Creek Audio OBH 21 User manual

SPECIFICATION Creek OBH 21/21SE
STANDARD Headphone Amplifier
OUTPUT POWER > 10 mW into 30Wto 300Wloads
HEADPHONE IMPEDANCE
THD < 0.01% at 1 kHz
SIGNAL TO NOISE RATIO > 70 dB
POWER CONSUMPTION < 4VA
POWER SUPPLY 24V DC 150 mA
DIMENSIONS 180 x 100 x 66mm (7.4 x 4 x 2.6 “)
WEIGHT 570 gms (20 ozs)
SPECIAL EDITION
OUTPUT POWER
HEADPHONE IMPEDANCE
THD
SIGNAL TO NOISE RATIO Operating
POWER CONSUMPTION
POWER SUPPLY Instructions
DIMENSIONS
WEIGHT Thank you for purchasing the OBH 21/21SE headphone amplifier.
You are now in possession of a state-of-the-art product. The
functions and operation of the OBH 21/21SE are extremely simple.
The following notes are provided to explain all aspects of its design
WARRANTY 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 OBH 21 is a miniature audio amplifier, designed specifically to
unauthorised modification or fair wear and tear, Creek Audio Ltd drive two pairs of low to medium impedance (30Wto 300W)
will, at its discretion, replace the faulty parts without charge for headphones from a line level source. The OBH 21SE is a high end
labour or return carriage within the U.K.This warranty is valid only version using more expensive components. It is more efficient to
within the U.K. and given in addition to statutory rights. Service have a small amp do this rather than waste the power of a full size
enquiries outside the U.K. should be addressed first to the one when only driving headphones.
supplying dealer and or Creek distributor/importer. Warranties
granted in these countries are entirely at the discretion of the The OBH 21 and 21SE are compatible with any source at line level.
distributor. For example the average output level of a CD player can be
connected directly to the input of the OBH 21/21SE just as it could
Creek Audio Limited also be used in conjunction with a stand-alone pre-amplifier or
12 Avebury Ct, Mark Road, Hemel Hempstead HP2 7TA England integrated amplifier which doesn’t have a headphone socket.
Telephone: [phone] Fax: [phone]
E-mail: [email protected] Web: www.creekaudio.com
30Wto 300W
> 10 mW into 30Wto 300Wloads
30Wto 300W
< 0.005% at 1 kHz
> 70 dB
< 6VA
24V DC 250 mA
180 x 100 x 66mm (7.4 x 4 x 2.6 “)
570 gms (20 ozs)

INPUT AND OUTPUT CONNECTION INSTALLATION AND OPERATION
The OBH 21/21SE is not designed to be connected to the high Connect the Creek Uni power supply adaptor to the mains socket.
level speaker output of an integrated or power amplifier. Output Find a suitable place for the OBH 21/21SE and plug the DC power
level is controlled by the high quality volume control on the front lead into the rear panel DC jack socket.
panel.
Connect a pair of high quality interconnect cables from the output
of the source to the input sockets on the rear of the OBH 21/21SE.
The OBH 21/21SE has two pairs of stereo phono sockets (RCA
jacks) on the rear panel. The first pair is the input from any line
There are several wiring options.
level source direct from the source or via the tape output of an
amplifier. The second pair of sockets marked ‘output’ are to chain
OPTIONA
link the signal on to the next component in the system. Therefore
Connect directly from the output of a CD player to the input of the
the OBH 21/21SE can be driven from the Tape Output of an
headphone amplifier
amplifier and the second set of sockets can be used to link the
signal to the Tape Recorder input.
OPTION B
Connect the output of the CD player to the input of the headphone
POWER SUPPLY REQUIREMENTS
amplifier (as in Option A) Then connect the output of the
In common with all electrical appliances, the OBH 21/21SE
headphone amplifier to the input of a stereo amplifier.
requires a power supply.
OPTION C
The requirement for the OBH 21/21SE is for 24 Volts DC at
Connect the output of a CD player to the input of a stereo amplifier.
150 mA. A custom Creek power supply (Creek-Uni) has been
Connect the output of the stereo amplifier to the input of the
provided and this must be connected via the DC inlet on the rear
headphone amplifier (as in Option B). Then connect the output of a
panel of the OBH 21/21SE.
tape deck to the input of the stereo amplifier and the output of the
headphone amplifier to the input of the tape deck.
The power supply which has been provided is a
Plug the headphones into the socket on the front panel. If you are
using the OBH 21/21SE with two pairs of headphones, the output
from each socket will be identical. However, if you are using only
one pair of headphones, the impedance on each socket will be
different. This feature is designed to give a better match with your
particular headphones.
NOTE
Due to the circuitry charging up it is normal to hear a small thump through
Try each socket to determine the best results.
the headphones during switch-on.
Push the On/Off button on the rear panel to power up the
It is necessary for the OBH 21/21SE to be ‘burned in’ for at least 24 hours
headphone amplifier. the small green LED on the front panel will
before its full sound quality potential can be realised.The on/off switch is
light when it is ready for use.
located on the rear panel. As the OBH 21/21SE 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.