
Sleeve (Shield)
Tip (Hot)
Ring (Cold)
Tip
Sleeve
Instrument
Mobile I/O
Sleeve Ring Tip
Figure 8.7: Telescoping Shield Cable for Instruments
If you want to use the TRS inputs with balanced microphones, you will need an XLR female to 1/4” TRS
balanced plug adapter cable. These are available commercially, or you can construct one easily. The con-
nections are Tip to Pin 2, Ring to Pin 3 and Sleeve to Pin 1:
1
2
3
Tip
Ring
Sleeve
Sleeve Ring Tip
XLR CONNECTOR MALE OR FEMALE
BALANCED TRS 1/4" CONNECTOR
Figure 8.8: XLR to Balanced TRS Cable
On output, the situation is a bit more complex. If you are driving an unbalanced load, you will get the best
performance by not connecting the ring of the TRS jack to ground. In order to do this, you can simply use
