VMS 5 UUser’s Manual

Microphone preamplifier with phantom powering,

M/S matrix and headphone output,

with special input for Schoeps active Y-cable

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Control layouts:

Front:

<1> Signal level indicators<2> Preamp gain control<3> Left/Right balance control<4> Switch for low-cut filter<5> Channel assignment switch (for

M/S)<6> Stereo width control (for M/S)<7> Main output selector<8> Headphone jack<9> Headphone output selector

<10> Headphone level control<11> Phantom power switch<12> Battery level meter<13> External power indicator (yellow);

low-battery warning (red)<14> On/Off switch

Rear, as seen from above*:

<15> Input for SCHOEPS active Y-cable<16> Balanced XLR microphone inputs <17> Balanced XLR line outputs<18> Input for external power supply<19> Input selector switch

* The connectors and labels on the rearof the VMS 5 U are “upside-down”with respect to the front of the unit.This simplifies its use, since the unitdoes not need to be turned aroundsideways to read the labels.

Table of contents

1. Inserting batteries . . . . . . . .42. Battery level meter . . . . . . . .53. Automatic shutoff . . . . . . . .64. External powering . . . . . . . .65. Connecting microphones . . .86. Setting the preamp gain . . .97. Balance setting . . . . . . . . . .98. Signal level indicators . . . . .99. Low-cut filter . . . . . . . . . . . .9

10. Connecting the outputs . . .1011. Connecting headphones . .1112. M/S recording/WIDTH . . . .1113. M/S dematrixing . . . . . . . .1514. M/S side inversion switch .1515 Technical specifications . . . .1616. Block diagram . . . . . . . . . .1817. Important information . . . .2018. Warranty . . . . . . . . . . . . . .21

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<15> <16>

<19>

<17> <18>

<8> <9> <10> <11> <12> <13> <14>

<1> <2> <3> <6> <7><4> <5>

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The VMS 5 U is designed for indoorand outdoor professional recordingapplications. Its features include:

– 48 Volt phantom powering– Special input for SCHOEPS active

Y-cable– Switchable M/S matrix– Frequency range: 20 Hz - 80 kHz

(-3 dB)– Headphone output, switchable

(before or after the M/S matrix)– Can be operated from internal bat-

teries or external power– Automatic “glitch-free” switchover

to battery powering if the AC supplyis interrupted

– Rechargeable batteries are automati-cally protected from extreme dis-charge

– Durable, high-quality switches andconnectors (gold-plated contacts)

– Lightweight, 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, orrechargeables such as NiCd or NiMH.

To insert batteries, turn the unit offand open the battery compartment onthe underside by turning the slottedbutton in the lid (perhaps with the aidof a coin) one quarter turn in eitherdirection.

Please note:The orientation of the batteries is

shown on the battery holders:

All batteries must go in thesame direction!

Make sure that the battery contactsare kept clean. If necessary, clean thecontacts with a pencil eraser.

After inserting batteries, close thebattery compartment lid and lock it byturning the slotted button a quarterturn in either direction until it clicksinto place.

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When the unit is first turned on, therewill be a four- to five-second delaybefore it is ready for use. This is neces-sary so that the unit can function reli-ably even with relatively low-poweredAC supplies.

Watch the battery level with specialcare when using rechargeable batteries;as they lose their charge, their voltagewill often drop off quite rapidly.

What happens if …… a battery is inserted the wrong

way? The resulting voltage will be toolow to operate the unit. If several bat-teries (cells) are put in backwards, aninternal fuse may burn out and needreplacing. An emergency replacementis provided within the unit. Both fuses(designated “2A F”) are accessiblewithin the battery compartment byusing a pair of regular pliers; see thediagram on the lid of the battery com-partment.

We recommend using alkaline bat-teries because they have the greatestcapacity and the longest shelf life.Zinc-carbon batteries and rechargeablebatteries (NiCd or NiMH) will not powerthe unit for as long a time (see “Speci -fications” at the end of this manual).

We strongly advise against mixingdifferent types of batteries or batteriesof differing “ages” together. Recharge -ables should all be of the same typeand capacity as one another; all batter-ies should be changed and/or chargedtogether as a set. This is to avoid the

risk of one or more cells (those oflower capacity) being too deeply dis-charged; even “sealed” alkaline cellscan leak corrosive chemicals, whilerechargeable bat teries can undergovoltage reversal and be permanentlydamaged. Further, operation timewould be reduced unnecessarily.

Though it may seem obvious thatonly new batteries in good conditionshould be used, we are obliged towarn against the use of weak or dam-aged batteries, to avoid harming thecircuitry of the VMS 5 U.

What should be done if the unitdoes not work with a new set ofbatteries? Turn the unit off, then waithalf a second and turn it back on.

If the “LOW BAT.” LED lights brieflybut then goes out, the batteries aresimply too weak; the charge is enoughto turn the unit on initially, but thenan automatic shutoff takes effect.

Please note: If the unit is not usedfor a prolonged period, the batteriesshould be removed to prevent possibledamage by leaking.

2. Battery level meter / LOW BAT

Powering with internal batteries / rechargeables

The battery level meter (<12> in thephoto on page 3) shows the state ofthe internal batteries. At the start of arecording the needle should always bein the green zone of the meter. If it is

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not, the batteries need to be changed,or recharged if they are NiCd/NiMHtypes. When running on internal bat-teries, the borderline between the redand green zones is at about 7 Volts; atthis level the “LOW BAT” LED begins toflash. With high-capacity rechargeablebatteries (1300 mAh) there should beapproximately a 10-minute intervalbefore the unit shuts itself off automat-ically.

External poweringWhen the unit is externally powered

(and only then!) it is acceptable if thebattery indicator <12> is in the redzone. It is calibrated for internal batterypowering, and its reading will be offsetslightly when external powering is used:the boundary between red and greenwill be at 7.5 Volts while the far endof the green region will be at 10 Volts.When the indicator is near the left endof the red region the unit will no longerfunction.

The “LOW BAT” LED <13> will beginto blink at around 7,5 Volts, but canbe ignored with external powering.

3. Automatic shutoff

The unit will turn itself off if the volt-age of the internal batteries falls beneaththe limit of proper functioning. Thisavoids overly deep discharge of thebatteries, which could otherwise leadto chemical leakage or, in the case ofrechargeable batteries, life-shortening

damage and possible cell reversal.To turn the unit back on after an

automatic shutoff, turn the powerswitch off and then on again, and/orreplace the batteries as needed.

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

4. External powering

The VMS 5 U can be powered byexternal batteries or AC power adap -ters through a socket on the back ofthe unit. The 5.5 mm/2.1 mm coaxialpower plug is a commonly availablepart, and is found on AC power adap -ters of many kinds.

We generally recommend using theSCHOEPS mains adapter VMS 5 DC. Ifanother type or external batteries areused, please note the following hints:

The voltage at the socket may beanywhere between 5.5 and 15.5 VoltsDC.Recommendation: voltage and current(approximate):

6 V, 500 mA8 V, 400 mA9 V, 350 mA

10 V, 300 mA12 V, 300 mA15 V, 250 mA

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0.5 A fast-blow fuse will burn out. It isaccessible through the battery com-partment; a spare fuse is providedwithin the unit. The locations of boththe actual and the spare fuse are shownin the drawing on the inside of the bat-tery compartment lid. A pair of regularpliers (not "needle-nose") can be usedto facilitate changing the fuse.

By maintaining separate grounds foraudio signals and for powering, thesupply regulation circuitry of the VMS 5 U permits the sharing of a com-mon power source with other equip-ment, without the risk of ground loops.

Notes on operation with an ACpower supply

Any AC power supply that will deliverat least 7 V at 500 mA in actual useand an open-circuit voltage of no morethan 16 V will be suitable. For exam-ple, the SCHOEPS AC power supplyVMS 5 DC (input = 230 VAC, equippedwith "Euro plug") delivers a stabilized12 Volts DC.

Please note: Different countries usedifferent AC voltages. Always makesure that your power supply is appro-priate for the AC voltage where you are.

Notes on operation with exter-nal batteries

The batteries should have a nominalvoltage of 6 to 12 Volts and a capacityof at least 500 mAh. A 6-Volt set ofgelled lead-acid rechargeable batteries

Note the polarity of the DC powerconnector: the positive pole of thepower supply must be connected tothe center contact of the externalpowering socket (<18> on page 3).The unit will not be harmed by reversepolarity, but will not operate; a protec-tive diode will prevent current fromflowing.

If a sufficient external DC voltage isconnected to the external poweringsocket of the unit, the "EXT" LED (<13>on page 3) will light, even if the unit isturned off; it is strictly an indication ofavailable powering, not of the unit’son/off status. In this mode of opera-tion, any batteries inside the unit willneither be charged nor discharged.

If for any reason the external power-ing should drop below the minimumrequired voltage (e.g. loss or reductionof AC power), the unit will immediatelyswitch over to battery power, assum-ing of course that batteries of sufficientvoltage are in the unit; the yellow LEDwill then go out. This automatic switch-over will occur without any disturbancein the audio signal.

The “LOW BAT” LED <13> will blinkwhen the input voltage is less than orequal to about 7.5 Volts, but this canbe ignored unless the battery indicatoris at the low end of the red region.

The meter is calibrated with referenceto internal batteries and will “under-read”slightly with external power sources.

If too high a voltage is applied to theexternal powering socket, the internal

with a capacity of 3.5 Ah can powerthe VMS 5 U for about 12 hours.

9-Volt transistor radio-type batterieshave excessive internal resistance andinsufficient capacity; they cannot beused.

Please note: When running onexternal batteries, during any longerpauses (or at the end of a recording)the unit should be switched off andthe external batteries disconnected.Simply turning the unit off would notprevent draining the external batteries,since a residual current of about 40mA is drawn from any external powersource. And disconnecting the externalpower connector without switchingthe unit off would cause a switchoverto any internal batteries, drawing thefull operating current from them.

5. Connecting microphones

The VMS 5 U can be used with 48Volt phantom powered microphonesor with microphone capsules and theactive Y-cable of the SCHOEPS"Colette" series. A switch (<19> onpage 3) on the back of the unit selectsone of these two types of inputs.

If the setting of this switch must bechanged while the unit is in use, pleaselower the headphone volume level orremove your headphones temporarily.

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Connecting 48-Volt phantom pow-ered studio condenser microphones

For the highest-quality, lowest-noiserecordings, use condenser microphoneswith a sensitivity of at least 8 mV/Pa.

Turn the unit off and connect themicrophones to the inputs (<16> onpage 3) on the back of the unit. Theinput selector switch <19> must be inits downward position (pointing to thewords "Made in Germany"). The "P48"switch <11> must be in the "ON" posi-tion for phantom powered microphones.Then the unit can be powered on.

For ordinary stereo recordings (notM/S), channel I is usually the left chan-nel while channel II is usually the right.For M/S recordings, the "mid" micro-phone (e.g. a forward-facing cardioidor supercardioid) should be connectedto channel I, while the "side" (figure-8)microphone should connected tochannel II.

Connecting SCHOEPS micro-phones with an active Y cable

If the recording environment is rela-tively free of interfering signals, it isalso possible to use an unbalancedcable such as the SCHOEPS KCY 250/5I. An input for this type ofcable is available on the back of theunit <15>.

To use this input, turn the unit off,attach the cable to the VMS 5 U andattach two SCHOEPS Colette-seriescapsules to the cable. The input selec-tor switch <19> must be in the "KCY"

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control should normally remain at itscenter detent setting.

In M/S recording, the Balance settingcontrols the ratio of mid to side signaland thus will affect the stereo imagewidth and the maximum recordingangle.

8. Signal level indicators

The two LEDs <1> serve as a roughindication of signal levels; they alwaysindicate the higher level of the twochannels. The yellow LED can andshould be lit very frequently, but if thered LED is lit at all it should be seldomand only quite briefly.

9. Low-cut filter

A 20 Hz high-pass filter with a slopeof 18 dB/octave is active at all times. Itsuppresses infrasonic interference, butis otherwise nearly inaudible in itseffect.

An additional, "soft" low-cut filter(150 Hz, 6 dB/octave) can be activatedby switching the "FILTER" toggleswitch to the down position, in orderto reduce wind and solid-borne noiseeven further, or to compensate for thebass boost which directional micro-phones exhibit when used close tosound sources ("proximity effect"). Butthis filter should be used only whenneeded since it has a distinctly audibleeffect.

position. Now you can turn the unit on.For ordinary stereo recordings (not

M/S), the cable marked in red shouldcarry the right channel signal; it shouldcarry the signal from the "side" (figure-8) capsule in M/S recording.

6. Setting the preamp gain

When recording, the GAIN control<2> should be set as high as possiblefor the sake of a good signal-to-noiseratio. It is set correctly if the red LED ofthe signal level indicator <1> lights uponly rarely and very briefly during theloudest passages to be record ed.Setting the gain any higher will pose adanger of overload distortion.

When using the VMS 5 U for dema-trixing after recording, the GAIN controlshould be set to 4 or 10 dB again byobserving the yellow and red LEDs.

Please note: Phantom power shouldbe turned off when dematrixing afterrecording. Please remove headphonesor turn the headphone volume controlto its lowest setting when turning offphantom powering.

7. Balance setting

To compensate for a possible differ-ence in the sensitivity of the micro-phones, the Balance knob <3> can beused to adjust the relative gain of thetwo channels. When microphones ofequal sensitivity are used, the balance

10. Connecting the outputs

For A/B, X/Y or ORTF recordings thetask of the VMS 5 U is to amplify andfilter the signals presented to its inputs,and to deliver the result to the outputs<17>. For this purpose the "Output"switch (<7> on page 3) must be in its"Preamp" setting.

For M/S recordings there are twopossibilities. The M and S signals canbe sent through the matrix and theresulting L and R signals recorded("Output" switch in the "Matrix" posi-tion), or the M and S signals can berecorded directly, and dematrixed insubsequent playback (switch in the"Preamp" position). Dematrixed L andR signals can be monitored while theM and S signals are being recorded.

If possible, the equipment to whichthe main outputs of the VMS 5 U areconnected should have balanced inputsfor best possible rejection of hum andradio-frequency interference. Not allrecorders offer balanced inputs, butwith short cables (less than a fewmeters) this is generally not so critical.If you need to connect the output ofthe VMS 5 U to an unbalanced input,the best way is to connect pin 2 of theVMS 5 U's output to the "hot" contactof the input, while the shield of thecable to the recorder’s inputs shouldbe connected both to pin 1 and thehousing of the XLR connector at theVMS 5 U’s outputs.

With equipment whose circuit ground

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is not directly connected to its chassisground, the risk of interference can belessened by using shielded, two-con-ductor cable. As before, pin 2 of theVMS 5 U's output should be connectedto the "hot" contact of the input,while the circuit ground will be carriedby pin 3 of the output, and the cableshield will then merely connect the twocomponent housings with one another.

Connecting the VMS 5 U to an unbal-anced input

VMS 5 U

recorder

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2

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11. Connecting headphones

Any stereo headphones with animpedance of 32 to 2,000 Ohms canbe connected to the headphone out-put of the VMS 5 U. Headphones witha miniature plug can be used with acommonly available adapter.

The headphone output is used formonitoring; a switch <9> selects eitherthe unaltered "PREAMP" signals (e.g.for A/B, X/Y or ORTF-style recording)or the "MATRIX" outputs (left and rightsignals derived from an M/S recordingsetup).

Please note: When turning phan-tom power on or off, or when settingthe input selector switch, please turnthe headphone volume control to itsminimum setting.

In the interest of hearing conserva-tion, do not monitor at high soundlevels. Prolonged listening throughheadphones at high levels can damageyour hearing more severely than listen-ing at what may seem like the equiva-lent level on loudspeakers.

12. M/S recording / WIDTH

M/S is used primarily when recordingsound for film or television, but is alsouseful for music recording. Its advan-tage is that the stereo image can beadjusted after the recording has beenmade, in post-production.

The principle of M/S: As with other

stereo recording techniques (A/B, X/Y,ORTF, "Blumlein" etc.) two micro-phones are used, of which one (the"side" or "S" channel) must have afigure-8 directional pattern; the othermicrophone (the "mid" or "M" chan-nel) may have any desired pattern. Thetwo microphones are placed onedirectly above the other, but while theM-channel microphone is aimed at thesound source, the S-channel micro-phone is aimed 90º to the left (seeillustration, top of page 12). Thus thetwo microphones do not directly pickup the left and right channel playbacksignals; instead, these signals arederived by means of a sum-and-differ-ence matrix circuit such as the one inthe VMS 5 U. The left channel play-back signal is formed by adding M+S,while the right channel playback signalis formed by subtracting M-S. Thisworks because the two lobes of a fig-ure-8 microphone’s pattern are inopposite polarity to one another.

The result is as if two "virtual micro-phones" had been aimed symmetrical-ly with respect to the main axis of theactual M-channel microphone. Thedirectional pattern of these "virtualmicrophones" depends on the actualpattern of the M-channel microphoneas well as on the setting of the "WIDTH"control <6>, which determines the rel-ative gain applied to the M and S sig-nals fed into the matrix.

The "WIDTH" control sets the widthof the stereophonic image. The useful

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range of settings will depend on thetype of microphone used for the Mchannel; the broader its directionalpattern, the farther the "WIDTH" con-trol can be turned up. This control alsoaffects the recording angle – the widestarc, as viewed from the microphones'position, which may be picked upwithout creating ambiguity as to thelocation of sound sources. In general,the greater the directionality of the M-channel microphone, the narrower therecording angle will be (see the dia-grams on the opposite page).

The farther the "WIDTH" control isturned up, the greater will be the anglebetween the "virtual microphones." Therecording angle, on the other hand,

will become narrower. Any soundsources located beyond that angle(near the edges) will be picked up outof phase, and will seem to jump overto the channel opposite from wherethey were in reality.

The optimal WIDTH control settingdepends on the directional pattern ofthe microphone being used for the Mchannel, the relative sensitivity of thetwo microphones, and the recordingenvironment. Setting "4" would be asuggested starting point.

In M/S recording, the WIDTH controland the balance setting both controlthe relationship of M to S, thus affect-ing the stereo image width and therecording angle as well. When using

One possible way to set up an M/Smicrophone arrangement:

top: cardioid as M microphonebottom: S microphone (figure-8)

The MK 8 as viewed fromthe front, when the micro-phone is used horizontallyas shown.

red dot

0°

S→channel II

M→channel I

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ϕ = one-half the recording angle,α = one-half the angle between the two “virtual microphones”

“Virtual microphones” in an M/S recording, showing the left channelresult (M+S) when a cardioid is used for the M-channel microphone

Extreme settings of the WIDTH controlcan lead to unexpected and possiblyundesirable results. A sound sourcethat is moving from left to right, forexample, will normally be heard in asteadily decreasing degree in the left-channel output signal. But if thatsound source crosses past the null inthe polar diagram of the left-channel"virtual microphone" (see above), its

presence in the left-channel outputsignal will begin to increase again. Thiswill cause it to be located incorrectlywithin the stereo image. The signalwill also be out of phase, which cancause further problems: in a DolbySurround recording, for example, thissound source could be audible in thesurround-channel loudspeakers.

main stereo axis

Increasing ratio of S signal to M signal

(unusable)

mono

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microphones of equal sensitivity, theBALANCE knob should normally be ator near its center setting. If micro phonesof unequal sensitivity are used, theBALANCE control should be set so asto compensate for as much as possibleof the difference; otherwise theWIDTH control may not offer a usefulrange of settings.

M= MK 2, C

CM 2

M= MK 21, C

CM 21

M= MK41, C

CM 41

M= MK4, C

CM 4

Effect of the WIDTH control on the recording angle, for varioustypes 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 7 8 9 10

0 1 2 3 4 5 6 7 8 9 10

+10 dB

-10 dB

-20 dB

0 dB

180°

60°

0°

120°

The BALANCE control is calibrated tothe sensitivity of Schoeps microphones,with a cardioid as the “M” channelmicrophone of reference. When using aSchoeps super-cardioid for the “M”channel, the default setting of theBALANCE control would be 2 dB tothe left of the normal center setting.

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13. M/S dematrixing in post-production

If the M and S channels of an M/Srecording are recorded directly, theycan be dematrixed afterward by theVMS 5 U to produce left- and right-channel signals. The recorded signalscan simply be fed into the inputs (withphantom power turned off!) and theOUTPUT switch set to the "MATRIX"position. The stereo image width canthen be adjusted with the WIDTH con-trol. Typically the GAIN knob <2>would be set to the 4 dB or 10 dBposition.

This capability is especially valuablebecause monitoring a live recordingover headphones may not allow theengineer to find an optimal setting forthe stereo image width as it would bereproduced through loudspeakers.

In addition to experimenting withvarious width settings, it can some-times be very useful to equalize the Mand S channels separately. For exam-ple, boosting the frequencies below100 Hz in the M channel prior todematrixing can increase the sense ofspaciousness in a recording withoutupsetting the accuracy of its overallstereo imaging (not recommended forLP recordings, or where there is exces -sive low-frequency noise or “roomrumble”).

14. M/S side inversion

switch

Whenever a pair of microphones issuspended overhead, the sense of leftand right can become reversed. In M/Srecording with the “M/S side inversionswitch” <5> the output channelassignments can be corrected if thisshould occur.

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15. Technical Specifications

InputsSwitchable 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 (5Vrms)

at 20 dB gain setting: -2.2 dBV (780 mVrms)

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.

OutputsThe 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 Vrms)

Recommended load impedance: 2 kOhm or

greater

Headphone outputSwitchable; 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

FiltersAn 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.

PoweringAn 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)

ca. 7 hours (1600 mAh NiMH)

ca. 12 hours (3400 mAh gelled lead acid bat-

tery (external))

A voltage indicator displays the battery voltage

within the unit.

A warning LED will begin to blink if the voltage

falls beneath a critical value (time remaining

at that point with most higher-capacity

rechargeable batteries: at least 10 minutes).

The unit will shut itself off automatically to help

prevent damage from draining the batteries

completely.

External poweringAn appropriate AC power adapter is available

(model VMS 5 DC). Other adapters offering a

regulated output voltage of 6 Volts DC (at

500 mA) to 15 Volts DC (at 250 mA) can also

be used. Under no circumstances should an

open-circuit voltage of 16 V be exceeded;

otherwise a fuse inside the VMS 5 U will

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 disconnected (indicated

by yellow LED “EXT.”). This protects the bat-

teries from being discharged unintentionally.

The battery voltage indicator displays the level of

any external powering.

External powering with outboard rechargeable

battery: nominal 6 – 12 V; we recommend

gelled lead-acid batteries (6 V, 3400 mAh

type = 12 hours of operation).

Parallel operation of a VMS 5 U along with one

or more other pieces of equipment from a

single power supply is generally possible,

because of the internal voltage regulation.

Robust, black aluminum case.

Overall measurements: (W × H × D):

162 mm × 60 mm × 172 mm

(approximately 6-2/3” × 2-1/3” × 6-3/4”)

Weight (with batteries): 1.1 kg (approximately 2

lb. 7 oz.)

These specifications are subject to revision and

correction with out notice.

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16. Block diagram

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Frequency response curves: above: without low-cut filter; below: with low-cut filter

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17. Important information

The VMS 5 U was designed for profes-sional applications in indoor and out-door recording, but should be usedonly in a dry place (e.g. not in the rain,since that could cause a hazardouscondition for the user as a result of ACpowering). Apart from that potentialhazard there is also the risk of waterdamage to the unit itself.

Do not operate the unit in strong, directsunlight because of the risk of over-heating internal batteries. The allowabletemperature range is -20° C to + 50° C.

The headphone volume levels whichcan be achieved with this unit can, withprolonged use, cause lasting damageto one’s hearing. Please monitor only atthe minimum necessary levels.

Cables: Use only shielded cable with atleast 90% shield coverage. All SCHOEPScables fullfill this requirement.

Declaration of conformity

For the VMS 5 U we herewith declarethat it complies with the directive89/336/EWG on EMC (electromagneticcompatibility) of the EC council.

This product is not subject to furtherdirectives.

For the judgement of this product inrespect of EMC the following stan-dards are applicable:EN 55103–1, EN 55103–2

The manufacturer accepts full respon-sibility for this declaration.

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18. Warranty

We guarantee our products for aperiod of twenty-four months, exceptfor cables, batteries and cells (includ-ing rechargeable batteries and cells)and any other products of other man-ufacturers for which SCHOEPS is onlythe reseller; for these products theperiod of guarantee is six months. Theguarantee period begins on the dateof purchase. Please provide your bill ofsale in all cases as proof of guarantee;without it, repairs will be undertakenonly at the owner’s expense.

We reserve the right to satisfy allwarranty requirements regarding defectsof workmanship or materials by meansof repair or partial or complete replace-ment of the unit, at our sole discretion.

Excluded from this guarantee aredefects due to misuse (e.g. incorrectoperation; mechanical damage), abuseor “acts of God.” This guarantee isnullified in the event of tampering byunauthorized persons or agencies.

To secure your rights under this guar-antee, send the unit with all includedaccessories and proof of purchase, atyour expense, either to SCHOEPS (ifyou are a customer in Germany), or toour representative (if you are a customeroutside of Germany).

In exceptional cases you can, byprior arrangement with SCHOEPS,send a unit directly to us from a for-eign country. But since any returnshipment to a foreign customer mustbe prepaid, this would be slower espe-cially when the conditions for serviceunder guarantee are not met; all pay-ment must then be carried out beforethe repaired item could be returned tothe customer.

This guarantee does not affect anycontractual agreements which mayexist between the buyer and seller ofthe equipment.

This guarantee is world-wide.

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Subject to change without notice010102