Cambridge CXA81 MKII Amplifier Review

[SAV1972]

I had a CXA-80 amplifier. I do not recommend purchasing.

 

[Haskil]

I had a CXA-80 amplifier. I do not recommend purchasing.

Wuy ?

 

[SAV1972]

Wuy ?

Poor acoustic control in the low frequency region. Low power. The DAC is made according to the residual principle. Overall I didn't like the sound. P.S. Sorry for Google translate please

 

[damirj79]

If one read the ES9016 datasheet entirely, it is obvious that the 3 Vp-p (which translates to 1,06 V RMS) apply to each phase (+ and -) of a pair of differential output. That means a differential output voltage (between each phase) of 2,12 V RMS. It cannot be otherwise since the output voltage of each phase is defined by about 0.92x the analogue power supply AVCC, which is recommended to be 3.3 V DC in the condition of measuring the performances stated in the datasheet.

I did, but.. this does not really clears the mess in the first place. 3Vpp is 1V RMS. You can then use inverted output or not, it depends on the design. If you do, then you have to sum both outputs because relative to noninv and inv outpust you do have 6Vpp.

 

[LTig]

I'm too lazy to look at the precise measures, but won't it reach 1.6V+ internally while feeding the power amp stage? Odds are that the DAC is dragging down the performance in that case.

I don't know the schematics, but expect that the DAC output feeds the volume control, so.as long as you keep the volume low enough to not exceed 1.6V at the preamp output all is good.

 

[Mart68]

Giving manufacturers credit where credit is due and not unduly chastising them for edge cases is, in my view, key to building credibility and influence with them, which I think helps the cause.

It's up to the manufacturer to build credibility with we, the customers, not the other way around.

ASR does not need to build credibility with Cambridge Audio. ASR is not trying to sell product to them.

Their 'listening trials' thing is an embarrassment to them. They could have saved costs on that and just delivered a better measuring product for the same money.

 

[Scytales]

I did, but.. this does not really clears the mess in the first place. 3Vpp is 1V RMS. You can then use inverted output or not, it depends on the design. If you do, then you have to sum both outputs because relative to noninv and inv outpust you do have 6Vpp.

It has cleared the fact that the THD+N and dynamic range of the ESS ES9016 is specified at 2 V RMS output with 0 dBFS digital input. Amirm just took a shortcut in the message you originally quoted in order to ask for clarification..

 

[capslock]

I think we are barking up the wrong tree(s).

1. The ES9016 seems to be voltage out according to the app diagrams in its datasheet. So the actual voltage will depend on the choice or resistors in the I/V stage.

2. Where does the saturation happen?

- Does it happen in the I/V / filter stage at the DAC output? That would be bad because it will be in the signal that gets amplified by the power amp, no matter what the setting of the analog attenuator is (unless the amp uses digital attenuation in the DAC).

- More likely, the preamp out is taken from the signal after attenuation and before it goes into the power amp. Likely, there is a buffer stage. How can a buffer running from at least + / - 5V, more likely + / - 12 V or higher, saturate at 2 V?

 

[taotone]

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?

100% agree.

Getting marked down so harshly for an edge case is unfair and misses the point of this amplifier.

Almost no-one who buys this amplifier will use the pre-outs. The use case is simple, add a streamer, perhaps an optical input from a TV, perhaps a CD player, a turntable and attach a pair of speakers. To be deployed into a med/small UK living room. Its predecessors have done that job very well for years, and this will continue to do that job with a slightly upgraded DAC.

99% of the 1% who actually use the pre-outs will be using them for adding sub(s).

Is it too expensive? Well, it's easy to get hold of, retains its value reasonably well, sounds good, looks good, comes with a decent warrantee, will often be discounted heavily with speaker packages, etc. It's middle-of-the road hifi and most people who buy it will be very happy with it.

I have never bought one, and nor would I. It's not aimed at the ASR crowd, but it's absolutely fine for what it is.

 

[rank]

Thank you very much for the review, very much appreciated. I rated poor because the price is totally crazy for a simple stereo integrated of barely 70W. In addition I use an AES/EBU input (except of course for multichannel SACD/DVDA & BRD) and here there is none.

 

[capslock]

100% agree.

Getting marked down so harshly for an edge case is unfair and misses the point of this amplifier.

Almost no-one who buys this amplifier will use the pre-outs. The use case is simple, add a streamer, perhaps an optical input from a TV, perhaps a CD player, a turntable and attach a pair of speakers. To be deployed into a med/small UK living room. Its predecessors have done that job very well for years, and this will continue to do that job with a slightly upgraded DAC.

99% of the 1% who actually use the pre-outs will be using them for adding sub(s).

Is it too expensive? Well, it's easy to get hold of, retains its value reasonably well, sounds good, looks good, comes with a decent warrantee, will often be discounted heavily with speaker packages, etc. It's middle-of-the road hifi and most people who buy it will be very happy with it.

I have never bought one, and nor would I. It's not aimed at the ASR crowd, but it's absolutely fine for what it is.

Are we sure it is just the preamp out that saturates? The preamp buffer and the poweramp would typically get their signal from the same point, probably the output of the analog attenuator. Coming to think of it, if this is an IC that has a single 3.3 or 5 V supply, I can see why it would saturate.

 

[NHL99]

The history of CA is interesting, company saved by dealership chains. Claims to be the first consumer amplifier with torodial.

 

[peng]

Are we sure it is just the preamp out that saturates? The preamp buffer and the poweramp would typically get their signal from the same point, probably the output of the analog attenuator. Coming to think of it, if this is an IC that has a single 3.3 or 5 V supply, I can see why it would saturate.

They all do at some point, but the test results did not show it at 1.6 V. It is just Amir’s way, others would not have considered it “saturats” at 1.6 V. In fact, not even at 2 V in this case.

 

[Koeitje]

I don't know the schematics, but expect that the DAC output feeds the volume control, so.as long as you keep the volume low enough to not exceed 1.6V at the preamp output all is good.

That means your power amp needs enough gain, which is not always the case.

 

[Haskil]

That means your power amp needs enough gain, which is not always the case.

But this is almost always the case for high fidelity power blocks having only an asymmetrical input...

 

[peng]

But this is almost always the case for high fidelity power blocks having only an asymmetrical input...

You can calculate the highest pre out voltage you need if you know the maximum spl you need at you seating distance, the full specs of your speakers, and the gain of the power amp you have or want to have. Many of us on ASR can calculate it for you if you provide the required info.

 

[Haskil]

You can calculate the highest pre out voltage you need if you know the maximum spl you need at you seating distance, the full specs of your speakers, and the gain of the power amp you have or want to have. Many of us on ASR can calculate it for you if you provide the required info.

Thanks, I don't need anyone to calculate that for me. CF the discussions above and the publications of @restorer-john who gives quite a few examples.

 

[amirm]

Getting marked down so harshly for an edge case is unfair and misses the point of this amplifier.

I did not harshly rate the unit and certainly not just for the 1.6 volt limitation. It was collective measurements of the DAC which showed many areas lacking refinement. The collective results were "meh" for me and that is the overall rating I give it. A stereo, dedicated product to music, needs to do better than an AVR and it didn't. Much like a lot of its competitors. So some pressure is merited to lift the standard by which these companies design against.

 

[amirm]

You can calculate the highest pre out voltage you need if you know the maximum spl you need at you seating distance, the full specs of your speakers, and the gain of the power amp you have or want to have. Many of us on ASR can calculate it for you if you provide the required info.

No consumer needs to start calculating anything. We need proper standardization here instead of wild west of gains we have now. Worse yet, such is not even documented.

In our world, hundreds of products have support for 2/4 volt as a source. We need to get the rest of the industry that is ignoring this transformation to pay attention and snap to this de-facto standard, which ironically was established by Sony/Philips some 40 years ago!

 

[Scytales]

It must be said that although Sony and Philips established the de facto standard of 2 V RMS max at CD player output which was endorsed by the ITU (with a broad +/- 3 dB tolerance) for consumer digital audio devices, during almost all of those same 40 years time period neither Sony nor Philips actually produced audio devices that comply with this standard. Till very recently, input sensitivity of analogue inputs on Sony's or Philips's appliances I know of remains in the vicinity of 150 mV to 300 mV RMS for full output (for preamp or integrated) and around 1 V RMS for power amp.

I just see that a current Sony multichannel receiver (TA-AN1000) specified 500 mV input sensitivity, which is better suited to high level line output sources, but even that remains remote from the ideal.

It must also be stated than nobody in the audio or hi-fi industry seems to really care for ITU standards applicable to consumer devices. It seems to me that the industry cannot regulates itself very well for that kind of things and that mandatory regulations by state institutions and proper enforcement would be the only way to achieve any standardisation of input/output levels.