Battery-operated microphone preamplifiers sometimes have high noise figures because current consumption is kept limited in the interests of longer battery life. But the VMS 5 U places hardly any such limitation on the performance of the microphones. In addition, its frequency response leaves nothing to be desired.

One of the characteristics of high-quality equipment is durability. It may be several years before you find out whether the potentiometers and switches on a unit will become noisy when used. In the design of this product, SCHOEPS placed the primary emphasis on reliability and durability, choosing all its components (such as switches and sockets with gold-plated contacts) accordingly.

The unit shuts itself off if the battery voltage falls beneath a certain threshold value, in order to prevent completely draining the batteries and possibly damaging circuit components.

A further quality feature is the all-metal housing, which is unbreakable and protects against radiated electromagnetic interference.

For increased ease of use, the lettering on the back panel is printed upside down relative to the front panel, so that it is unnecessary to turn the unit around in order to read the labeling.
The VMS 5 U with its universal power supply capability and compact dimensions is equally well suited for portable or fixed operation.

A set of batteries is included with the unit. Available separately:
AC power adapter VMS DC, a high-quality switching power supply for 90 - 264 Volt AC.

with switchable phantom powering and M/S matrix

frequency response: 20 Hz - 80 kHz (-3 dB)

two low-cut filters: 20 Hz (permanent) and 150 Hz (switchable)

inputs: XLR-3F (balanced) and special socket for Active Y-Cable of the Colette modular system

outputs: XLR-3M (balanced); easy connection to unbalanced inputs without loss of signal level

headphone monitor output

gold-plated sockets and switch contacts for long service life

glitch-free, automatic switchover to internal batteries in the event of AC power loss

runs on six internal batteries (included) or external DC supply (accessory)

automatic shutoff if voltage gets too low

gold-plated sockets and switch contacts for long service life

black all-metal housing (aluminum)

Frequency response :
20 Hz - 80 kHz (-3 dB)

Input impedance :
20 k

Input :
switchable between two XLR-3F sockets and a special input for the SCHOEPS KCY Active Cable

Input :
recommended minimum sensitivity of microphones at XLR inputs: 8 mV/Pa

Maximum input level for 0.5% THD :
at 4 dB gain setting: 14 dBV (5 Vrms) at 20 dB gain setting: -2.2 dBV (780 mVrms)

Preamplifier gain :
can be set to 4, 10, 20, 30 or 40 dB

Maximum sound pressure level at 0.5% THD : with CMC 6 and MK 4 (cardioid)
at a gain of 4 dB: 132 dB
at 10 dB: 132 dB
at 20 dB: 130 dB
at 30 dB: 120 dB
at 40 dB: 109 dB

Equivalent noise level :
at a gain of 4 dB: 16.5 dB-A
at 10 dB: 16 dB-A
at 20 dB: 15.5 dB-A
at 30 dB: 15.5 dB-A
at 40 dB: 15.5 dB-A

Equivalent noise level (CCIR) :
at a gain of 4 dB: 27.5 dB-CCIR
at 10 dB: 26.5 dB-CCIR
at 20 dB: 26 dB-CCIR
at 30 dB: 26 dB-CCIR
at 40 dB: 25.5dB-CCIR

Level indicators :
-20 dB, -3 dB

Additional comments :
The BALANCE potentiometer permits compensation for differences in microphone sensitivity up to 20 dB.

Additional comments :
The polarity inversion switch permits rapid change of input channel assignments in M/S recording, as when changing between an upright stereo microphone and one that is hanging downwards.

Output :
The outputs are impedance-balanced and transformerless, and are switchable between the amplified microphone signals and the decoded M/S stereo signals.

Output impedance :
100

Maximum output level for 0.5% THD :
18 dBV (8 Veff)

Minimum recommended load impedance :
2k

Headphone output :
Switchable; either the amplified microphone signals (=left / right for A/B recordings, or mid / side for M/S) or the decoded M/S stereo signals can be monitored.

Output impedance :
32 - 2,000

Output socket :
1/4'' stereo phone jack

Filter(s) :
An infrasonic filter (20 Hz, 18 dB/oct.) is permanently 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 generates and stabilizes the supply voltages permits a wide range of input voltages (5.5 V to 15.5 V).

Battery powering :
Operation with internal batteries (possibly 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 reversing 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 battery (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 1300 mAh rechargeable batteries: at least 10 minutes).

The unit will shut itself off automatically to help prevent damage from draining the batteries completely. The unit resumes operation only after the on / off switch is used.
External powering : An appropriate AC power adapter is available (model VMS DC). Other adapters or external batteries can also be used. They should have at least 6V, we recommend 12V. An open-circuit voltage of 16 V must not be exceeded.

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, the internal batteries are automatically disconnected (indicated by yellow LED "EXT."). This protects the batteries from being charged or discharged unintentionally.

The battery voltage indicator displays the level of an external powering.

Parallel operation of a VMS 5 U along with other equipment from a single power supply is possible.

Dimensions :
Overall measurements: (W x H x D): approximately 6-2/3'' x 2-1/3'' x 6-3/4'' which corresponds to 162 x 60 x 172 mm

Weight :
with batteries: approximately 2 lb. 7 oz. which corresponds to 1.1 kg