XXHighEnd

Ultimate Audio Playback => Chatter and forum related stuff => Topic started by: manisandher on February 17, 2013, 11:33:48 pm



Title: Keith O Johnson RMAF10 - High Resolution from the Masters
Post by: manisandher on February 17, 2013, 11:33:48 pm
I recently came across this video: http://www.youtube.com/watch?v=bBR3kS4e_wk

I know everyone's so busy nowadays running around, and this video is a whole hour long, but I strongly urge you to take a good hard look at it.

He starts off a bit slow, but then gets into his stride. He talks about problems with PCs that no-one really understands, issues with delta-sigma converters and a whole bunch of other stuff that's relevant to us.

I'm sure you, like me, frequent these boards not because you love PCs, but because you love music and want to hear it in its full glory. Watch this video and learn from someone who knows what he's talking about.

(Although I have to admit that I still don't understand the bit about vinyl having "120dB dynamics". I'd love an explanation from someone who does.)

Mani.


Title: Re: Keith O Johnson RMAF10 - High Resolution from the Masters
Post by: PeterSt on February 18, 2013, 11:07:40 am
Quote
(Although I have to admit that I still don't understand the bit about vinyl having "120dB dynamics". I'd love an explanation from someone who does.)

I didn't watch the YouTube, but I tend to put this a bit the other way around :

Why would 120dB be impossible ?

I think it will depend largely on the (very special) pressing, the cartridge used (may not be a commercial one) and for the remainder the SNR.

IOW, and with the SNR as a main theoretical issue, what can hold back (for physics) ?

Peter


Title: Re: Keith O Johnson RMAF10 - High Resolution from the Masters
Post by: christoffe on February 18, 2013, 12:18:39 pm
I recently came across this video: http://www.youtube.com/watch?v=bBR3kS4e_wk


Good informations.
The main conclusion is, it comes down to enhance the hardware and to optimize the power supply together with  earthing.

Joachim


Title: Re: Keith O Johnson RMAF10 - High Resolution from the Masters
Post by: Jud on February 18, 2013, 01:04:24 pm
Thanks for the reminder, Mani.  One of these days I *must* find the time to watch the whole thing.  I've only seen short segments, and they're very good, as you would expect from someone that smart, persistent, and careful, who has been working in this field a long time.

About the -120db, I can't off the top of my head remember exactly how he's explained it, but Keith Johnson has talked about this subject many times before - that is, the wide dynamic range available from vinyl (as well as, somewhat paradoxically, its usual superiority to CD in that respect).  It may have something to do with hearing into the noise.

For my own experience, whatever that is worth (recognizing the plural of anecdote is not data, as they say), it has been quite surprising to me that virtually none of the CD or even hi-res download versions of favorite old LPs have been able to duplicate the special dynamic moments of the originals.  The one I always come back to in this regard is that famous first electric guitar chord slashing in after the strummed acoustic intro on "Pinball Wizard."  With my $400 30-year-old turntable and $125 cartridge playing my 43-year-old LP, either for myself or demo-ing for friends, that moment never fails to amaze.  The CD and especially the DVD-A (the HDTracks download is taken from the same recording as the latter) are disappointingly weak.  Only the SHM-SACD has now finally been able to recapture most of the drama.


Title: Re: Keith O Johnson RMAF10 - High Resolution from the Masters
Post by: CoenP on February 27, 2013, 11:29:06 pm
Thanks for the excellent lecture.

Another remotely related observation about 'what do we really know about our hearing' dropped in my mailbox today:

http://www.innerfidelity.com/content/headphone-cable-measurements-wrap (http://www.innerfidelity.com/content/headphone-cable-measurements-wrap)

The writer tries to deal with the (barely) audible differences between headphonecable and cites a really interesting article about the unexpectedly acute human auditory perception.

I personally really like the part about timing and missing harmonics ;).

Regards, Coen