The OBH-21mk2 is essentially a very high quality miniature integrated amplifier, designed specifically to drive two pairs of low impedance headphones simultaneously from a line level source, such as a CD player, DAC, or amplifier without headphone output. It can even drive demanding 8 Ohm headphone if called upon to do so. Unusually, it is also designed to act as a single input high quality pre-amplifier, if required. Its output level is controlled by an audiophile quality ALPS 27mm Blue Velvet volume control on the front panel and by user adjustable gain setting switches on the bottom of the case.
The OBH-21mk2 has three pairs of stereo RCA sockets on the rear panel for Line level input, looped Line level output, and a variable pre-amp output, whose gain can be set, independently from the headphone gain for the greatest flexibility.
OBH Uni Power Supply Adaptor:
The OBH-Uni is a multi-region, 24V, 0.5A power supply adaptor. Creek originally developed this power adaptor to simplify the requirements for selling OBH products in all countries. However, extensive listening tests and comparisons proved that this high efficiency regulated power adaptor can also extract the best performance from all of Creeks OBH products. This includes the latest OBH-15mk2 Phono Pre-amp, which has high-gain and is therefore more demanding of its power supplys purity.
It is supplied with three different snap-on power-plugs suitable for Europe, UK and USA. The snap-on head on the latest version of OBH-Uni uses a 2 pin, figure 8 connector, so its possible to use a 2 pin figure 8 extension power cord, with alternative mains plugs on the end. It provides a stable output from any input mains voltage range from 100 240V.
Strict international regulations make it unacceptable to use conventional linear power adapters because, if they are left permanently switched-on, their standby power will definitely exceed the 0.5W limit. The latest OBH-Uni draws less than 0.5W when idle, or plugged-in but not used. It is also silent in operation, from zero to maximum current consumption.
Output Power: > 100mW / 8 Ohms, > 160mW / 16 Ohms, > 200mW / 33 Ohms, > 210mW / 68 Ohms
Headphone Impedance: 8 to 1k Ohm
Output Impedance: 1 Ohms
Input Impedance: > 7 k Ohms
Frequency Response: 10 Hz to 50 kHz
THD Headphone Out: < 0.002% from 20 Hz to 20 kHz at 0.5V into 68 Ohms
SNR Headphone Out: 116dBA ref 1V, 107dBA at 12.5dB gain
THD Pre-Amp Out: < 0.0006% from 20 Hz to 20 kHz
Crosstalk Line Out: > -80dB, 10Hz 20 kHz Line out
Crosstalk Headphone Out: > -60dB headphone output 33 Ohm
Gain Settings: 0dB, 6dB, 10dB and 12.5dB
Power Consumption: < 6 Watts at max power, < 0.5 Watts standby
Power Supply: 24V DC 12 Watts max
Size: 7" x 3.75" x 2.25"
Weight: 1.38 lbs