Cambridge Audio Duo MM/MC phono preamplifier

This new Cambridge Audio Duo MM/MC phono preamplifier is an upgrade of the Cambridge Audio CP2 phono preamp.

CAMBRIDGE AUDIO DUO: FRONT AND BACK PANEL

This amplifier has the same casing as the previous version but the brushed finish is a little different. The front panel has the brand logo engraved in it, a power on/off button equipped with a LED and a cartridge type (MM or MC) selector button.

Unlike its predecessor, it has 6.35mm jack headphone output, and of course, a volume potentiometer.

The back panel includes two sets of RCA MM and MC inputs as well as a ground screw and a set of RCA outputs. There is also a strange balance control! The manufacturer is trying to convince us that this balance control has a purpose... but honestly I am still looking for one… But it is there just in case!  

The external DC power supply of the CP2 has disappeared and instead there is an IEC plug.

CAMBRIDGE AUDIO DUO: POWER SUPPLY

However, when opening the device, we can clearly notice that unlike some manufacturers, Cambridge Audio has not opted for a traditional (but efficient!) power supply with transformer, diode bridge, and capacitance. The manufacturer has instead integrated a switched-mode power supply! Strange… and debatable.

CAMBRIDGE AUDIO DUO: ELECTRONICS

Regarding the audio scheme, Cambridge Audio has made several improvements. The audio signal has been shortened (use of CMS) and the quality of the components improved. The RIAA correction is passive and the gain is given by a class A amplification stage. The energy consumption has been reduced and, ecologically, the Cambridge Audio Duo automatically powers down if no input signal is present for more than 20 minutes.

This Cambridge Audio Duo is only compatible with MM cartridges or high output MC cartridges that have an output level superior to 3mV. It is also compatible with low output MC cartridges that have an output level superior to 0.5mV.

The data announced by Cambridge Audio (in MC) are flattering: the signal-to-noise ratio is -75 dB, the bandwidth is 30 Hz - 50 kHz, and the total harmonic distortion is inferior to 0.0020%!

Regarding the headphone amplifier, the manufacturer is very vague, silent even. We have no information on the design used and technical characteristics.

CAMBRIDGE AUDIO DUO: TESTING AND LISTENING

The listening experience is faithful to the sound signature of the Anglo-Saxon manufacturer.

The sound restitution is very analogue and does not show any harshness.  

The dynamics are present, even though, with some Hi-Fi headphones, there is a reduction in dynamics. Whatever the style of music you listen to, there is no aggressiveness. On symphonic music, we can appreciate the timbres. Moreover we have enough precision to distinguish the different instruments.  

The midrange is particularly present.

This Cambridge Audio Duo phono preamplifier will not please everyone due to its relatively typical restitution. Its main interest is that in this price range it comes with a headphone amplifier. As a phono preamp, let’s admit it, it has some serious competitors. Bus as a headphone/phono preamp, it is the only one in this price range, and is therefore a must have!