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16

15. Technical Specifications

Inputs

Switchable between two XLR-3 sockets and a

special input for the SCHOEPS KCY “active

cable.”

XLR inputs are balanced and transformerless; 

the 48 Volt phantom powering is switchable

(for subsequent M/S dematrixing).

Input impedance: 20 kOhm

Recommended min  imum sensitivity of micro-

phones at XLR inputs: 8 mV/Pa

Maximum input level for <0.5% THD: 

at 4 dB gain setting: 14 dBV (5V

rms

at 20 dB gain setting: -2.2 dBV (780 mV

rms

)

Preamplifier gain settings: 4, 10, 20, 30 or 40 dB

Overall performance specifications of VMS 5 U

with SCHOEPS CMC 64 (cardioid):

Equivalent noise level: 25,5 dB (CCIR, qps);  

15 dB (A-weighted)

Maximum sound pressure level:

(at 4 or 10 dB gain): limited by CMC micro-

phone amplifier to 132 dB

(at 20 dB gain): 130 dB

(at 30 dB gain): 120 dB

(at 40 dB gain): 109 dB

Level indicators: -20 dB, -3 dB

The “Balance” potentiometer permits compen-

sation for differences in microphone sensitivity.

A polarity inversion switch permits rapid change

of channel assignments in M/S recording.

Outputs

The outputs are impedance-balanced, 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 V

rms

)

Recommended load impedance: 2 kOhm or

greater

Headphone output

Switchable; either the amplified microphone sig-

nals (=left/right for A/B recordings, or mid/side

for M/S) or the de coded M/S stereo signals

can be monitored. 

Headphone impedance: 32 - 2,000 Ohms

Headphone socket: ¼” stereo phone jack

Filters

An infrasonic filter (20 Hz, 18 dB/oct.) is perma-

nently active. In addition, a low-cut filter 

(150 Hz, 6 dB/oct.) can be switched on.

The upper frequency limit is 80 kHz.

Powering

An internal filter/regulator circuit which gener-

ates and stabilizes the supply voltages permits a

wide range of input voltages (5.5 V to 15.5 V).

Operation with internal batteries

(possi-

bly rechargeable)

Number and type of cells: 6 x AA (also called

LR6)

Recommended primary cell type: Alkaline

Recommended rechargeable cell type: NiMH

A user-replaceable fuse protects against revers-

ing the polarity of the batteries. 

Battery life with alkaline cells: ca. 8.5 hours

Battery life with rechargeable batteries:

ca. 3 hours (700 mAh NiCd)

ca. 5 hours (1100 mAh NiMH)

ca. 5,5 hours (1300 mAh NiMH)

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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