DYNACO Stereo 70 Instruções de montagem - Página 10

Procurar online ou descarregar pdf Instruções de montagem para Amplificador DYNACO Stereo 70. DYNACO Stereo 70 16 páginas. Series ii tube amplifier
Também para DYNACO Stereo 70: Manual de Restauro (20 páginas), Manual de Restauro (5 páginas), Manual do Proprietário (12 páginas)

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modate Dynakit monophonic preamplifiers without

modification.

The stereo 70 can be turned on and off from

the back panel switch, or this switch can be left in

"on" position, and the amplifier switched from one

of the switched ac outlets on the associated pre-

amplifier.

High-Low frequency amplification

For this type of operation the input switch on

the Stereo 70 should be put to "stereo" position.

The low frequency output of the dividing or cross-

over network should be fed to the left input, and

the "left" loudspeaker output should be connected

to the bass speaker. The high frequency output of

the diViding or cross -over network should be fed

through the right channel, and the tweeter con-

nected to the "right" loudspeaker terminal strip.

Monophonic 70 watt amplification

For monophonic operation, the two channels

the Stereo 70 may be paralleled. For this, only

one input cable is connected to either the left or the

right input (but not both), the input s witch is set to

"mono", and the outputs are connected together.

insulated wire jumper should be connected from

"c"

on the screw terminal strips. Another

insulated wire jumper should be connected from

"8" to "8"

a 4 ohm loudspeaker is used, or from

"16" to" 16" is an 8 ohm or 16 ohm loudspeaker is

used. When using the 16 ohm loudspeaker in this

fashion, the amplifier's maximum power output is

not as great because of the impedance. mismatch,

but there is no loss of power when using a 4 ohm

or 8 ohm loudspeaker as specified above. The

maximum power available into a 16 ohm loudspeaker

is still 55 watts, however, and there is a compen-

sating factor. The distortion, as levels below max-

imum, will be reduced by this type of connection.

What happens is that the operating conditions are

shifted from maximum power output to minimum

distortion.

This same operation can also be

achieved, of course, by connecting an 8 ohm loud-

speaker to paralleled 8 ohm taps, or a 4 ohm

loudspeaker to paralleled 4 ohm taps. Note that

whenever the two outputs are paralleled, only one

input cable should be used, the other input socket

should not be used, and the switch is on "mono".

also practical to use the "mono" position

with a single input source with two separate loud-

speakers.

this case, each speaker is connected

to one of the screw output strips using the imped-

ance which pertains to the respective speaker. No

jumpers are required between the output strips.

A monophonic preamplifier wh i c h requires

power from the amp 1

ie r can be connected to

either of the two power takeoff sockets.

ENJOYING STEREOPHONIC SOUND

S tel' e

n i c sound

e r s an important

enhancement of enjoyment of your high fidelity

system. The proper setup and use of your stereo-

phonic system will bring considerable satisfaction.

However, stereophony introduces problems in high

fidelity reproduction which can dim in ish your

enjoyment of your hi

system unless these prob-

lems are understood and corrected.

These few

notes on the subject should assist materially in the

installation and use of a stereophonic system which

adds to your listening pleasure.

The pieces of equipment to be used should be

as similar as possible in each channel.

This is

particularly true for the loudspeaker to be used.

Different types and brands of speakers have very

great differences in frequency response and other

important characteristics.

If,

for example, one

speaker has a peak in response at a certain fre-

quency where the other does not, the stereophonic

balance will be changed at that frequency.

The

need for frequent rebalancing is due to this type

of dissimilarity.

There has been a relatively high proportion of

dissatisfaction with stereo which has arisen be-

cause of the attempt to attach an inferior second

channel to complete a system.

this channel

differs from the first channel it frequently destroys

any potential benefits of stereophonic sound.

The proper reproduction of monophonic discs

through the stereo system requires the cancella-

tion of identical signals (of opposite phase) so that

there is no unwanted vertical signal component in

the output.

This requires either the parallelling

of the two sides of the cartridge or the parallelling

of the outputs of identical preamps.

the preamps

are slightly different, the vert i cal components

cannot be eliminated properly.

Dynakit pre-

amplifiers, the critical components which deter-

mine the response characteristics of the preamp-

lifier playback characteristics have a tolerance

of only 1

so that this pro b I e m cannot cause

difficulty.

Channel phasing is a problem of stereo which

is readily solved, once understood.

If,

on a single

sound, one speaker cone moves inward while the

other moves out, the s y s t em is not properly

phased, and the sound area between the speakers

will lack homogeneity. All tapes and all discs are

now reproduced so that their phasing is consistent.

Therefore, once phasing of the playback equipment

is set it can be maintained for all tape and disc

sources without further change.

To check for proper phasing, playa monophonic

recording so that one signal comes through both

channels. Then move back and forth between the

speakers.

phasing is correct, there will be a