using the hum eliminator™ hum eliminator - … · hum eliminator™ applications ... related hum...

Page 1

Hum

Elim

inato

r™ A

pplic

atio

ns

Hum

Elim

inato

r™ G

enera

l Instru

ctio

ns

The H

um

Elim

inato

r™ does m

ore

th

an ju

st

pre

vent

AC

hum

fro

m bein

g pic

ked up by your

sound

syste

ms. It a

lso c

an b

e u

sed a

s o

ne o

f the m

ost c

ost-e

ffectiv

e w

ays to

convert u

nbala

nced s

ignals

to tru

e

bala

nced s

ignals

.

GRO

UN

D L

OO

PS - T

he H

um

Elim

inato

r™ p

revents

gro

und lo

op a

nte

nnae fro

m fo

rmin

g a

nd p

ickin

g u

p A

C

hum

. AC

hum

& n

ois

e is

alm

ost a

lways c

aused b

y a

loop a

nte

nna e

ffect a

cro

ss s

ignal lin

es b

etw

een tw

o

or m

ore

pie

ces o

f gear, o

r by lo

ng u

nbala

nced c

able

s pic

kin

g u

p n

oise

. Loop a

nte

nna(e

) are

basic

ally

a ty

pe

of ra

dio

ante

nna, w

hic

h te

nd to

pic

k u

p th

e 6

0H

z and h

arm

onic

s (5

0H

z in o

ther p

arts

of th

e w

orld

) AC

sig

nal b

ein

g b

roadcast b

y a

build

ing's

ele

ctric

al c

urre

nt. T

hese lo

op a

nte

nnae a

re c

losed c

ircuits

usually

alo

ng th

e g

round w

ires a

nd h

ence a

re c

om

monly

calle

d g

round lo

ops.

BA

LA

NC

ED

/ UN

BA

LA

NC

ED

- Unbala

nced sig

nals a

re m

ore

susc

eptib

le to

pic

kin

g u

p e

lectric

al n

oise

& R

F

inte

rfere

nce th

an bala

nced sig

nals

are

. The lo

nger

the unbala

nced cable

, th

e gre

ate

r th

e chance of

a

pro

ble

m. T

he H

um

Elim

inato

r™ is

one o

f the m

ost c

ost-e

ffectiv

e w

ays to

convert b

etw

een u

nbala

nced

sig

nals

and tru

e b

ala

nced s

ignals

.

MIX

ERS/R

EC

ORD

ING

- Many m

ixers

have e

ither u

nbala

nced o

r "im

pedance b

ala

nced" m

onito

r outs /

aux se

nds. U

se a

Hum

Elim

inato

r™ to

get tru

e b

ala

nced m

onito

r outs fo

r noise

-free p

erfo

rmance. W

hen u

sin

g

more

than o

ne m

ixer (o

r subm

ixin

g), th

ere

's a

huge c

hance o

f gettin

g g

round lo

ops (a

nd th

at b

uzz!). U

se

Hum

Elim

inato

rs™ to

pre

vent th

ese

gro

und lo

ops. E

limin

atin

g h

um

is one o

f the b

iggest c

halle

nges fa

cin

g

stu

dio

s. M

any s

tudio

s w

ill run a

ll of th

eir lin

e le

vel g

ear th

rough H

um

Elim

inato

rs™ to

help

ensure

nois

e-

free re

cord

ing.

KEYBO

ARD

S / S

AM

PLERS / S

YN

TH

S · M

ost k

eyboard

s, sam

ple

rs, and sy

nth

esize

rs have u

nbala

nced -1

0dBV

outp

uts. U

se a

Hum

Elim

inato

r™ to

bala

nce th

e sig

nals if u

sing w

ith o

ther -1

0dBV

equip

ment. T

o u

se a

-10dBV

unbala

nced d

evic

e w

ith a

+4dBu b

ala

nced d

evic

e, u

se a

n E

BTEC

H® L

ine L

evel S

hifte

r™.

LIV

E S

OU

ND

/ DJ M

IXERS - A

com

mon p

roble

m w

ith liv

e p

erfo

rmance is

long u

nbala

nced c

able

s p

ickin

g

up hum

alo

ng th

e w

ay.

Bala

nced sig

nals

are

m

ore

im

mune to

pic

kin

g up nois

e.

Use th

e H

um

Elim

inato

r™ to

bala

nce lo

ng unbala

nced sig

nals.

Mobile

D

Js

or

bands

never

know

w

hen se

tting u

p th

eir

syste

m if th

ey're

goin

g to

get a

hum

or n

ot. T

he e

lectric

al w

iring c

hanges fro

m o

ne b

uild

ing to

anoth

er.

What

work

s fin

e at

one gig

m

ight

not

work

at

the next.

It's w

orth

th

e lo

w cost

to keep a H

um

Elim

inato

r™ a

vaila

ble

, nobody c

an a

fford

to lo

se a

gig

because

of h

um

pro

ble

ms. S

om

e D

Js ru

n e

very

thin

g

in th

eir

rig th

rough H

um

Elim

inato

rs to

pla

y it

safe

. The m

ain

outs

on m

ost

DJ m

ixers

are

-1

0dBV

unbala

nced R

CA

. When u

sin

g w

ith a

+4dBu p

ow

er a

mp, o

ver 2

/3rd

's o

f the a

mp's

volu

me c

an b

e lo

st.

Use a

n E

BTEC

H® L

ine L

evel S

hifte

r™.

PO

WER A

MPLIF

IERS - R

unnin

g m

ultip

le a

mplifie

rs c

an c

reate

gro

und lo

ops b

etw

een th

e a

mplifie

rs, w

hic

h

will p

ick u

p th

e d

readed h

um

and b

uzz. R

un e

ach a

mplifie

r's in

put lin

e th

rough a

Hum

Elim

inato

r™ to

pre

vent th

is p

roble

m.

GU

ITA

R O

R BA

SS -

Whenever

possib

le,

we re

com

mend you use our

Hum

X

pro

duct

for

GRO

UN

D

RELA

TED

hum

issues o

n a

guita

r or b

ass rig

setu

p. If y

our a

re in

apart o

f the w

orld

where

the H

um

X

cannot b

e u

sed, th

e H

um

Elim

inato

r is th

e n

ext b

est s

olu

tion. If a

ny o

f your F

X p

edals

have a

3 p

rong

gro

und p

ow

er p

lug, y

ou w

ill need to

put th

e H

um

Elim

inato

r on th

e a

udio

feed to

the a

mp. W

hen u

sing

two o

r more

guita

r am

plifie

rs (with

stere

o F

X o

r ABY sp

litters), g

round lo

ops c

an fo

rm b

etw

een th

e a

mplifie

rs. Bass a

mps c

an g

et g

round lo

op fro

m th

e D

I connectio

n to

the P

A; sim

ply

run th

at D

I feed th

rough th

e H

um

Elim

inato

r.

CO

MPU

TER S

OU

ND

CA

RD

S - M

ost so

und c

ard

s have u

nbala

nced in

puts a

nd o

utp

uts. B

ala

nce th

ese

with

the

Hum

Elim

inato

r™. E

ven b

ala

nced so

und c

ard

s have tre

mendous su

sceptib

ility to

gro

und lo

ops b

ecause o

f the

com

pute

r's p

ow

er s

upply

. If you h

ear a

buzz, u

se a

Hum

Elim

inato

r™.

BRO

AD

CA

STIN

G / V

IDEO

- Pre

ss Boxes h

ave m

any fe

eds a

ll goin

g to

diffe

rent g

ear; w

hic

h c

an c

reate

lots o

f gro

und lo

ops

and hum

. U

se a H

um

Elim

inato

r™ on th

ese

fe

eds

to elim

inate

th

e pro

ble

m.

Usin

g a H

um

Elim

inato

r™ o

n th

e a

udio

feed o

f a v

ideo c

am

era

can h

elp

pre

vent v

ideo h

um

(snow

).

Rev. J

un 1

9, 2

012

WH

AT W

ILL T

HE H

UM

ELIM

INA

TO

R™

SO

LV

E?

The H

um

Elim

inato

r™ is

a unity

gain

sig

nal

and gro

und path

is

ola

tor

desig

ned to

bre

ak g

round lo

ops. H

um

and n

ois

e c

aused b

y th

e p

resence o

f a g

round lo

op c

an b

e

sto

pped b

y in

sertin

g th

e H

um

Elim

inato

r™ in

the lin

e le

vel s

ignal p

ath

(+4dBu o

r -10dBV

). This

elim

inate

s th

e g

round lo

op w

ithout d

egra

din

g y

our s

ignal. T

he H

um

Elim

inato

r™

will n

ot re

duce h

um

or n

ois

e n

orm

ally

genera

ted b

y a

pie

ce o

f equip

ment. In

oth

er

word

s, fo

r nois

y p

ream

ps, n

ois

y s

ingle

coil p

ickups o

r nois

e c

aused b

y fa

ulty

tubes,

oth

er c

orre

ctiv

e a

ctio

n w

ould

apply

.

USIN

G T

HE H

UM

ELIM

INA

TO

R™

Identify

the g

round lo

op c

ausin

g th

e tro

uble

; not a

ll gro

und lo

ops c

ause n

ois

e o

r hum

. For c

om

ple

x s

yste

ms y

ou m

ay n

eed to

repeat th

ese s

teps s

tartin

g w

ith a

diffe

rent

pie

ce o

f equip

ment in

vario

us c

om

bin

atio

ns to

locate

the p

roble

m:

1)

Strip

th

e syste

m dow

n to

one pie

ce,

such as th

e m

ixer,

by dis

connectin

g all

inte

rconnects

and A

C c

ord

s e

xcept fo

r the m

ixer.

2)

Add one pie

ce of

equip

ment

at

a tim

e;

hook up A

C and in

terc

onnects

(m

akin

g

sure

all g

rounds a

re c

onnecte

d a

nd in

good c

onditio

n) th

en lis

ten fo

r hum

or n

ois

e.

3) T

urn

on a

nd o

ff the p

ow

er e

ach tim

e y

ou s

witc

h e

quip

ment to

avoid

pops/s

horte

d

outp

uts

.4) P

roceed u

ntil y

ou fin

d th

e o

ffendin

g p

iece(s

) causin

g th

e p

roble

m.

5)

Plu

g th

e H

um

Elim

inato

r™ in

all

lines betw

een th

e offe

ndin

g equip

ment

and th

e

rest o

f the s

yste

m. F

or e

xam

ple

, insert th

e lin

e o

uts

of th

e k

eyboard

into

the in

puts

of th

e H

um

Elim

inato

r™, th

en in

sert th

e lin

e o

uts

of th

e H

um

Elim

inato

r™ in

to th

e in

puts

of th

e m

ixer.

IMPO

RTA

NT:

Never

use th

e H

um

Elim

inato

r™ betw

een an am

plifie

r and speaker

or

the equip

ment

may becom

e dam

aged.

Use only

on non-p

ow

ere

d lin

e le

vel

sig

nals

.

With

a ra

ck o

f am

plifie

rs, w

e re

com

mend p

uttin

g a

n 8

channel s

ingle

rack s

pace

Hum

Elim

inato

r™ in

front o

f your a

mps' in

puts

so y

ou d

o n

ot h

ave to

solv

e g

round lo

op

pro

ble

ms d

urin

g s

ound c

hecks.

A com

mon path

fo

r gro

und lo

ops is

th

rough a chassis

in

to th

e ra

ck and th

en in

to

anoth

er

chassis

. Test

this

by re

movin

g th

e chassis

fro

m th

e ra

ck.

The H

um

Elim

inato

r™ w

ill help

but y

ou s

hould

als

o try

isola

ting th

e c

hassis

from

the ra

ck w

ith

ele

ctric

al ta

pe a

nd in

sula

ting th

e ra

ck s

cre

ws w

ith n

ylo

n w

ashers

.

Most

gro

und lo

op pro

ble

ms can be solv

ed usin

g th

e H

um

Elim

inato

r™.

Patie

nce is

a

necessity

w

hen atte

mptin

g to

solv

e gro

und lo

ops!

Many popula

r m

ixers

w

ith TRS

bala

nced lin

e in

puts

do not

have com

mon m

ode re

jectio

n.

They dro

p th

e in

verte

d

sig

nal,

cre

atin

g unbala

nced in

puts

! To get

the benefits

of

bala

nced in

puts

, ru

n your

bala

nced lin

e in

to th

e H

um

Elim

inato

r™ a

nd ru

n a

mono 1

/4" lin

e fro

m th

e H

um

Elim

inato

r outp

uts

to th

e m

ixer's

TRS in

puts

. This

way y

ou are

ru

nnin

g a bala

nced lin

e all

the

way u

p to

the H

um

Elim

inato

r™ a

nd y

ou w

ill not lo

se c

om

mon m

ode re

jectio

n.