Cambridge Audio CXA81 integrated amplifier

During my tenure as a Stereophile writer, I've reviewed a lot of integrated amplifiers. The mostly moderately priced integrated machines I've reviewed have included the Heed Audio Elixir ($1195), Luxman SQ-N150 ($2795) and L-509X ($9495), NAD C 328 Hybrid Digital ($549), Octave Audio V 80 SE ($10,500), Rega Brio ($995), and Schiit Ragnarok 2 ($1799 as equipped). Regardless of price, all these integrated amplifiers engaged my senses and made engaging, dynamic, colorful music from LP grooves and ones and zeros.

Decades ago, integrated amplifiers were full-featured beasts—and then there was a move toward minimalism, at least at the higher end. Today, things have swung back again: With some exceptions, today's integrated amplifiers once again offer myriad extras. Today there's more to offer. In addition to the traditional phono stage and headphone jack of decades past, today there's Bluetooth, internal DACs, streaming, implanted mood-enhancer chips, and integrated cappuccino/latte/espresso machines—all at a competitive price point.

The Cambridge Audio CXA81 integrated amplifier ($1299) is a feature-rich machine. It doesn't have Ethernet, and it lacks a phono stage and coffee machine, but otherwise it offers everything popular with today's music- and hi-fi– loving suburban bon vivant: a built-in DAC that converts up to 32/38 and DSD256 (delivered via DoP) files and streams. It has an asynchronous USB input, the best kind. There's Bluetooth, which makes it easy to send music from portable devices, and because it's aptX HD, it even sounds good. There's headphone support and even mood enhancement, although it's the old-fashioned way: with music.

Measuring 16.9" wide, 4.5" high, and 13.4" deep and weighing just under 20lb, the CXA81 has a steel chassis and an aluminum face. It's supported in the rear by two footers composed of silicone rubber and ABS, and in front by a case-wide, ½" black-plastic ridge finished with a long rubber strip, which created the illusion that the CXA81 was floating above the shelf on my Salamander rack. It's a subtle but effective design element that suggests that thought and care were taken in the CXA81's design.

The minimalist front panel concentrates most of the controls—everything but the standby/on button, the 3.5mm headphone jack, and (thank you) the large volume control knob—onto an acrylic center window with backlit LEDs: Four analog source-select buttons labeled "A1" through "A4," a "Protection Indicator" light (which indicates clipping, over-voltage, overheating, or short-circuit), a button to toggle between A and B speaker options, a mute indicator, three digital source-select buttons marked "D1" through "D3," a tiny button stamped with the universal sign for USB, and that large volume control knob. Sharp eyes are required to read the labels. A universal remote—included—duplicates the CXA81's front panel controls, and then some.


The unit's back panel is smart: Each jack is labeled both above and below, making it easy to read from most angles. On the left side, there's an IEC power input followed by an RS232C connector, a pair of control-bus inputs (RCA), IR in, and one pair of trigger-out jacks, and two sets of speaker-binding posts with large, easy-to-grip plastic caps. On the right, there are digital inputs across the top: a Bluetooth antenna, a USB input, three S/PDIF inputs (one RCA and two TosLink). Farther down, there's a single subwoofer out (RCA), pair of pre-out jacks (RCA), four pairs of analog inputs (RCA), and two balanced inputs (XLR).


Inside the case, the CXA81 has an amplifier section that drives nominal 8 ohm speaker loads with 80Wpc and nominal 4 ohm speaker loads with 120Wpc, in class-AB. There's a remote control and unbalanced (RCA) and balanced (XLR) inputs; one does not often see balanced inputs at or near this price. It's "Roon tested," which just means that Roon tested it, and, like most DACs, it works with Roon. It doesn't have Wi-Fi or an Ethernet connection.

Cambridge Audio literature says the CXA81 has "separate, symmetrical left and right channels." Tony Stott, training and development manager for Cambridge Audio, elaborated via email: "It has symmetrical and separate transformer taps for the left and right channels, twin rectifiers, and separate PSUs for the power stages."

Stott described the improvements in the CXA81 compared to the original CXA80, which was introduced in 2014: "The analog signal path has been fine-tuned after meticulous and extensive listening sessions." Those listening tests were carried out, he told me, using PMC OB1 speakers. "The preamp section utilizes sound-oriented JRC op-amps. Tone controls have been bypassed, and both the signal chain and power supply have been upgraded with class-leading Wima, Rubycon, and Nippon Chemi-Con capacitors."

There's no phono stage, which is reasonable considering the CXA81's size and price. "Space was extremely tight, and there is no way to guarantee adequate results if integrating a phono stage."

"We recommend [Cambridge Audio's] Alva Solo ($179, MM) or Duo ($299, MM/MC) phono stages for a performance in line with CXA81 level," Stott said.

Considering the CXA81's modest price, I thought my 1957 Thorens TD 124 turntable with a Jelco TS-350S MKII tonearm ($799) and Hana EL MC phono cartridge ($475) would make a good match. The Hana's output was amplified and equalized by the Luxman EQ-500 phono stage ($7490), temporarily replacing my Tavish Audio Design Adagio Vacuum Tube Phono Stage ($1990). The rest of the system was either the Polk Audio Legend L100 or the Quad S2 standmount speakers (both currently $1195/pair), both supported by 24" Sanus speaker stands, BorderPatrol DAC SE ($1925), and an Asus laptop running Roon. Cabling included a Furutech GT2 Pro USB cable (3.6M GT2 Pro cable, $450), Auditorium 23 speaker cables, and Triode Wire Labs Spirit II interconnects ($339).

The lightweight, compact CXA81 slid easily into my Salamander Designs five-tier rack.

Cambridge Audio USA
1913 N. Milwaukee Ave.
Chicago, IL 60647
(877) 357-8204

Long-time listener's picture

As it turns out, I AM in the market for a good, mid-priced integrated (since the NAD M32, highly recommended by Stereophile, didn't work out so well). But my question is, if Accuphase, Luxman, NAD, and many others can offer tone controls in their much higher-priced integrateds, why can't Cambridge Audio? Their CXA-61 has them, but I guess as we go up in price, we get FEWER options. That's nice. Cross another one off the list.

JRT's picture listed on the Shiit website for $149, and might be a solution adequate to your need for parametric EQ tone control, but maybe not with this integrated amplifier, which I think trades away too much system flexibilty for that integrated functionality. Opinions vary.

Note that it has single ended I/O, so I would suggest relatively short interconnections and shared ground potential with the equipment attatched at the other end of the interconnections.

Long-time listener's picture

It's too bad it has to come as a separate unit, which means more cables, but it's interesting nonetheless. I'm not sure I like the frequencies where they have set the four EQ bands (20, 400, 2kHz, 8kHz), seems kind of odd to me, but I'd have to use it to see. For my purposes, a simple set of bass and treble controls, centered at around 80/100 Hz and 10Khz, usually accomplishes all I need, or else maybe a "tilt" control as I've seen on some amps.

JRT's picture

...Parasound Halo P6 2.1 preamplifier/DAC is good quality, includes your desired tone controls among a wide variety of useful functionality, and has balanced outputs to interconnect to monoblock amplifiers located near the loudspeakers. Nord Acoustics makes some good moderately priced Hypex NCore NC500MB monoblock amplifiers with balanced inputs.

JRT's picture

If you do order from Nord, you might want to add this £10 option for US support.

Long-time listener's picture

Will keep that one in mind for the future

Ortofan's picture

... tone controls and uses Hypex power amplifier modules.

SAllison's picture

This seems to be divisive. I see no tone controls as a big plus and am happy to see Cambridge get it out of the signal path. CXA61 also removed tone controls, it's the older CXA60 and CXA80 that had them.

Long-time listener's picture

... whenever possible, in which case I select "Direct" or "Tone Defeat." But the OPTION to use them can only be a good thing, providing a more versatile amplifier, and for me it's really necessary. I listen to such a broad range of music, with some recordings dating as far back as the 1930s, where a slight treble cut to reduce harshness or a slight bass boost to provide a more solid foundation makes the experience so much better. And out of consideration for my neighbors, I listen at low volume late at night, adding a bit of bass and treble for "loudness" compensation. Having tone controls on a unit doesn't hurt listeners like you, since you can bypass them, but leaving them off hurts listeners like me. It assumes you only listen to a narrow range of very well-recorded music from the last decade or two. Not the case with serious listeners.

partain's picture

Yea or nay ?

SimonK's picture

As I've experienced with all current Cambridge products, their speakers outputs have reversed polarity, so you need to actually go from minus to plus (black to red and red to black) to get the correct phase response. Cambridge has gotten somewhat of a reputation of being a tad laid back because of this - this is simply because they aren't when correctly wired. The CXA81 plays neutral and accurate. It is beyond me, why they don't inform their customers about this.

Jim Austin's picture

I realize I'm answering an older comment, but it's important to correct this. As you can see from the measurements included with this review, the Cambridge Audio CXA81 preserves absolute polarity.

Jim Austin, Editor

SimonK's picture

Hello Jim

Thanks for commenting and correcting. I just re-read the measuresments and it may very well do that, but the explanation to what I hear must be then, that the digital input is inverting the polarity as you measured. What would be the idea here? For my point of view it seems like you would have a polarity issue if using both analogue and digital inputs, so that you'd need to change the speaker outputs whenever you play from one or the other source.

SAllison's picture

Hi Jim, it looks like the digital inputs reverse polarity but analog inputs do not? Is that right?

Jim Austin's picture

their speakers outputs have reversed polarity, so you need to actually go from minus to plus (black to red and red to black) to get the correct phase response.

I'm truly not trying to split hairs here; rather, because of this phrasing, I simply wasn't thinking about the digital module. Yes, of course, it is true that the digital module is reversing phase.

Why would they do that? I'm only speculating, but I would guess it's a matter of convenience: It was easier to design the component that way, and to keep the design as simple as possible. Do keep in mind that while the audibility of absolute phase has been established with certain types of music, most recordings have mixed phase, and even in pure cases it's quite difficult to hear. A manufacturer could be forgiven for thinking it doesn't matter.

Jim Austin, Editor

SAllison's picture

Thanks so much for the speedy reply!

JackHuang's picture

I recently purchased a Cambridge Audio CXA81 amplifier and consulted the engineers at Cambridge Audio regarding this issue. They confidently denied the occurrence of polarity inversion when using data input at that time.


Thank you for contacting Cambridge Audio.

You do not need to reverse your speaker connections when using this device.

If you require any further information or assistance, please do not hesitate to let me know.


Thank you for your quick response and clarification about the speaker connections.

However, my original question also included a concern about the DAC in the CXA81. I heard that the DAC in the CXA81 may produce a signal with inverted polarity. Could you please confirm if this is accurate or not?

Understanding the polarity behavior of the DAC in the CXA81 is important to me, regardless of whether it requires any changes in the speaker connections.

I appreciate your assistance with this matter.


We are unaware of any reports regarding your question "I heard that the DAC in the CXA81 may produce a signal with inverted polarity. Could you please confirm if this is accurate or not?"
This is not something that we would expect the unit to do and if it did for some reason invert the polarity, and a reset did not resolve the issue then the unit would need to be sent in for inspection and servicing.

I connected my Mac to the CXA81 amplifier via USB and played a video from YouTube, Then, I lightly placed my finger on the bass diaphragm of the speaker and it seemed like I could feel the diaphragm pushing outward first during the "+" parts of the vedio, and then retracting inward during the "-" parts.

wozwoz's picture

I am fan of Cambridge equipment, and have one of their amps in a bedroom (not main audio setup) which is a very fine minimal classic design. Having said so, I would never purchase any amplifier that has Bluetooth built-in, (a) in part because I don't want to be needlessly radiated in my own home, and (b) because Bluetooth is a suboptimal typically compressed and lossy medium that is, in my view, inconsistent with the goals of hi-fi, and it disrespects the equipment to include such a format (leaving aside radiating your brain).

LogicprObe's picture

The review states that the amp has 'natural silicone rubber' feet.
No silicone products are 'natural'.
They are all man made.
Latex is the only 'natural' rubber product.
You can't believe anything from the marketing departments of these companies.

SAllison's picture

How does the CXA61 compare? On paper it looks like the same thing with no balanced inputs, less power and a slightly different DAC for $300 less. I wonder if there is anything significantly different in the measurements for the CXA61 model?

SAllison's picture

I just want to post that 33 ohm output impedance for the headphone jack is not low. Most quality, affordable headphone amps like the Schiit Magni and JDS Atom are below one ohm. 33 ohms is frustratingly limiting; I can use 250 ohm Beyers and 300 ohm Sennheisers and that's it. I suppose I could get away with flat impedance curve planars but power output will be limited.