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Review and Measurements of Cambridge DacMagic Plus

amirm

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#61
How much time does it take comparing to USB jtest ? Is it time consuming ? If it's not, maybe we could have a voting whether it is equally important to members and whether it should be included in following reviews ? (of course if you are willing to do it)
Everything is time consuming. It is not just the test but post documentation and reporting here. The focus of my testing has never been to test everything. I test enough to give us confidence in engineering quality of a device. If some additional test is needed, members can ask and I will run them.

All new tests comes at the expense of testing other gear of course. This specific DAC was sent to me back in November of last year! The owner also has sent me a phono preamp to test which more testing delays that evaluation.
 

BYRTT

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#62
Is your guess that IIR filters were used with ES9018 because there was not enough processing power to use FIR?
Haven't looked up any ES9018 datasheets because they used to be of more or less secret to users : ) so can only speculate that either chip has maybe only one filter that is more and less easy or cheap to setup or it probably has much more filters but manufacture picked his favor for whatever one or the other reason. Guess after we entered digital era weird stuff from normal can show up here and there down the road without marketing or datasheet transperence for example have a U7 DAC that if used with most new build of drivers for MS Win sound system it will add 3 times 360º phase shift as was it a 3 way 4th order IIR filtered speaker and how about that : ) to get over that one has to use the older driver build or use ASIO and in first place to know about that phaseshift one has to measure unit, also how weird was it see that crazy huge phaseshift for a Lyngdorf unit in bypass or non active mode shared by a German user deep into think it was the acoustic Lyngdorf thread.
 
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amirm

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#63
Here is Toslink comparison to USB:
Cambridge Audio DacMagic Plus Toslink Jitter Measurements.png


Performance is tiny bit worse with Toslink. Noise floor is a bit higher, there are a couple of tones on each side of our main signal at 12 khz. And some power supply spikes down low:

Cambridge Audio DacMagic Plus Toslink Jitter Zoomed Measurements.png


Nothing audible so use whichever is needed/convenient.
 

Krunok

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#64
Everything is time consuming. It is not just the test but post documentation and reporting here. The focus of my testing has never been to test everything. I test enough to give us confidence in engineering quality of a device. If some additional test is needed, members can ask and I will run them.

All new tests comes at the expense of testing other gear of course. This specific DAC was sent to me back in November of last year! The owner also has sent me a phono preamp to test which more testing delays that evaluation.
Is your analyzer capable of measuring phase shift of the DAC like the ones shown by @BYRTT? If yes, maybe it would be worthwhile to consider replacing some of the standard tests you run on DACs with the phase shift measurement as that one can potentially have serious impact on SQ.
What do you think?
 

amirm

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#65
Is your analyzer capable of measuring phase shift of the DAC like the ones shown by @BYRTT? If yes, maybe it would be worthwhile to consider replacing some of the standard tests you run on DACs with the phase shift measurement as that one can potentially have serious impact on SQ.
What do you think?
I don't believe in audibility of such phase shifts. That aside, for some odd reason the analyzer is setup to measure differential phase shift between channels, not from input to output. With analog products (e.g. amps) I can trick it into measuring the input to output but not with digital sources.
 

amirm

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#66
Here are the headphone measurements. First, at 300 ohm:

Cambridge Audio DacMagic Plus Headphone at 300 Ohm Measurements.png


This is actually pretty decent. 71 milliwatt is below my 100 milliwatt standard but should still be good.

33 Ohm load likewise is not very powerful:

Cambridge Audio DacMagic Plus Headphone at 33 Ohm Measurements.png


The reason for this one is the high output impedance:

Cambridge Audio DacMagic Plus Headphone Output Impedance Measurements.png


So with care you can use it but you need to be aware of its limitations.
 

Krunok

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#67
That aside, for some odd reason the analyzer is setup to measure differential phase shift between channels, not from input to output.
Obviously design engineers considered phase difference between channels more of an issue than phase shift between input and output. :D
 

graz_lag

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#68
Here are the headphone measurements ...
So with care you can use it but you need to be aware of its limitations.
For what reason those premium brands do not finish the job ?
There is always some unfinished feature, here or there, that jeopardize a bit the overall package.
 

amirm

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#69
For what reason those premium brands do not finish the job ?
I think back in 2011, there was not as much awareness of output impedance. Or the serious headphone audiophile community that exists today. So people did what they used to do which is to put a resistor on the output and with it, gain output protection, ease of design, etc.
 

amirm

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#71
Does the high output impedance affect the whole frequency range or only certain parts?
It can impact any part of the frequency response that has a corresponding lower impedance. Planar magnetic drivers tend to have a rather flat resistive load so they just lose power, not their tonality.
 

tired_guru

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#72
If 10 years old product is so immune to jitter & produces such great measurements even when using toslink, it shows exemplary engineering, know how & years of research. This makes me wonder how quite new, ultra cheap Dacmagic 100 from CA would perform. I can have it locally for less than 150$ brand new. Even though it is small and looks cheap, it has quite complex digital section inside.
 

pma

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#73
Dacmagic 100 measures worse. Dacmagic Plus is wisely well engineered product. Look at the circuit diagram, it tells most.
 

restorer-john

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#78
Indeed, particularly thanks to the '80s output "gentle" slope filters to reduce phase shift in the audible frequencies.
There was nothing 'gentle' about the filters used in 80s CD players. This is typical (conceptually) of early 16bit 44.1K implementations.

filter01.jpg


filter02.jpg

Reference: H. Nakajima. 1979. Digital Audio Technology.

From my experience, Murata (of ceramic filter, MPX and resonator fame) manufactured a lot of these costly filters in early CD players. Each were carefully slug-tuned by hand for every pole, a time consuming and expensive process.

The Philips 4x O/S 14bit system (176.4KHz) allowed the use of much fewer and cheaper, filter components, and the oversampling money saving game was on.
 
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#79
I have a soft spot for Cambridge Audio products. They are extremely well built and loaded with features and capabilities, especially given their price points (compared to other hifi brands). The DACMagic+ has always been on my radar, but due to it using what is considered pretty outdated technology nowadays, I never seriously looked into it. Seems like it still is a strong contender today. I recently sold my Cambridge Integrated Amp and CD player, and a little sad I got rid of it. Their integrated amps have quite decent Class A standalone headphone amps in them.
 

m8o

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#80
I own two of these; one in black and one in silver. This test is proof to me that measurements only go so far. While the M51 test showed far more 'anomolies' than this [tho, with notably higher SINAD at least], I can strongly affirm that when source is a cable box to> 50 foot hi speed HDMI to> M51, it far out resolves the same cable box to> short TOSLINK to> DacMagic+ to> 50 foot Mogami cables to the same amp & headphones as previous. ;)
 
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