Balanced Inputs; Unbalanced Inputs - YORKVILLE AP2020 Owner's Manual

INTRODUCTION
Your new Yorkville AP2020 AP2020 power amplifier is designed and built to provide years of trouble free
AP2020 AP2020
performance. The AP2020 AP2020 combines the field proven reliability of our Audiopro amplifiers with customer
AP2020 AP2020
requested features such as switchable limiters, a Mono/Stereo/Bridge switch, and SPEAKON™ output
connectors as well as binding posts.
The AP2020 AP2020 weighs a comfortable but solid 35 pounds, fits into two rack spaces, and reproduces music with over
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2000 Watts of headroom. It will drive reactive phase shifted loads with no difficulty - even though it is fully protected from
accidental short circuits. Our design goal was to create an amplifier which would do exactly what an amplifier should do:
reproduce music with great power, complete reliability, and uncompromising signal fidelity. We think you will agree that
the Yorkville AP2020 AP2020 AP2020 does exactly that. AP2020
INPUTS

Balanced Inputs

Either XLR or two–circuit 'Ring, Tip, Sleeve'
Stereo 1/4" PHONE cords may be used. Each
channel's XLR input is internally paralleled
with its phone input (The TIP of the channel
'A' PHONE input is connected to pin 2 of its
XLR input, the RING is connected to pin 3,
and the Sleeve is connected to PIN 1). PIN 2
is in phase, PIN 3 is 180 degrees out of phase,
and PIN 1 is ground. We recommend using
balanced lines for the best hum-free
performance, particularly when chaining
multiple amplifiers.

Unbalanced Inputs

Ordinary single circuit Standard 1/4" PHONE plugs
may be used to connect unbalanced signals.
IMPORTANT NOTE: Such plugs effectively connect the
ring terminal to sleeve ground, so they work correctly.
However, if you use a Stereo 1/4" PHONE plug on an
unbalanced line, you MUST short the Ring terminal to
the sleeve terminal, otherwise the sensitivity will be 6dB
lower than is specified! (The same applies to the XLR
input: To connect an unbalanced source via the XLR
input, you must connect the signal to Pin 2 and ground
BOTH Pin 1 and Pin 3).
Remote Referencing
You can approach balanced performance with
unbalanced sources by utilizing the remote reference
feature of the AP2020 AP2020. Connect a balanced cable AP2020 AP2020
to the AP2020 AP2020 just as you would if you were running
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a balanced line. At the other end, connect Pin 3 and Pin
1 together, (or connect ring to sleeve if you are using a
PHONE plug cable), and plug this modified end into
your unbalanced piece of equipment. This connection
enables the AP2020 AP2020 AP2020's input to look down the cable AP2020
directly at the output jack of the unbalanced equipment.
Any hum voltage generated across the cable's
impedance will be attenuated by the common mode
rejection of the AP2020 AP2020 AP2020. AP2020
Driving Multiple AP2020's
In large installations it is often desirable to operate
many amplifiers in tandem. Since each channel's XLR
input is internally paralleled with its phone input, you
may use the remaining input jack as an output to the
next amplifier. Obviously you will need both XLR to
XLR and PHONE to PHONE patch cords if you are
going to tandem more than two amplifiers.
NOTE: These patch cords MUST be balanced
whether the input signal is balanced or unbalanced!
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