Creek Audio OBH22 User manual

Thank you for purchasing the OBH-22 Infra-red remote control passive Pre-Amp.
You are now in possession of a State of the Art product. The functions and operation
of the OBH-22 are extremely simple. However, the following notes are provided to
explain all aspects of its design and use.
OVERVIEW
The function of the OBH-22 is to provide input selection
and volume adjustment to your Hi-Fi system from your
armchair, via infra-red remote control.
The unit consists of a high quality motorised volume
potentiometer, and two stereo relays which select the
desired input and tape output, together with a muting
relay that can short the signals to ground. A built-in
micro-controller decodes the infra-red signals transmitted
by the handset and translates them into commands
which activate the motorised potentiometer and the
muting and input selection relays. After each operation,
the micro-controller turns itself off to avoid any possibility
of interfering with the main music signal. LED’s are used
to indicate the status and mode of operation.
The OBH-22 is purely passive and does not introduce
any gain or distortion into the signal path. It is therefore
suitable to be used as a control Pre-Amp, provided the
sensitivity of the power amp that is being used is high
enough to be driven directly from the source. i.e. CD or
Tuner etc.
CREEK OBH-22 SPECIFICATION
INPUT IMPEDANCE < 20 kΩΩ
OUTPUT IMPEDANCE 0 - 20 kΩΩ
SEPARATION > 80 dB's @ 1kHz
ATTENUATION 0 - 90 dB's
INPUTS 3 Stereo pairs, inc Tape
OUPUTS 2 Stereo pairs, 1 fixed, 1 variable
RELAY MUTING FACTOR > 90dB's
POWER REQUIREMENTS 24v @ 60 mA
POWER CONSUMPTION 2W max
DC CONNECTOR TYPE 2.1 mm female DC jack
INPUT & MUTE INDICATION 2 LED
SIZE 150 x 100 x 66 mm
6” x 4” x 2 1/2”
WEIGHT 610 g, 1.3 lb
Creek Audio Ltd reserves the right to change or modify
the specification of its products without prior warning.
Creek Audio Ltd
12 Avebury Court, Mark Road, Hemel Hempstead HP2 7TA, England
Telephone: [phone] Fax: [phone]
E-mail: [email protected] Web: www.creekaudio.com
Designed and made in the UK.
Creek OBH-22
Operating
Instructions
ARC53 Remote
Handset

The volume control can be operated manually at any time, whether the OBH-22
is powered or not, but without power only Line 1 can be utilised.
MAINS CONNECTION
When unpacking the module please
keep the packing material in a safe
place for possible future use. In the
pack there is a separate mains
adaptor, prepared for the mains
voltage supply in the country of use.
The plug at the end of the fixed
cable should be firmly inserted into
the connector on the OBH-22 rear
panel marked “DC inlet".
Remember, do not overload the
mains wall socket with too many
plugs or adaptors. If in doubt, please contact your supplying dealer or a qualified
electrician. The OBH-22 draws less than 2 Watts of power from the mains under
all conditions so it can safely be left switched on without significantly increasing
your electricity bill.
INPUT AND OUTPUT CONNECTIONS
Line 1 and 2 are identical. The output from a CD, Tuner, AV or from an OBH-15
or OBH-18 phono pre-amp can be connected to either of them. For tape
machines, use the Tape input and output - the tape monitor function will allow
recordings to be made and played back. The output from the OBH-22 should be
connected to a power amplifier with suitable sensitivity (gain). Remember, the
OBH-22 will not increase the signal from input to output.
VOLUME LEVEL
The volume control is used to alter the relative level of the sound output from the
amplifier. It is important to realise that the volume control only acts to reduce, or
attenuate, the incoming signal to the power amplifier stage. The maximum power
of an amplifier is available only if the level of signal available from line level
equipment is sufficient to drive it to clipping, which will be different from one
amplifier to another. The volume control is therefore also used to balance the
level from one piece of equipment to another.
If it is found necessary to have the volume control set to a position which is
considered to be high before the desired level of volume is obtained, it does not
necessarily mean that the amplifier is having to work too hard or "flat-out".
Consult your dealer if you need more advice. Always have the volume control set
at minimum (counter-clockwise) when switching your amplifier on and off, to
avoid thumps or sudden loud noises.
POSITIONING OF THE OBH-22
The OBH-22 needs to be powered from its adaptor to operate the volume, input
and mute functions via the remote control. It will work best if placed on a suitable
hard surface or Hi-Fi equipment cabinet. Should it be necessary to place the
OBH-22 on the top of other audio or video equipment, avoid obstructing any
ventilation slots that could cause overheating, or internal mains transformers
which might induce hum pick-up. Very heavy signal interconnects may cause the
OBH-22 to tip backwards. There are two slots on the bottom that could be used
to lock it in position. Do not obstruct the IR sensor on the front panel.
OPERATING THE OBH-22 BY REMOTE CONTROL
The OBH-22 has three line inputs including tape, which can be selected either
from the front panel buttons or remote handset. The appropriate LED above each
button will indicate which one is selected. Volume level can be adjusted
manually from the control knob on the front panel or by using the up and down
buttons on the remote handset. Remote volume changes will cause the input
indicator LED to flash.
Pressing the Mute button on the front panel or remote handset will short the
signal to ground and the LED indicator will light above the button. To un-mute,
press the Mute button again or the volume up button (volume down will not
un-mute the signal). To un-mute the OBH-22 without the handset, remove the
power supply for 10 secs. To select the tape player or to monitor a tape
recording press button ‘Tape 1’. The LED indicator will light. Press button
‘Tape 1’ again to switch this off. All other buttons on the handset are reserved for
other Creek remote controlled products.
CAUTION
Your OBH-22 amplifier is designed to give you years of reliable use. However, it
is necessary to take care of your possession, so never overheat and only use the
recommended Creek OBH 1 power supply.
The OBH-22 is designed to comply with European EMC requirements. However,
it should be noted that it is not possible to guarantee faultless operation of the
equipment if it is used close to the source of high powered radio transmissions,
such as can be found in mobile telephones or CB radio etc. Care should also be
taken to place it away from the source of mains interference caused by mains
transformers in other equipment. Electrical switching noises from domestic or
industrial heating systems, conducted periodically down the mains supply, can
sometimes be amplified and present themselves as a click or a thump through a
Hi-Fi system.
If you suspect that a fault has developed, do not remove the cover plate. There
are no user serviceable parts inside. If you are unfortunate enough to need
service work carried out on the OBH-22, it should be returned to your dealer for
his expert help, in the original packing material if possible.