Sennheiser MKH 415 Instructions for Use - Page 9

Co

of the

Sennheiser

condenser

microphones

with A-B powering

is so low (approx.

20 Q)

that an amplifier

input with an impedance

oI

at least

200 Q will be suitable.

Sennheiser

condenser

microphones

pro-

duce

relatively

large

output

voltages,

these

can

be

up to

1 volt

with

maximum

sound

pressure

levels. This has the advantage

that

even

with long cables

induced

interference

signals

can be disregarded.

Also the internal

noise

produced

by the microphone

does

not

contribute

to the

total

noise

level. The

mi-

crophones

are

fitted

with

high

frequency

filters,

which ensure

that

no high frequency

signals

from the

microphone

can

affect

the

external

circuitry,

and

also

that

the

micro-

,.

'

.

one itself isprotected

from high frequency

~turbance.

It is, therefore,

not necessary,

even

under

the

most difficult

conditions,

to

take

special

precautions

such

as

double

screening

of the

cables

or the

provision

of

high

frequency

filters.

Sennheiser

condenser

microphones

are po-

larised

according

to DIN standard

i.e. when

apressure

signal

strikes

the

capsule

from

the front, Pin 1 goes

positive

with reference

to

Pin 3. This

snould

be

considered

when

the

amplifier

input plug

is being

wired.

Connection

to Amplifiers with Symmetrical

Inputs

In this

case

the

microphone

is simply

con-

nected

to

the

input

of

an

amplifier

via

a

battery

adapter

or the power supply MZN 5-1.

For

larger

installations

the

power

supply

MZN 6, which

can

feed

up

to

six

micro-

phon es,

can

be

used.

It should

be

noted

that

this

power

supply

is delivered

without

feed

resistors

and these

must be added

by

the

user.

Connection

to Amplifiers

with

Unsymmetrical

Inputs

In many

cases,

for

example

most

tape

re-

corders,

the

input

socket

is unsymmetrical.

In this

case

one

side

of the

symmetrical

microphone

output

has to be earthed.

Apart

from

cases

where

the

microphone

is being

used

for

professional

studio

purposes,

this

is not critical,

as the

large

output

voltage

of

the

microphone

combined

with

its low out-

put

impedance

provides

a large

signal

to

noise

ratio. Care

should

be taken,

however,

9

Sennheiser MKH 415 Instructions for Use - Page 9

Connection, to Amplifiers with Symmetrical, Inputs

Page 9 highlights