Creek Audio OBH 18 User manual

SPECIFICATION Creek OBH 18
GAIN 37dB Phono Pre-Amplifier
FREQUENCY RESPONSE 20 Hz to 20 kHz +/- 0.25 dB
SIGNAL TO NOISE RATIO -86 dB
TOTAL HARMONIC DISTORTION < 0.03%
RIAA DEVIATION +/- 0.1%
OUTPUT 250 mV
OUTPUT IMPEDANCE < 100 W
INPUT SENSITIVITY/IMPEDANCE 3.5 mV / 47 k
OVERLOAD MARGIN 22 dB Operating
MATES WELL WITH MM CARTRIDGES 2.5 mV - 5.5 mV output Instructions
DIMENSIONS 150 x 100 x 66 mm
POWER SUPPLY VOLTAGE 24V DC 30 mA Thank you for purchasing the OBH 18 phono pre-amplifier. You are
now in possession of a state-of-the-art product. The functions and
operation of the OBH 18 are extremely simple. The following notes
WARRANTY are provided to explain all aspects of its design and use.
If within two years of the purchase date your OBH product proves to
be defective for any reason other than accident, misuse, neglect, The function of the OBH 18 is to boost the level and correct the
unauthorised modification or fair wear and tear, Creek Audio Ltd frequency response of a low level signal coming from a phono pick-
will, at its discretion, replace the faulty parts without charge for up on a conventional turntable.
labour or return carriage within the U.K.This warranty is valid only
within the U.K. and given in addition to statutory rights. Service The signal required by most modern amplifiers is described as
enquiries outside the U.K. should be addressed first to the being 'LINE' level, which is, in technical terms, between 200 and
supplying dealer and or Creek distributor/importer. Warranties 500 milli Volts with a flat frequency response.
granted in these countries are entirely at the discretion of the
distributor. Unless your amplifier has a specific 'Phono' or Disc input, the level
will be too low and the frequency response will be wrong. The
Creek Audio Limited OBH 18 is designed to boost the signal and introduce an R.I.A.A.
12 Avebury Ct, Mark Road, Hemel Hempstead HP2 7TA England frequency response characteristic.
Telephone: [phone] Fax: [phone]
E-mail: [email protected] Web: www.creekaudio.com
W/220 pF

INPUT AND OUTPUT CONNECTION WIRING THE OBH 18
The output from the turntable is normally terminated on two
'Phono' plugs or RCA jacks. The level is dependent on the type of
cartridge used, and in the case of moving magnet will normally be
around 2 - 5 milli Volts and for moving coil - 200 - 500 micro Volts.
Most MM cartridges will be properly matched by using the OBH 18.
By plugging the signal leads from your turntable into the OBH 18
input, the signal will be boosted to 'LINE' level at its output. To
prevent hum pick-up, it may be necessary to join the turntable's
earth lead to the OBH 18 ground terminal.
The output from the OBH 18 can be connected to most integrated
amplifier’s and pre-amplifier's line inputs via a regular Phono to
Phono (RCA to RCA) stereo interconnect lead.
The output impedance of the OBH 18 is <100 W, therefore it can be used
to drive long interconnects without loss, provided they are high
capacitance types.
Connect the OBH 18 to the input of your amplifier with a stereo
POWER SUPPLY REQUIREMENTS
RCA inter-connect cable. If using a Creek integrated amplifier
In common with all electrical appliances, the OBH 18 requires a
connect to the first input.
power supply.
The connection for the phono output from the turntable plus
The requirement for the OBH 18 is for 24 Volts DC at 30 milli-Amps
ground is clearly marked on the rear panel.
current, minimum. A custom Creek power supply (Creek-Uni) has
been provided and this must be connected via the DC inlet on the
The power supply is connected to the 2.1mm positive pin power
rear panel of the OBH 18.
jack and then to the wall socket. The OBH 15 should be placed
away from power supply hum fields for the lowest noise operation.
The power supply which has been provided is a
NOTE
Due to the inherent muting circuitry in the OBH 18, the signal will
take a few seconds to be heard after the power is switched on.
It is necessary for the OBH 15 to be ‘burned in’ for at least 24 hours
before its full sound quality potential can be realised.
The on/off switch is located on the rear panel. As the OBH 18 draws
very little power it may be left switched on permanently.
switchable supply
with a universal input range of 100 – 240 Volts. The Creek-Uni
power supply is supplied with a pack of universal plug fittings to
adapt for Europe, U.K. and the Far-east, USA and Australia.
Choose the correct fitting for your country of use and simply snap
in place.