YORKVILLE AP6020AP6020, Owner'S Manual

1

Introduction

Your new Yorkville AP6020 power amplifier is designed and built to provide years of trouble free performance. The AP6020 combines the field 

proven reliability of our Audiopro amplifiers with customer requested features such as switchable limiter, a Mono/Stereo/Bridge switch, and 

SPEAKON™ output connectors as well as binding posts.

The

 AP6020

weighs a comfortable but solid 64 pounds, fits into three rack spaces, and reproduces music with over 7000 Watts of head-

room. 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 that 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

AP6020

does exactly that.

Inputs

Balanced Inputs

Either 

XLR

 or two–circuit ‘

R

ing, 

T

ip, 

S

leeve’ 

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 con-

nected 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 effective-

ly 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 

R

ing terminal to the sleeve terminal, oth-

erwise 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 

AP6020

. 

Connect a bal-

anced cable to the 

AP6020

just as you would if you were running 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 con-

nection enables the 

AP6020

’s input to 

look

 down the cable 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 

AP6020

. 

Driving Multiple 

AP6020

’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. 

Ground Switch

Switching the ground switch on the rear panel will disconnect chas-

sis ground from circuit ground. Safety (

earth

) ground is still con-

nected to the chassis. We 

do not

 recommend lifting the ground strap 

unless you are experiencing problems with ground loop hum in mul-

tiple amplifier setups where lifting the ground straps of all but one 

a

mplifier cures the hum problem.

NOTE:

 These patch cords 

MUST

 be balanced whether the 

input signal is balanced or unbalanced!

CAUTION

: Sometimes hum problems are an indication of 

improper AC wiring somewhere else in your system. Don’t 

just doctor the symptom by lifting grounds. Fix the cause 

by making sure that the proper electrical wiring safety 

regulations have been adhered to.