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6

not, the batteries need to be changed,
or recharged if they are NiCd/NiMH
types. When running on internal bat-
teries, the borderline between the red
and green zones is at about 7 Volts; at
this level the “LOW BAT” LED begins to
flash. With high-capacity rechargeable
batteries (1300 mAh) there should be
approximately a 10-minute interval
before the unit shuts itself off automat-
ically.

External powering

When the unit is externally powered

(and only then!) it is acceptable if the
battery indicator <12> is in the red
zone. It is calibrated for internal battery
powering, and its reading will be offset
slightly when external powering is used:
the boundary between red and green
will be at 7.5 Volts while the far end
of the green region will be at 10 Volts.
When the indicator is near the left end
of the red region the unit will no longer
function.

The “LOW BAT” LED <13> will begin

to blink at around 7,5 Volts, but can
be ignored with external powering.

3. Automatic shutoff

The unit will turn itself off if the volt-

age of the internal batteries falls beneath
the limit of proper functioning. This
avoids overly deep discharge of the
batteries, which could otherwise lead
to chemical leakage or, in the case of
rechargeable batteries, life-shortening

damage and possible cell reversal.

To turn the unit back on after an

automatic shutoff, turn the power
switch off and then on again, and/or
replace the batteries as needed.

When the unit is powered externally,

the automatic shutoff circuit is dis-
abled so that a brief interruption in
external power will not cause a pro-
longed shutdown in the absence of
internal batteries. However, a minimum
of 5.2 Volts (externally) must be sup-
plied for the unit to continue operating.

4. External powering

The VMS 5 U can be powered by

external batteries or AC power adap -
ters through a socket on the back of
the unit. The 5.5 mm/2.1 mm coaxial
power plug is a commonly available
part, and is found on AC power adap -
ters of many kinds. 

We generally recommend using the

SCHOEPS mains adapter VMS 5 DC. If
another type or external batteries are
used, please note the following hints:

The voltage at the socket may be

anywhere between 5.5 and 15.5 Volts
DC.
Recommendation: voltage and current
(approximate):

6 V, 500 mA
8 V, 400 mA
9 V, 350 mA

10 V, 300 mA
12 V, 300 mA
15 V, 250 mA

Содержание VMS 5 U

Страница 1: ...VMS 5 U User s Manual Microphone preamplifier with phantom powering M S matrix and headphone output with special input for Schoeps active Y cable...

Страница 2: ...ts 18 Input for external power supply 19 Input selector switch The connectors and labels on the rear of the VMS 5 U are upside down with respect to the front of the unit This simplifies its use since...

Страница 3: ...3 15 16 19 17 18 8 9 10 11 12 13 14 1 2 3 6 7 4 5...

Страница 4: ...tweight robust all metal housing 1 Inserting batteries The VMS 5 U operates from six AA LR 6 cells included Primary cells preferably alkaline can be used or rechargeables such as NiCd or NiMH To inser...

Страница 5: ...echarge ables should all be of the same type and capacity as one another all batter ies should be changed and or charged together as a set This is to avoid the risk of one or more cells those of lower...

Страница 6: ...neath the limit of proper functioning This avoids overly deep discharge of the batteries which could otherwise lead to chemical leakage or in the case of rechargeable batteries life shortening damage...

Страница 7: ...ble batteries Note the polarity of the DC power connector the positive pole of the power supply must be connected to the center contact of the external powering socket 18 on page 3 The unit will not b...

Страница 8: ...your headphones temporarily 8 Connecting 48 Volt phantom pow ered studio condenser microphones For the highest quality lowest noise recordings use condenser microphones with a sensitivity of at least...

Страница 9: ...ed only when needed since it has a distinctly audible effect position Now you can turn the unit on For ordinary stereo recordings not M S the cable marked in red should carry the right channel signal...

Страница 10: ...ible rejection of hum and radio frequency interference Not all recorders offer balanced inputs but with short cables less than a few meters this is generally not so critical If you need to connect the...

Страница 11: ...cording techniques A B X Y ORTF Blumlein etc two micro phones are used of which one the side or S channel must have a figure 8 directional pattern the other microphone the mid or M chan nel may have a...

Страница 12: ...ll become narrower Any sound sources located beyond that angle near the edges will be picked up out of phase and will seem to jump over to the channel opposite from where they were in reality The opti...

Страница 13: ...eard in a steadily decreasing degree in the left channel output signal But if that sound source crosses past the null in the polar diagram of the left channel virtual microphone see above its presence...

Страница 14: ...1 M MK4 CCM 4 Effect of the WIDTH control on the recording angle for various types of M channel microphones Effect of the WIDTH control on the gain applied to M and S signals S M M M S S 0 1 2 3 4 5 6...

Страница 15: ...find an optimal setting for the stereo image width as it would be reproduced through loudspeakers In addition to experimenting with various width settings it can some times be very useful to equalize...

Страница 16: ...alanced trans formerless and are switchable between the amplified microphone signals and the decoded M S stereo signals Output impedance 100 Ohm Maximum output level for 0 5 THD 18 dBV 8 Vrms Recommen...

Страница 17: ...ll blow See page 7 Coaxial socket 5 5 2 1 mm diameter Reverse polarity will not damage the unit though it will not operate If external powering is present any internal bat teries are automatically dis...

Страница 18: ...18 16 Block diagram...

Страница 19: ...19 Frequency response curves above without low cut filter below with low cut filter...

Страница 20: ...0 C to 50 C The headphone volume levels which can be achieved with this unit can with prolonged use cause lasting damage to one s hearing Please monitor only at the minimum necessary levels Cables Use...

Страница 21: ...to misuse e g incorrect operation mechanical damage abuse or acts of God This guarantee is nullified in the event of tampering by unauthorized persons or agencies To secure your rights under this guar...

Страница 22: ...22...

Страница 23: ...23...

Страница 24: ...24 Subject to change without notice 010102...

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