Headphone amplifier and phono preamplifier for moving magnet and moving coil cartridges
Our take on the Cambridge Duo by Crutchfield's Eric Angevine
Attention to detail — like the helpful upside-down labeling of each input — is the hallmark of the Cambridge Duo phono preamp.
Attention to detail
If you ask me what makes the Cambridge Duo stand out, it's attention to detail. Inside the beautiful silver chassis are circuit boards with surface-mounted components, and a state-of-the-art switch mode power supply. You can't see any of these excellent design choices, but more importantly, you can't hear them. The Duo amplifies the tiny signal from moving magnet and moving coil cartridges without adding distortion or noise, so you hear only the beautiful music your records contain.
Another small, thoughtful detail: the inputs and outputs on the back of the preamp are labeled so they can be read right-side-up or upside-down. Anyone who's ever had to make connections to a component that's already in place will appreciate that little nuance. There's also a balance knob on the back of the unit so you can fine-tune left/right channel output.
Maybe you're a night owl like me, and you want to dig into your record collection even while others are sleeping. The Cambridge Duo has a built-in headphone amplifier with a full-size 1/4" jack so you crank up your faves without waking up the whole house.
Which headphones should I use with my turntable?
“I usually steer vinyl fans towards headphones with a warm, natural soundstage. Grado headphones are a good place to start — take a hard look at their Reference Series RS2e headphones. Hand-crafted mahogany earcups give you smooth, relaxed highs that pair nicely with vinyl.
Other options include the more budget-friendly Audio Technica ATH-M50x headphones or the top-flight Sennheiser HD 800 S headphones. Both offer the well-balanced, revealing sound you want when you're playing records.”
— Jeff Miller, Crutchfield headphone guy
- compatible with moving magnet and moving coil phono cartridges
- rear balance control knob for fine correction of left- and right-channel cartridge output
- acoustically damped full-metal chassis with thick aluminum front panel
- efficient switch mode power supply reduces audible hum
- circuit board layout uses surface-mount components to reduce noise
- built-in headphone amplifier with full-size 1/4" jack
- gain: 39dB(MM), 60dB(MC)
- signal-to-noise ratio: greater than 90dB(MM), greater than 70dB(MC)
- THD: less than 0.0025%(MM), less than 0.2%(MC) (20-20,000Hz)
Dimensions and Warranty:
- 8-1/2"W x 1-15/16"H x 6-1/4"D
- weight: 2.1 lbs.
- warranty: 1 year
- Our 60-day money-back guarantee
What's in the Box:
- MM/MC phono preamplifier
- 58" AC power cord
- Instruction Booklet
- Important Safety Instructions
Cambridge Duo Reviews
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Phono (MM) Preamplifier: Enjoy every last detail from your vinyl collection with Cambridge Audio's high-quality moving magnet phono stage, the Duo phono preamplifier. Cambridge Audio designed the Duo around exceptional components that deliver the warm and detailed sound that's synonymous with vinyl, all without distorting the signal from your moving magnet or moving coil cartridge.
Note: Due to the low-level signals created by a turntable, not all integrated amplifiers and receivers will let you connect directly to a record player. A phono preamplifier, like the Cambridge Audio Duo, boosts this signal to something an integrated amplifier or receiver can work with.
Carefully Selected Components: To preserve the unique warmth of the vinyl sound, the Duo phono preamplifier has been carefully designed with a state-of-the-art switch mode power supply and a new surface mounted circuit board layout to reduce unwanted noise. The switch mode power supply improves performance by switching outside of audible frequency to drastically reduce hum, while the new circuit board layout uses surface-mount components to reduce noise.
Moving Magnet (MM) & Moving Coil (MC) Compatible: The Cambridge Audio Duo phono pre-amplifier features a moving magnet (MM) input stage and moving coil (MC) input stage. There is a cartridge type selector switch on the front-panel of the phono preamplifier.
- MM Input: If your turntable uses a moving magnet cartridge, connect it to the Duo's rear-panel stereo RCA outputs (labeled "MM L/R" (3-5mV, with 47k ohm, 100pF loading).
- MC Input: If your turntable uses a moving coil cartridge, connect it to the Duo's rear-panel stereo RCA outputs (labeled "MC L/R" (0.3-1mV, with 100 ohm, 100pF loading).
Subsonic Filter & Balance Control: If some records in your collection are a little worse for wear, the Duo's built-in subsonic filter will help to eliminate low frequency rumbles that can be caused by imperfections within your vinyl. Combine this with the balance control for handling potential cartridge imbalances in your record player (that can cause a difference between the left and right channels) and the result is a detailed experience with accurate soundstage.
1/4" Headphone Output: Enjoy the warmth of vinyl privately thanks to the Duo's front-panel 1/4" headphone output. Uniquely, Cambridge Audio integrated this headphone jack directly into the phono stage, so you can still enjoy your records when there's no option to play out loud. The integrated headphone output also means no need to turn on your amplifier just to power your headphones, resulting in a more eco-friendly listening experience. The headphone output has a dedicated rotary volume control knob on the front-panel of the phono preamplifier.
Note: Headphones with an impedance of between 32Ω and 600Ω are recommended.
Stereo RCA Outputs: The Cambridge Audio Duo phono preamplifier is outfitted with a set of gold-plated stereo RCA outputs to connect to the line-level inputs on your home receiver or integrated amplifier using a set stereo RCA cables (sold separately - see Accessories Tab).
Note: Do not connect the Duo to a "Phono Input" on a receiver or integrated amplifier.
Turntable Ground: If your turntable has a separate grounding lead then connect it to the Duo's ground terminal. This provides shielding to the arm and the sensitive circuitry in the turntable.
Detachable AC Power Cord: The Cambridge Audio Duo comes with a 58" detachable AC power which plugs into the back of the phono preamplifier and a AC power outlet or surge protector (sold separately).
- Max Power Consumption: 10 watts
- Standby Consumption: <0.5 watts
- Mains Inlet Voltage: 100-240V AC
Auto Power Down: The Cambridge Audio Duo has an Auto Power Down function. The phono preamplifier will automatically switch to standby mode after inactivity of 20 minutes.
Our Product Research Team
At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.
1 question already asked
1 answer There is a buzzing sound on this unit only when the line out jacks are connected to my CD input on my receiver. This buzzing sound also exists through the headphones when plugged in to the Duo. If I remove the line out jacks from the back of the Duo the buzzing in the headphones goes away. I am using an Audio Technica AT120 turntable set to "Phono" on the back selector and running the RCA outs along with the connected ground cable into the "MM" input on the back of the DUO. I have used 2 different RCA cables from the line out of the Duo to my Onkyo NR 656 and also used multiple analog inputs but nothing gets rid of the buzz. Does anyone have any suggestions on what the issue might be? [ ThePhilosopher Mar 18, 2018 ]
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. [ Krissy Mar 28, 2018 ] Staff