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Old 8th January 2014, 09:25 PM   #691
impuls is offline impuls  Yugoslavia
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Sorry, lack of time. Akai cd79 with LC on all power supply pins of dacs, conductive polymer for dac, Muse KZ for AD844, PCM63KY, 3x AD844 stacked, sounds better than Meridian G08.2

The sound is much more analogous and more fluid than nervous Meridian. The character of the sound is similar for both cd players. Next step will be with two AD844 stacked and additional i/v resistor and Sen/Cen. I want to keep the detail and naturalness but i want to get a little more PRaT (when the foot dancing in the armchair)
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Old 8th January 2014, 09:47 PM   #692
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Hi Impuls, Sorry to say this about such an expensive unit but Meridian G08.2, bit stream delta sigma dacs "yuk", had one here for appraisal for a couple of weeks, interesting as bat s**t on redbook made me yawn. Nicely made though and boringly smooth.
The Akai CD79 with PCM63P-K should be better on redbook with just a little tweaking, and far better with the 844 i/v and a good output buffer. bet this makes you jump on dynamic sections compared to the Meridian.

Cheers George
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Old 8th January 2014, 11:55 PM   #693
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Quote:
Originally Posted by impuls View Post
I want to keep the detail and naturalness but i want to get a little more PRaT (when the foot dancing in the armchair)
IME stiffer power supplies are a good way to improve rhythm and pace. I just increased the capacitance I have across the PSU pins of my I/V preamp - from 6000uF to 12000uF and noticed more inclination to foot tap Seems low impedance down to as low a frequency as possible is important.
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Old 10th January 2014, 10:01 AM   #694
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Quote:
Originally Posted by abraxalito View Post
DSD as a format is technically broken, that's probably why. This is not a matter of opinion, rather hard math.
I have a few DSD recordings I have downloaded and they are fabulous. To me, what is even more important is the quality of the native recording, whether done in PCM or DSD (also could be called PWM or PDM). If they do the recording right, I can live with either formats.

BUT... the real problem is with delta-sigma low-bit DACs and their own attendant noise shaping. Today, most PCM of various bits are processed in delta-sigma DACs - unless you use older DACs and NOS-DACs.

Delta-Sigma DACs, what ever source material they use, need a particular form of post-DAC filtering - and I know of no manufacturer who does it and only a couple of DIY'ers that do.

Read from this post onward: Oppo`s BDP105 - discussions, upgrading, mods...

And: Oppo`s BDP105 - discussions, upgrading, mods...

Coris tries it: Oppo`s BDP105 - discussions, upgrading, mods...

Cheers, Joe
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Last edited by Joe Rasmussen; 10th January 2014 at 10:05 AM.
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Old 10th January 2014, 12:44 PM   #695
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Originally Posted by Joe Rasmussen View Post
BUT... the real problem is with delta-sigma low-bit DACs and their own attendant noise shaping. Today, most PCM of various bits are processed in delta-sigma DACs - unless you use older DACs and NOS-DACs.
Its true that nowadays, the vast majority of PCM recordings are made through an S-D modulator. I rather suspect this fact goes a long way towards accounting for the rather extreme variability of digital recordings in terms of how much dynamics they portray. However it needn't be this way - various vendors have highly capable SAR ADC chips now which boast impressive specs and are reasonably priced. Thinking in particular of both ADI and LT but they're not the only ones, TI and Maxim also make decent-looking parts.
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Old 10th January 2014, 12:55 PM   #696
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Originally Posted by abraxalito View Post
Its true that nowadays, the vast majority of PCM recordings are made through an S-D modulator.
I would like you to consider those links (and postings around them and subsequent posts) on the Oppo 105 thread where the 'single order dominant pole' used in the post-DAC circuit, is discussed. It is not just theory, now that too many have sampled (heard) the results and 100% agreement that it works, only that the theory and why it works is open to discussion.

In fact I think you have been there on that thread, pardon my memory.

Cheers, Joe
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Old 10th January 2014, 01:08 PM   #697
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Why would you like me to consider them - do please persuade me they're relevant? I have no beef with your findings about fitting a capacitor to an S-D DAC. To me this isn't of interest (from my pov as designer) because I'm for the forseeable future sticking with multibit DACs in my designs.

If anyone comes up with a hypothesis for how it works, I shall certainly be interested in that.
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Old 10th January 2014, 01:28 PM   #698
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Originally Posted by abraxalito View Post

If anyone comes up with a hypothesis for how it works...
A single pole filter cannot ring... think about it.
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Old 10th January 2014, 01:40 PM   #699
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It seems to me you're being particularly cryptic tonight Joe
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Old 10th January 2014, 02:18 PM   #700
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A single pole filter cannot ring... think about it.
Correct - but it is not phase linear.

T
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