Thorens - MC 1600 MM/MC Phono Preamplifier

Thorens’ flagship phono stage: balanced XLR in and out, dual mono, gain from 32 to 68dB in ten steps, impedance from 20 to 1,280 ohms in 20-ohm steps, RIAA within a tenth of a decibel. Made in Germany.

This is the most adjustable phono stage in the shop and it is not close. Gain runs in ten 4dB steps from 32dB to 68dB — enough range to run a hot moving magnet at the bottom and a 0.2mV moving coil at the top, with fine adjustment at every point in between. Input impedance runs from 20Ω to 1,280Ω in twenty-ohm steps, plus a 47kΩ position for moving magnet. Capacitance runs from 50pF to 600pF in fifty-picofarad steps.

That is sixty-four impedance settings where most phono stages give you four. Loading a moving coil is the single largest change you can make to how a cartridge sounds without buying a different one, and twenty-ohm resolution means you can actually find the right answer rather than picking the nearest of four wrong ones. Everything is set by DIP switches on the underside, independently for each channel.

The construction is dual mono with two-stage amplification and both passive and active RIAA equalisation, each channel with its own fully symmetrical amplifier section built from precision resistors, film capacitors and low-noise operational amplifiers. Thorens is straightforward that this is an op-amp design rather than a discrete one, and does not name the parts.

Balanced XLR is present on both input and output, which is why this box pairs so naturally with the TD 1600 and TD 1601 — those turntables have true balanced output, and a cartridge is a floating differential source to begin with. Keeping the whole chain differential rejects common-mode noise that single-ended wiring simply passes on. Two RCA pairs are there too.

The subsonic filter is properly done: a multi-stage design with a 15Hz corner, switchable between off, 6dB per octave and 12dB per octave. Warped records and turntable rumble put energy below the audible band that does nothing but move woofers and eat amplifier headroom, and being able to choose how hard to attack it is better than a single on-off switch.

Published performance: RIAA within 0.1dB from 10Hz to 20kHz, distortion under 0.005%, crosstalk better than 110dB, and a signal-to-noise ratio Thorens states as varying with gain setting from better than 76dBA to better than 100dBA. The power supply is internal and separately shielded, with automatic mains adaptation from 100 to 280 volts.

One oddity in Thorens’ own paperwork: the product page gives the height as 20cm and the manual gives it as 9cm. A 20cm-tall box only 30cm wide would be a strange shape for a component, so the manual’s figure looks right, but both are Thorens’ and we are printing both.

Features

• Gain adjustable from 32dB to 68dB in ten 4dB steps
• Input impedance from 20Ω to 1,280Ω in 20Ω steps, plus 47kΩ for moving magnet
• Input capacitance from 50pF to 600pF in 50pF steps
• DIP switches on the underside, set independently for each channel
• Balanced XLR on both input and output, plus RCA
• Dual mono construction with passive and active RIAA equalisation
• Multi-stage subsonic filter at 15Hz, switchable off / 6dB / 12dB per octave
• RIAA accuracy within 0.1dB, 10Hz–20kHz
• Crosstalk better than 110dB
• Internal separately shielded power supply with automatic mains adaptation
• Configurable RGB front illumination
• Made in Germany

Specifications

• Type: Moving-magnet and moving-coil phono preamplifier, dual mono, balanced
• Cartridge support: Both moving coil and moving magnet, at low and high output. There is no dedicated MM/MC mode switch — moving-magnet operation is selected by setting the input impedance to the 47kΩ position
• How the settings are made: DIP switches on the underside of the chassis, set independently for each channel
• Gain: 32, 36, 40, 44, 48, 52, 56, 60, 64 and 68dB — ten steps of 4dB
• Input impedance: 20Ω to 1,280Ω in 20Ω steps, plus a 47kΩ position for moving magnet
• Input capacitance: 50 to 600pF in 50pF steps
• Maximum output level: 10V rms. Maximum output current 100mA rms
• Output impedance: 50Ω on RCA; 110Ω on XLR
• RIAA accuracy: Maximum 0.1dB deviation, 10Hz–20kHz
• Signal-to-noise ratio: Better than 100dBA down to better than 76dBA referenced to 2V, depending on the gain setting, with a 100Ω source. Thorens publishes this as one gain-dependent specification rather than separate MM and MC figures
• THD: Less than 0.005%
• Crosstalk: Better than 110dB referenced to 2V, stated as independent of gain setting, with a 100Ω source
• Subsonic filter: Multi-stage, 15Hz corner frequency, switchable between off (DC), 6dB per octave and 12dB per octave
• Alternate EQ curves: None. RIAA only
• Circuit: Dual mono with two-stage amplification and both passive and active RIAA equalisation. Each channel has its own fully symmetrical amplifier section built from precision resistors, film capacitors and low-noise operational amplifiers — an op-amp design rather than discrete. Thorens names no specific parts
• Inputs: 2 x RCA and 2 x XLR
• Outputs: 2 x RCA and 2 x XLR
• Power supply: Internal, in a separately shielded section. 100–280V with automatic mains adaptation. No external upgrade supply is offered
• Dimensions: Thorens contradicts itself. Their product page gives 300 x 200 x 301 mm (W x H x D); their own manual gives 300 x 90 x 301 mm. Width and depth agree; the height differs by more than a factor of two. A 20cm-tall component only 30cm wide would be an unusual shape, so the manual’s 90mm looks the more plausible, but we are not going to overwrite a manufacturer figure
• Weight: 5kg
• Finish: Brushed black aluminium, with configurable RGB front illumination
• Country of manufacture: Made in Germany, stated explicitly on Thorens’ own product page