Cambridge CXA81 MKII Amplifier Review

[AudioSceptic]

What I suspect may be a problem (not sure that the amp gain structure really works this way):

Typically, the internal DAC will play whatever it is fed digitally. There is likely no digital attenuation ahead of the DAC. Downstream there will be an analog attenuator (typically a digitally controlled array of analog switches aka electronic potentiometer) and then the power stage.

The risk is that whenever the digital input signal contains close to full scale signal (true for about 90% of today's pop music recordings), it will go into clipping.

Yes, if that is the case, but do we know?

 

[capslock]

Yes, if that is the case, but do we know?

As I said, I would be very surprised if an input signal coming in via S/PDIF or optical were attenuated by 2-3 dB to accomodate the screwed up gain structure. Anyone have a schematic? Or are there any hints in the user manual that one can set digital gain.

 

[DSJR]

It's a grand in the UK and what would 'we here' compare it with, as Naim is one of the only dealer alternatives that comes to mind - and we all know how that turned out for multiples of the price of this one being tested....

My local audio-salon recently took on Wiim and were quite surprised I think how good it was. No idea if they'll sell any, but they'll never in a million years earn a meaningful profit from this brand...

We really are spoiled here fellas, if we try to understand the figures and use the combined test results to aid decisions before the eye-fi and wallet-fi chimes in...

 

[kyuu]

Just gonna jump on the pile here: the issue with this thing is you can simply do better for much less these days, or get a lot more for the same price. AVRs in this price class measure as well or better while giving you more power and more channels, and of course all the video processing. Hell, a Wiim Amp at $300 gives you nearly as much power and measures about as well (excepting a bit of load dependency). A little box that says "Wiim" isn't as prestigious as a bigger one that says "Cambridge" though, I suppose

 

[Koeitje]

1.6 is about 2 dB less than 2.0. Would that make such a big difference?

Considering I'm right at the edge: yes. Because the scenario I described was with a digital source, I also have a non-digital source that doesn't reach 2V line-level output. With that source selected I can max the amplifier and still won't be too loud. So I do appreciate some headroom.

Don't really know why we are arguing about this on a product at this price level: it should simply be 2V and anything less is unacceptable.

 

[VientoB]

The fact that this is a revision that did not fix the problems seems unacceptable to me.

 

[Spkrdctr]

I agree with others on here. They revised the unit and didn't fix anything. I can't imagine what they think they revised! So again, as happens here on ASR we find a tested piece that tests fair to ok, but the price is too high for what you get. The unit can be EASILY fixed if Cambridge has the desire. They could fix any DAC issues AND even add more power. None of this is rocket science. It is old science that has been around for a quite a few years now. It is like no one in a lot of these companies is telling their engineers to build to a spec. Spec more power and a much nicer DAC and then your done. Then you can charge over $1000 dollars and have it be a good value. As it is, at $1000 you are NOT getting your money's worth as many have pointed out. So I had to give it a poor ranking. Overpriced and under delivering. So close to making the bar and missed.

 

[DearSX]

I had a version of this unit for a trial. It sounded fine to me. I liked the look and style of the device, but not the price. Happy with my WiiM Ultra, hope it gets tested soon too

It's not any more powerful than a WiiM Amp! Those Audiophonics Class D amps looking better everyday too!

Thanks for the review Amirm!

 

[AudioSceptic]

Considering I'm right at the edge: yes. Because the scenario I described was with a digital source, I also have a non-digital source that doesn't reach 2V line-level output. With that source selected I can max the amplifier and still won't be too loud. So I do appreciate some headroom.

Don't really know why we are arguing about this on a product at this price level: it should simply be 2V and anything less is unacceptable.

Hey, I'm not arguing, just wondering how critical some measurements are, and I do think the DUT is not good value.

 

[AudioSceptic]

I had a version of this unit for a trial. It sounded fine to me. I liked the look and style of the device, but not the price. Happy with my WiiM Ultra, hope it gets tested soon too

It's not any more powerful than a WiiM Amp! Those Audiophonics Class D amps looking better everyday too!

Thanks for the review Amirm!

Also look at the Fosi V3.

 

[audio_tony]

So much focus on the 1.6v pre output, but does it really matter?

Most buyers of this amplifier are not buying it to use as a preamp are they? And when they upgrade, they will likely sell this amp and spend the money on a pre / power combo anyway.

So IMHO it's irrelevant.

 

[kyuu]

So much focus on the 1.6v pre output, but does it really matter?

Most buyers of this amplifier are not buying it to use as a preamp are they? And when they upgrade, they will likely sell this amp and spend the money on a pre / power combo anyway.

So IMHO it's irrelevant.

Maybe. But the question is why, on a $1000+ stereo amp, they couldn't manage it. This isn't a budget product where this would be an understandable corner to cut to meet a price point. If you're going to put pre-outs on an expensive product, seems like they should try to do a decent job of it. Might even be a good point of differentiation against cheaper amps?

 

[ryanmh1]

I have a slightly different take. I've always thought Cambridge generally did a better job than a lot of "high end" or "high end adjacent" companies. Less noise, less distortion. That's true here too. I am not sure how the DAC performance was allegedly measured, since there is no DAC output. You cannot actually measure the performance of the internal DAC absent a pair of outputs coming straight off the DAC. That's like claiming to measure the voltage gain stage of an amplifier when all you have are speaker terminals. You can't. There are multiple stages and "components" all effectively wired in series, one of which happens to be a DAC. No kidding a standalone cell phone DAC might measure better. It's a different animal.

What the Cambridge does manage to do is handily beat the standard "good enough" integrated amp distortion level of .015% THD+N, 1W 8ohms. It's quiet. 10dB quieter than the norm for the product class, if you have any familiarity with general measurements for the product class. What it also has is sufficent open loop bandwidth and feedback to work properly. Did Doug Self give some input to Cambridge at one point? Yes, and this is perhaps evidenced to a degree in that the 15kHz THD stays around .015% or less. It doesn't rise to .2% or some other obscene figure like many "high end" products. Not even .05%. It's wicked good and beats a lot of Hypex amps on this measure.

Also, for something with a traditional linear power supply, the 1kHz THD+N is also very, very good. The very best products out there can only manage about .0025% or so with 1W into 1kHz at 8 ohms, e.g. a McIntosh MC462. This isn't that far off. It's what, .005% or so? That's remarkably good for a $1000 product with a linear power supply. Personally, I prefer to avoid switching supplies. The noise performance can be great, but the linear supply has its own set of benefits which are too often ignored here.

As for the preamp outputs--seriously? It's just distortion from the power amp clipping. And it still does drive 2V cleanly and with very low noise, just with slightly more distortion on those last 3dB than it will drive 1.6V. Inaudible, since the speaker distortion is through the roof by that point. Plus, rarely if ever have Hypex based products been savaged here for not reaching full output at 2V. So why is this product savaged for the inverse? Buy an amp you can drive to full output with 1.6V if you want to use this as a preamp and insist on not having .03% distortion. Same advice might be given to people trying to drive a Hypex with this thing: Buy something else to drive it. Which product is "broken"? Either none or both, pick your poison.

Honestly, companies should just start removing preamp outputs entirely to avoid criticisms like this. That's one way Cambridge could have "fixed" it in V2. I see lots of criticism that this is V2 and Cambridge did not fix this despite ASR telling them to. Well, think about that. Why don't they care and why didn't they just pull the outputs? Because ASR is irrelevant. Preamp output voltage in an integrated is a minor issue. But they get savaged for that and everything else that ain't on top of "the chart" because they are selling a product with a traditional linear power supply. That will always get savaged at the home of the SINAD drag race. Manufacturers don't give two whits what ASR or anyone here has to say about a darn thing, outside of a handful of ChiFi manufacturers and Hypex integrators who see opportunity since they've got that 1kHz THD+N licked in their stripped down, offbeat products, often with usability and quality issues galore. And that's a really, really unfortunate but understandable thing. Even Cambridge, which offers one of the best measuring low cost, linear power supplied integrated amplifiers, ain't immune from the "IT SUCKS. DON'T BUY. TOPPING/AIYIMA/BENCHMARKS MEASURES BETTER AND U CAN GET THEM 4 PENNIES!" ASR guillotine. I think part of the reason many companies including Cambridge don't care about ASR criticism is because the site continues to insist on, as its calling card, its THD+N at 1kHZ drag race, and does little more than measure a product and proclaim it good or bad, with a very cursory look at the product (if any) in actual use, often followed by dismissive comments and commentary that "Product XYZ sucks because it's not as good as a cell phone DAC and 10dB worse than a $4000 pro audio product that measures way better..."

Behaving as ASR and its denizens tend to behave is not a way to be taken seriously by manufacturers. It's a way to be sure they ignore you, which by and large, they do. This is a "no win zone" for an outfit like Cambridge or NAD, not to mention higher end manufacturers. So, perfectly valid criticism falls on deaf ears. Unfortunate, but understandable. Stereo Review, which is what ASR tries to be the modern incarnation of, at least didn't proclaim every product that doesn't meet some weird, unknowable scientifically and audibly irrelevant "standard" to be an overpriced POS not worth buying and a bad value. That's not that ASR should change its ways. It is what it is, and after this many years, is not likely to change much.

But I digress... Cambridge may not care about ASR, but that's because of the arguably unfair conclusion. Cambridge gives you an integrated amp with a warranty from a reputable company with a linear power supply that will last for decades, and vanishingly low levels of distortion and noise for about a grand. It's a beautifully made product that would give anyone some pride of ownership. And you get a DAC that seems to not degrade performance of the amp's SNR and a free set of voltage-limited preamp outputs to boot. That's a fair takeaway, but that's not what anyone here is saying. Everyone thinks it sucks. Funny thing is, in its product class, it performs quite spectacularly, really, with one foible that is so minor it is hardly worth mentioning. Who hooks a power amp up to a stereo integrated amplifier, anyway?

 

[Doodski]

and a free set of voltage-limited preamp outputs to boot.

It's not free. It is bought and paid for by the buyers of this product.

 

[audio_tony]

Maybe. But the question is why, on a $1000+ stereo amp, they couldn't manage it. This isn't a budget product where this would be an understandable corner to cut to meet a price point. If you're going to put pre-outs on an expensive product, seems like they should try to do a decent job of it. Might even be a good point of differentiation against cheaper amps?

It's not that they couldn't manage it. They didn't need too. Why would they bother when they know that the upgrade path is likely to be a separate pre /power, and (for them) hopefully their own products.

This is all because of the obsession (on this site in particular) with sinad. But realistically it's going to be inaudible.

 

[kyuu]

It's not that they couldn't manage it. They didn't need too. Why would they bother when they know that the upgrade path is likely to be a separate pre /power, and (for them) hopefully their own products.

This is all because of the obsession (on this site in particular) with sinad. But realistically it's going to be inaudible.

Ok, fine. But then why include the pre-outs at all if they are irrelevant? And again, why even buy this when you can get similar or better performance for much less money? If you're going to push the "but it's inaudible" angle, that necessarily asks why should anyone buy this rather expensive (for its class) product?

 

[pseudoid]

They just fight for market share with marketing and distribution.

Thank you for the review, as always!
I am feeling like a conspiracy theorist but I am not certain that it is unwarranted.

What is it with these established audio manufacturers peddling in hardware that are no better performers (mediocre by today's standards) than they were 25 years ago?
Is there a collusion -between these companies - to keep the specs deflated while inflating the prices.

 

[VientoB]

I have a slightly different take. I've always thought Cambridge generally did a better job than a lot of "high end" or "high end adjacent" companies. Less noise, less distortion. That's true here too. I am not sure how the DAC performance was allegedly measured, since there is no DAC output. You cannot actually measure the performance of the internal DAC absent a pair of outputs coming straight off the DAC. That's like claiming to measure the voltage gain stage of an amplifier when all you have are speaker terminals. You can't. There are multiple stages and "components" all effectively wired in series, one of which happens to be a DAC. No kidding a standalone cell phone DAC might measure better. It's a different animal.

There are pre-outs. Presumably it uses the DAC's digital volume control.

Also can you tell us what the "mkII" brings to the party?

Like it or not ASR does influence a lot of buyers, and Cambridge Audio and NAD will be keeping a close eye on these reviews as it will affect sales, now that we're in the age of very competent competition from Chinese manufacturers.

 

[amirm]

What is it with these established audio manufacturers peddling in hardware that are no better performers (mediocre by today's standards) than they were 25 years ago?
Is there a collusion -between these companies - to keep the specs deflated while inflating the prices.

Measured performance was king in 1970s and 1980s. Every company/engineer would as a result compete for lowest noise and distortion. They would show circuit design, component choices, etc. I used to love reading those brochures!

Consumers let the above slide to the point that it is now the norm, even among traditional audio companies to not care one bit about measurements. They don't even show such in their specs! Take the 1.6 volt before saturation. If they said this in the spec it would be one thing. But there is no mention of it, leaving it to someone like me to discover it. As a result, I suspect no one is rewarded in the company for producing highest fidelity gear.

 

[Scytales]

It was a device designed to power amps with low input sensitivity. But when you have an amp whose input sensitivity is between 0.775 volts and 1.6 volts, very very common cases in domestic hifi in RCA connection, your preamp having 10 volts or more output becomes a problem for daily use. 'it has a track potentiometer: the level adjustment will be done at the very beginning of the potentiometer's travel and moving it by one millimeter will increase the level too much or decrease it too much, not to mention the imbalance between tracks which is often significant at the start of the track. And all this because of the line output level of the sources which is typically 2 volts...

You, restorer-john and DSRJ have just had a very sensible exchange about that matter.

I would add that some German hi-fi magazines used to do, and in certain cases still do to this day, measurement of THD, IMD and signal/noise ratio of preamp at lower output levels (from 30 mV to 300 mV) with input voltage standardised at much less than 2 V. Those are closer to actual nominal levels in a typical hi-fi system.