Paul's view on Cables, Audio Precision Analyzer, etc.

[mansr]

As a rule of thumb, if you're looking for the truth, you can take whatever Paul McGowan says and invert it.

[mansr]

For jitter, wouldn't better results be obtained by measuring at the clock input to the DAC chip using a (ridiculously expensive) phase noise analyser? These specs for a Rohde & Schwarz instrument should be good enough for most DACs:

 

Such a measurement obviously won't take into account any degradation within the DAC chip, which I don't know how bad it might be. Then again, if it is too bad, all those fancy clocks won't be doing any good.

[mansr]

1 hour ago, Arpiben said:

Except that frequency range is from 1MHz up to 400 MHz...😉 (5125a)

And they seem impossible to buy.

[mansr]

11 minutes ago, Superdad said:

John Miles--developer of the original Timepod (upon which the Symmetricon/Microsemi units are based) and author of the terrific and open-source s/w for it--has gone to work for Jackson Labs. His joining them has resulted in the recent introduction of the PhaseStation: http://www.jackson-labs.com/index.php/products/phasestation_signal_source_analyzer, at a much more reasonable $13,460.

That amount of money for a device relying on proprietary software that may or may not work next year is not what I call reasonable.

[mansr]

2 minutes ago, christopher3393 said:

How did you discern that the software may not work next year? Is this a subjective opinion?

Windows updates occasionally break old software, especially device drivers. If the vendor, for whatever reason, stops supporting the product, it is only a matter of time before it breaks. Happens all the time.

[mansr]

5 minutes ago, christopher3393 said:

So you are suggesting it's a calculated risk that you would personally prefer not to take. Do you know this vendor's track record, or are you, perhaps, overgeneralizing because you just don't like the price?

I know nothing about this particular vendor. I have no reason to doubt their competence, but that's not what this is about. All products are eventually discontinued. Even if the company has every intention of supporting this device for the foreseeable future, they might be acquired by someone with different priorities, or they might go bankrupt. Happens all the time.

[mansr]

22 minutes ago, jabbr said:

John Miles is a very well known and respected guy in the [time-nuts] community.  These guys do this primarily for radio, not audio. He has a track record. http://www.thegleam.com/ke5fx/

 

His product is really quite nice.

I don't doubt that he's a nice guy or that the product is great. It's the reliance on proprietary Windows-only software that bugs me. Sooner or later it will stop being supported, and then you'll have a very expensive paperweight.

[mansr]

12 minutes ago, jabbr said:

You can't even imagine what it takes to get that old HP/Agilent equipment to run ... not just some specific ancient version of Windows but with a clock rate limited CPU ... and lots and lots of duct tape.

A self-contained device should simply keep working until it breaks physically.

[mansr]

7 minutes ago, jabbr said:

These types of phase measurement pieces are not self contained.

And that is the problem.

[mansr]

8 hours ago, opus101 said:

Its a mythological beast. I have asked on at least one other forum whether there is in reality a category of such ('competently designed DAC' is a popular synonym), but precisely zero people have offered a checklist so that any particular DAC can be included in (or excluded from) the mythical category. A category without such a means of inclusion/exclusion only exists in the imagination.

I don't think there are any specific traits that are necessary for or prohibitive of a competent design. The presence of certain design elements are at best indicative one way or the other. Reality is not made up of simple categories defined by checkboxes. That's marketing.

[mansr]

3 minutes ago, The Computer Audiophile said:

Ok, understood. I have some changes for the site, almost ready to announce. People will be able to discuss things without the other side stifling discussion. It will work both ways. 

Oh, great. Echo chambers. Just what we need more of.

[mansr]

23 minutes ago, The Computer Audiophile said:

People feel stifled if others disagree

I don't feel stifled if others disagree. I feel stifled when they tell me to shut up.

[mansr]

2 minutes ago, Iving said:

You seem to be missing the point @mansr

Was I supposed to keep quiet?

[mansr]

40 minutes ago, kumakuma said:

I strong disagree with the section in bold.

 

Using one of your beloved car analogies, some roads (recordings) are like this:

 

 

No futzing around with the car (the rig) is going to provide a satisfactory driving experience here.

[mansr]

9 hours ago, marce said:

And EMC testing!

Fun and cheap!

[mansr]

3 minutes ago, kumakuma said:

What can be optimized on a DAP other than perhaps the cable that connects it to the amp?

The power supply for the charger. Gotta have clean, linear power in that battery. Charging it even once with an SMPS is ruinous. On discharge, some of the noise remains in the battery, forever contaminating the power. Even homoeopathic amounts make a night and day difference to the discerning ear. On a quiet night, I can — and this should be no surprise — sense the disapproving sighs of my future wife rippling back in time from the kitchen in the house we will one day inhabit. I should have known better than to live next door to a heathen with an SMPS. It was years ago, but the noise still lingers. I replaced all my audio equipment, to no avail. The noise must have survived in the static electricity on my clothes. It's a nightmare. I pray to every deity — extant, imaginary, or purely hypothetical — that it not infect my nervous system. As long as that doesn't happen, there is still hope that I may some day be rid of it.

[mansr]

14 minutes ago, lucretius said:

How many variants of DolbyA encoding are there?  And what distinguishes FeralA from other variants of DolbyA encoding?  Thanks.

• Wild-A. The ancestor. Majestic. Very difficult to master. Only a few recordings remain.
• Domestic-A. Fairly docile. Bred to fill a variety of needs. Common on LP vinyl.
• Feral-A. Descended from escaped Domestic-A. Somewhat temperamental, but submissive if treated with patience.
• Hybrid-A. Mostly descended from Feral-A interbred with B, C, and occasionally even dbx. Unpredictable. Difficult to tame.
• Fossil-A. Extinct, known only from ancient Greek pottery fragments. Believed to be a common ancestor of A, B, and C.

[mansr]

2 minutes ago, John Dyson said:

You are prejudging the quality of my equipment and my ability to discern. I take exception to that uninformed prejudice. 

John, just ignore Frank. Everybody does.

[mansr]

Here's a bad recording:

 

So bad, in fact, that the FBI spent over two years investigating it.

[mansr]

49 minutes ago, John Dyson said:

Believe it or not, just tested it on a lark -- it is almost definitely feralA!!! 

That can't be. It was recorded in 1963, two years before the Dolby company was founded.

[mansr]

2 minutes ago, Ralf11 said:

so if the FBI had a feralA decoder...

They might have heard the drummer shout "fuck" (at ~0:50) and declared it obscene.

[mansr]

28 minutes ago, fas42 said:

Well, I was inspired to retrieve the best audio of that Louie Louie version, so that the media player would have a nice chunky WAV to work with ... niiice!!! Drums are great, good acoustic, voice set way back in the background - unconventional mix, but it works!!

It was recorded with a single microphone dangling high above the band. The singer had to look up and scream at the top of his lungs to be heard at all over the drums.