Cambridge Audio's "Duo" Phono Preamp/Headphone Amplifier Outperforms Its Low Price

Cambridge Audio's Duo is a compact, attractive, lightweight (2.1 Lbs) low priced phono preamplifier that will surprise you with its solid sonic performance as well as its low price. It certainly surprised me! It also features a headphone amplifier so it makes for a great desktop or dorm room accessory.

The back panel features separate MM and MC inputs as well as a balance control, which is somewhat unusual but a nice feature for headphone listening. There's also an IEC jack for the built-in switch mode power supply instead of an outboard "wall-wart" type supply and a ground lug. Cambridge identifies the back panel jacks from both above and below, which is something I wish all manufacturers would do. That allows you to read from above as well as identify what's what even with cables connected. The front panel features a "standby/on" button, a MM/MC selector, the large center-mounted volume control and a 1/4" headphone jack. The (defeatable) standby mode switches off the unit after 20 minutes of non-use.

Cambridge chose to keep things simple by offering no MC loading options, instead fixing it at a sensible 100 ohms, with gain fixed at 60dB. MM load is 47kOhms/100pF with 39dBs of gain. RIAA accuracy is spec'd at± 0.3dB 30Hz-50kHz. Signal to noise ratio is >90dB (MM) and >70dB (MC). The overload margin is a healthy>30dB with recommended MC cartridge output range of .3 to 1mV.. THD+noise 1kHz (20Hz-20kHz) is <0.0025% (MM) and<0.02% (MC). Crosstalk (at 20kHz) is rated at >85dB (MM) and >75dB (MC). There's also a built-in, non-defeatable subsonic filter, (-3dB@12Hz 6dB/octave) which at this price point makes a great of sense considering the likely turntable to be used with such an inexpensive phono preamp. Oh! The price: $299.00.

Careful readers might have guessed something around that amount based upon the MC crosstalk measurement of >75dB as well it being measured at 20kHz but I suspect even the most careful listener would never guess the price based solely upon listening.

The Duo is surprisingly quiet. Even with the volume cranked well beyond normal listening levels hiss was impressively low. I chose to pair the Duo with Rega's exciting new P8 turntable that came with the lower cost ($795) Aria MC cartridge that outputs .35mV with a suggested 100 ohm load. I also chose to play only records I'd never before played including a just unearthed (from my back hall record rack) "1841 Broadway" copy of The Best of John Coltrane (Atlantic SD 1541), Volume 2 of Yuko Mabuchi Trio (Yarlung YAR 71621-161V), which was kind of cheating since I'd already auditioned the sonically stunning Vol. 1 and Chasing the Dragon's live double album Vivaldi In Venice (VALLP008). I played some rock too but I felt I'd get a better idea of the Duo's sonic capabilities using acoustic music.

Simply put: the Duo was a more than pleasant surprise, producing a generously sweet sonic picture that was well-extended from top to bottom, midrange-neutral and that honestly presented all of the acoustic instruments—all in front of a commendably quiet backdrop. Imaging was reasonably solid and soundstage depth was particularly good though for more you'll get wider, deeper and especially taller.

All of the sins committed by this budget phono preamplifier were acts of omission but so evenly accomplished that they were only identifiable when the same records were played through a far more expensive phono preamp and cartridge. Bass was not soft and/or thin and the top end was only slightly brittle and even that was only occasionally. Nothing annoyed and all that was there could be enjoyed.

The headphone amplifier sounded equally sweet and pleasing though the gain only moderate. The more difficult to drive AKG 701s never achieved sonic "lift-off" but the Duo's output well-suited a pair of Grado SR60s. You could give the Duo to your kid and never worry that he'll blow out his ears listening to it, which is an attractive selling point!.

Pair the Duo with a budget 'table and a pair of easy to drive headphones and send it off to your kid's dorm room or use it in your home office or as a starter phono preamp in a budget system and it will keep you satisfied until you are ready to take a big financial leap upward. Until the vinyl resurgence made it possible, I don't think any company would have invested the time, expertise and money to produce a fine performer like this (made in China), package it so attractively and sell it for $299.00.

Without a stack of competitive units on hand I can't say how the Duo compares to other similarly priced phono preamps (with and without a headphone amp) but I can say if you are looking for a budget priced MM/MC phono preamp that includes a headphone amp, I can't imagine anything for $299 could sound much better.

COMMENTS
Drummer's picture

Cambridge CXC CD transport has the same 'upside down' labeling on back panel. It was a happy moment noticing that! Labeling on the case top is good too, something I owned used to feature that. Nice review. Thanks.

vinyl1's picture

MC cartridges require a wide range of loading. If I was aiming for the 'average' MC, or a compromise load, I would have picked something like 300-400 Ohms.

Hergest's picture

I agree. I find 100 ohms which tends to be the common 'standard' is too low. For myself I would much rather 470 ohms as that's the loading I've preferred with the majority of cartridges I've owned over the years.

Michael Fremer's picture
I'm in the 100 ohms camp
foxhall's picture

Seems like a really smart product in terms of strategy.

rl1856's picture

I am not 60 and I have about 2k albums.

I recently held a pop up record sale (garage sale for millennials) and most buyers were under 40, with a large number under 30....

Vinyl is growing.

Products like this will nudge more than a few Crosley owners along the upgrade path.

Keen Observer's picture

"non-defeatable subsonic filter,...considering the likely turntable to be used" -- warped disks can produce plenty o' subsonics, no?

Crazy Dave's picture

The Cambridge looks like a nice product. If I ever decide to replace my Hafler 110, I will consider it. Right now, I'm still pretty happy with the Hafter in this role.

Neward Thelman's picture

Dear Mr. Fremer:

"I [...] chose to play only records I'd never before played...".

I question your strange testing methodology, which I don't recall you employing in your previous reviews. By using sources that you've never heard before, you'd have no frame of reference. Having never heard the items you chose to use as your test sources, you could have no idea whether, for exmaple, the brittle top end that you 'sometimes' heard was a product of the preamp or the recording itself.

It's akin to evaluating equipment in unfamiliar settings; you may only get a gloss on the sound, rather than reaching review-worthy conclusions.

And, of course, a highly experienced professional such as you would have a deeply intuitive understanding of equipment review protocols, with no need for postings such as this.

On a related matter, you recently reviewed the Schiit Mani. It's been extremely well received in some quarters. Perhaps you could conduct a comparison between the Mani and the Cambridge unit.

Zardoz's picture

I often will do that with new equipment or with some other tweak to my system. I find that new material doesn't matter. If the system sounds right, it sounds right with whatever you play, be it new or familiar lps. Now I would never only play ONE new lp, but I can get a sense of what's going on by listening to a variety of any music. Just my two cents, YMMV.
Good listening,
Z

Michael Fremer's picture
The Mani was reviewed here by AnalogPlanet readers as part of a "blind" comparison of a number of phono preamps.
malco49's picture

i have been listening to vinyl on (starting in the mid 60's) off- didn't listen from say late 80's- late 90's and have listened since (never didn't own a TT). just want to say i have some Cambridge Audio in my stereo CD player AZUR 640C and amp AZUR 540A with a built in phono stage and thing they do a good job in my "budget" sei up!

prettyyoungtunes's picture

Hi Michael,

Thanks a lot for this review!
Would you recommend this product vs. the Shiit Mani?
Thanks
Best,

Michael Fremer's picture
And the Mani no longer here. You should search under phono preamps for the comparison story where readers could stream the same tune using a variety of phono preamps and choose "blind" which they preferred. Interestingly the vote was well in favor of an inexpensive phono preamp (under $100)
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