Фонокорректоры — Creek Audio OBH-8mk2

The OBH-8mk2 is a standalone moving magnet phono preamplifier from Creek Audio of London and the entry point to the company's phono range. It replaces the original OBH-8 and was created because many current amplifiers no longer offer a built-in phono input. Its task is to raise the small cartridge signal and apply RIAA equalisation so that a turntable can feed any line-level input. The UK list price is GBP 129, and black is the sole colour option for the case.

Key specs that matter

The amplification is a fixed 40 dB, a factor of 100. The input is matched to 47 kOhm resistance, suited to standard moving magnet cartridges. Total harmonic distortion plus noise stays below 0.003 percent at 2 V RMS output, frequency response runs from 10 Hz to 100 kHz within 0.5 dB, and channel separation exceeds 70 dB. Maximum output reaches about 6 V RMS, and the overload margin is quoted at around 21 dB. Output impedance is below 100 ohm. The unit is about 100 mm wide and weighs roughly 0.4 kg including its power adapter, drawing about 3 W from mains between 100 V and 250 V at 50 or 60 Hz.

Engineering and use context

Unlike its predecessor, the mk2 uses a completely new circuit built around an integrated circuit MM stage. Creek fitted constant current sources to the output of the gain stage, which push it into Class A operation to lower distortion. Together with the low output impedance, this lets the OBH-8mk2 drive long cable runs to the amplifier. The supply from the external adapter is split into positive and negative rails by a custom discrete Creek circuit, and two capacitance multipliers then filter each rail before it reaches the preamplifier stages, cutting ripple to a very low level. For the mk2, Creek also developed a new low-profile metal case that brings the cost down while keeping build quality, and it sits as a small companion to the full-width Creek components. The maximum output leaves a wide margin above the level used for the distortion figure, and Creek describes the circuit as effectively impossible to overload by conventional means.

Pairing

The OBH-8mk2 goes between an MM-equipped turntable and a line input on an amplifier, receiver or active speaker system that lacks its own phono stage. Because both gain and input loading are fixed, there are no switches to set for the cartridge. There is a single input, so only one turntable can be connected at a time.

Alternatives

The Creek Sequel-mk4 is the other phono preamplifier in the current range, sold as a plug-in phono module instead of a standalone box.