Upgraded AK1499EQ DAC: Why Some Red Book CD's are Not Affected w/Upgrade?

[LanceLewin]

Happy Spring, everyone!
Just completed a very precise A/B test with new DAC built around a AK1499E/Q chip combo, and my
older Marantz SA8005 w/ CS4398 w/low jitter dual clock? Several old CD's seem unaffected with
the upgrade from the CS4398, while others' showed a pronounced difference
(e.g., sound-stage depth, better articulation). Why? Thank you.

Lance
Georgia, USA

 

[VintageFlanker]

Just completed a very precise A/B test

You will need to give more details about this first.

 

[Shorty]

 

[Chrispy]

What are the details of the "precise" AB testing, tho?

 

[MaxwellsEq]

Just completed a very precise A/B test

You misunderstood @VintageFlanker question. Please describe how you ensured that levels are correctly matched to .01V and you are unable to know which DAC is being used.

 

[oleg87]

sound-stage depth, better articulation

As always, the first suspect when people bring out descriptors like this, which are much more easily accounted for by the brain's "signal processing" than a converter's nonlinearities, is simple placebo effect.

 

[sonitus mirus]

Though I understand your wanting to know how I A/B tested ... if the aforementioned CD's, that did not show any differentiating-effect between the AK1499 and the CS4398, but other CD's clearly did, how is this possible? All things being equal, including Volume setting and Seating position, I was able to make these determinations.

My test already establishes the increase in quality and listening enjoyment playing some of these CD's w/the AK1499E/Q, ... the question remains ... why did, for example, the RR CD, very clearly, have zero change? In other words, how does one CD present very noticeable audible change from these two chip configurations while sliding in another CD presents zero audible changes. (Note, volume level was set medium-high throughout). What are technical reasons for this type of inconsistency between CD's; we know the Chip is OK, and all cables, amps, preamps were the same for both DAC's, as well. Thank you.

It's improbable that anyone can offer technical explanations without more details on your A/B testing methods that confirm significant biases were eliminated. If providing such information isn't feasible or you're unable to prove bias minimization, psychological factors might explain the perceived differences in sound quality.

 

[Mnyb]

Any HDCD or preemphasis CD ? Or failed AB

 

[Mnyb]

Are some of these masters hot ? Have samples at 0 dB which can generate intersample overs ?

Try the same tracks with -3dB attenuation ( rip the CD and use files )

 

[DVDdoug]

(e.g., sound-stage depth, better articulation). Why? Thank you.

NOTHING in the electronics or the digital domain should "accidently" affect that. Of course you can apply EQ or other effects.

CDs are "only" 16-bits/44.1kHz so I wouldn't expect an improvement with a "better" DAC. But "CD quality" is generally better than human hearing (in proper blind listening tests).

If you hear a difference or defect from a DAC, it's usually noise. I don't claim t have golden ears, but personally, I've never heard a defect or difference from a DAC, except I had a noisy soundcard once that made noise when the hard drive was accessed. (I don't blame the soundcard's "DAC" for that.) Distortion and frequency response are usually better than human hearing.

What is a blind ABX test?

Audiophoolery

 

[Chrispy]

Failed A/B. In other words there was no change between the two (DAC's) on this one CD ... the RR recording mentioned above. So, what I am gathering from all of you, there is no answer why this CD is not affected by the AK1499E/Q, that is, it sounded like it has since I bought the SA8005 years ago. I only played three CD's last night, but guessing I will come across more failing the A/B. The A/B test was conducted w/my knowledge which one I was listening to, and it was completed instantly with a click of a button on a remote control commanding a preamp. Thank you.

Or you could say there's no reason the dac would make any difference....

 

[Mnyb]

Caveat , are we dealing with a homebuilt DAC not a known product ? Chipset used is a one factor but the total result is the while DAC ?

As for the result an original analog recording such a sketches of spain is about 11-12 bits SQ anyway and can not challange any DAC ?

 

[Mnyb]

The older recordings may not have any Hf content above 10-15kHz so insensitive to filter settings .

Modern DAC chips has many ( to many ) filters to choose from ..

 

[Chrispy]

The older recordings may not have any Hf content above 10-15kHz so insensitive to filter settings .

Modern DAC chips has many ( to many ) filters to choose from ..

Just how audible are such, tho?

 

[voodooless]

Just how audible are such, tho?

The op is probably 70+, so I would not worry about HF content very much. Unless he’s very lucky, he won’t hear much past 12 kHz.

 

[Mnyb]

Just how audible are such, tho?

I dont know but some of the filters are ”wrong” they do have impact well below 20kHz ( why are AKM and ESS keeping these ) and very leaky.

I think most of the choices are inaudible especially for us older folks those who make a difference are “wrong” AKM should simply stick the setting to the one that follows theory best and keep the other settings hidden for thier lab work IMO.

 

[Chrispy]

I dont know but some of the filters are ”wrong” they do have impact well below 20kHz ( why are AKM and ESS keeping these ) and very leaky.

I think most of the choices are inaudible especially for us older folks those who make a difference are “wrong” AKM should simply stick the setting to the one that follows theory best and keep the other settings hidden for thier lab work IMO.

Such as?

 

[voodooless]

Such as?

All the ones marked may be suspect.

 

[Mnyb]

Not Home Built. The DAC is a well made, we can say, Mid to High-end (about $1000) piece.

But its not a product with documented performance?

 

[LanceLewin]

Very interesting - thank you all for presenting possible culprits. I look forward to researching some of what you have offered.
In any case, in a well rounded 2-channel system, the DAC is only one part of the equation. In this case, it seems, for now,
my current SA8005 seems to still hold significance within the system. Thus, I will turn my attention to improving the sound/music
from my vinyl-playing apparatus. The new DAC will be returned to the Mfg. Thank you, all. Ciao.