Фонокорректоры — Boulder 2108

The 2108 is the reference phono preamplifier of Boulder Amplifiers, the Colorado manufacturer with its own production facility in Louisville. Launched in 2019 as part of the 2100 Series, it is the second generation of Boulder's top phono stage, following the 2008. It separates the audio circuits and the power supply into two chassis and handles three turntables through fully balanced inputs.

Key specs that matter

There are three pairs of balanced inputs, convertible to unbalanced, and two pairs of balanced outputs with 100 ohm output impedance. Maximum input impedance is 1000 ohms for MC and 47 kohm for MM. RIAA gain is 70 or 60 dB for MC and 50 or 40 dB for MM. RIAA accuracy is within 0.10 dB from 20 Hz to 20 kHz, THD is 0.005% at 1 kHz, crosstalk is -100 dB or better and maximum output is 28 Vrms. Equalisation curves are RIAA, FFRR (London/Decca), EMI and Columbia. The audio chassis weighs 16.8 kg and the power supply 21.8 kg.

Engineering and use context

The gain stage is Boulder's 995S, a modular discrete circuit exclusive to the 2108, hand-built and calibrated inside a potted, precision-machined housing. Compared with the 2008, the 2108 uses improved ground paths and planes, a revised circuit topology and more surface-mount circuitry made on Boulder's own SMD lines, which reduces parasitic capacitance and lead inductance. The lower noise floor allowed Boulder to add gain for low-output MC cartridges without raising noise. Each input takes a Personality Card that sets MM or MC mode, resistive and capacitive loading and high or low gain, so three different cartridges can be matched individually. The additional EQ curves allow correct playback of records cut before the RIAA standard became universal in the mid-1950s. A three-setting low-cut filter removes rumble and warp-induced low frequencies, and switchable pass-through connections accept an external demagnetiser for MC cartridges. The power supply and standby circuits sit in their own chassis, keeping hum away from the high-gain audio stages. The chassis is machined aluminium, non-resonant by design, so it does not pass mechanical vibration into the gain modules. Power consumption is 75 W at most.

Pairing

The balanced outputs and high maximum level suit Boulder's 2110 preamplifier or any balanced line preamplifier. The three Personality Card inputs support a multi-arm turntable or a mix of MM, MC and mono cartridges.

Alternatives

Boulder's 1108 is the single-chassis phono preamplifier of the 1100 Series with balanced circuitry.