Generational fidelity loss with repeated DAC/ADC loops.

[Blumlein 88]

This is related to my other poll. The question of how much fidelity is lost by the ADC used for recording.

I used a Focusrite Forte for the ADC. In this case I took one of my better measuring DACs, and recorded the same 9 songs. I took the first recording and played it again which was recorded again. Etc. etc. Hopefully this would let you gage the deleterious effects of each pass thru the DAC and the ADC.

I will also make this a poll. Just to keep you honest. No one can argue preference. In this case you either get it right or not.

Each link will download a zip file which will open into a folder that has the song labeled as W, X, Y or Z. The generations are consistent between the songs. So I would like for you to listen and choose which version of the song was the original generation and which is the 4th generation copy. Here are the links to download.

Ana Caram via Chesky.
https://www.dropbox.com/s/sokj5wdljpln61d/Generations Ana Caram I.zip?dl=0

Ana Caram again.
https://www.dropbox.com/s/6x9l92d0b9p93uw/Generations Ana Caram II.zip?dl=0

Fiona Apple.
https://www.dropbox.com/s/4pwzdzb00wkyc3t/Generations Fiona Apple.zip?dl=0

Hyperion Knight on piano via Wilson Audio.
https://www.dropbox.com/s/gq0abrezrwyziwh/Generations Hyperion Knight.zip?dl=0

John Hiatt with some nice guitar and voice sound.
https://www.dropbox.com/s/hn81umrmczjf1bx/Generations John Hiatt.zip?dl=0

John Mayall and Eric Clapton.
https://www.dropbox.com/s/8q47dlq8t8sbbao/Generations John Mayall and Eric Clapton.zip?dl=0

Miles Davis from an MFSL Kind of Blue.
https://www.dropbox.com/s/dwif6jm6subcbdg/Generations Miles Davis.zip?dl=0

Mighty Sam McClain singing blues.
https://www.dropbox.com/s/dvt1wxijlebu61d/Generations Sam McClain.zip?dl=0

Terrel which is early 90's rock.
https://www.dropbox.com/s/tlz4fw19yznh3ce/Generations Terrel.zip?dl=0

With all the discussions about the foibles of DACs and ADCs this should be a slam dunk piece of cake.
Please make your choices via listening only.

 

[Ethan Winer]

I love tests like this because it shows people what they can really hear (or not hear). I did this years ago, twice. A good converter is transparent after at least a few generations. You can hear multiple generations with a $25 SoundBlaster card, and then test yourself with a higher quality modern USB converter here:

Converter Loop-Back Tests

 

[fas42]

Okay, grabbed 2 sets this time, and did a first run through of the Mayall lot - now have a first ranking, will give it a break and listen again; try the other set, etc.

 

[fas42]

And, have voted. Used the Fiona Apple set to also rank, and it seemed to confirm what the Mayall combo gave me. What I was hearing seemed to be generational losses, it stepped down each time - a slightly deader, flatter quality with each pass, a little more of the sparkle and liveliness, the sense of ambience, was subtracted between each of the versions.

 

[Blumlein 88]

And, have voted. Used the Fiona Apple set to also rank, and it seemed to confirm what the Mayall combo gave me. What I was hearing seemed to be generational losses, it stepped down each time - a slightly deader, flatter quality with each pass, a little more of the sparkle and liveliness, the sense of ambience, was subtracted between each of the versions.

Alright. We have our first actual voter. I will of course reveal the actual generation of each file in time. Hopefully you have started the stampede.

I have a question for you. In your opinion, is the loss for just one generation enough to obscure differences in DACs as done in my other poll? Or do you think while ambience and sparkle are reduced the difference is small enough two DACs with different qualities would come thru differently in the single recording of them?

 

[fas42]

Need to regroup to do the DAC face off, and will let you know! But my gut instinct, and from the quick listen earlier, is that the difference will be small enough that two DACs with different characteristics will still be distinguishable.

 

[Blumlein 88]

Need to regroup to do the DAC face off, and will let you know! But my gut instinct, and from the quick listen earlier, is that the difference will be small enough that two DACs with different characteristics will still be distinguishable.

Okay, sounds good, and was my opinion as well. Wanted an outside opinion on it and thank you for it.

 

[amirm]

I still plan to take the test but my ears are so plugged from allergies/working in the garden. If I remember, I will take a shot tomorrow morning before I go out.

 

[Blumlein 88]

I'm curious why there has been no participation in this poll, and only a single vote in the companion thread about digital generations. Anyone care to provide a clue about it from their perspective?

 

[RayDunzl]

We can't (legitimately) vote till we do the work.

Explanatory Keyword Hint: It starts with 'w'.

 

[Blumlein 88]

We can't (legitimately) vote till we do the work.

Explanatory Keyword Hint: It starts with 'w'.

Okay, you mentioned the W word first. So how could I have made the poll different so it wouldn't be so much WORK? A series of two piece shootouts maybe? A or B pick your choices and argue it out. Winner goes to round two.

I posted this on the other forum so might as well here. In the other thread, I named the DACs used though not which was which. One of them is a sound card in a 6 year old laptop. Another is a smartphone headphone jack output. I would look optimistically upon a world where it takes( W )ork to find the smart phone and laptop of the bunch. All other than the most hairshirted among us will eventually be streaming our music from the cloud over smartphone anyway. If that gives up little or no fidelity then good.

So need a gauntlet be thrown. Find the smartphone or turn in your audiophile credentials?

 

[Phelonious Ponk]

Well my experience was not avoiding the work. I listened. I couldn't differentiate anything worth ranking between them. I'll gladly turn in my audiophile credentials...oh, wait a minute...i don't have any.

Tim

 

[Blumlein 88]

The poll will soon close here are the identities of each file.

W was the 3rd generation copy.
X was 1st generation copy.
Y was the 2nd generation copy.
Z was the original copy.

 

[FrantzM]

I plan to take the test and vote when I am in the USA.. for now it takes forever to download here in Haiti.

I may fare a bit better than the last time I took a similar test, where my results were sobering I must say.. Harman How to Listen software may have been helpful .. We'll see if I hear

Must say this is the kind of test audiophile are riled with, since the often poor results from the untrained listeners tend to strongly suggest that perhaps (I'm being nice) they (we) don't hear as well as they (we) think

 

[amirm]

I am afraid Harman training software is of no help Frantz.

 

[Blumlein 88]

Well in my other poll comparing DACs for preference John Swenson (Regen designer) chose the smartphone as his preferred DAC (this on another forum). He is now trying to determine why it was the best sounding of the files available to listen to in the test. He confirmed even knowing the identities of the DACs in the test the phone still is the best sounding to him. There are many aspects to this which are either humorous or interesting (actually both).

I am reminded of Sam Tellig back when he created a buzz for the little Radio Shack portable player as somehow having superior sound to many DACs. If only I wrote for a magazine and could convince people there was something super special about the Nexus 6P phone sound.
http://www.stereophile.com/content/...le-cd-player-tellig-again#wG9iYKoFc8wJfWQA.97

Then all the big names could weigh in on the merits and people could start making special accessories to use it like happened to the little RS CD3400 portable player. (yes, I remember because I purchased one too, caught up in the hype. It still worked up until middle of 2014). I think the real message is somewhat less than stellar specs causes less harm to sound quality than people imagine it does. And that people imagine plenty.

 

[fas42]

Regarding John Swenson's choice of the smartphone, there might be something going on - turns out that B, the Nexus 6P phone, was my number two pick. I would be interested in what he's saying about it; have you got a link for the conversation, Dennis?

 

[Blumlein 88]

Regarding John Swenson's choice of the smartphone, there might be something going on - turns out that B, the Nexus 6P phone, was my number two pick. I would be interested in what he's saying about it; have you got a link for the conversation, Dennis?

http://www.computeraudiophile.com/f...er-do-you-prefer-28370/index2.html#post546861

 

[fas42]

Thanks. I'll have a look at the files myself, see if I can pick something in them that might shed some light ...

 

[amirm]

Well in my other poll comparing DACs for preference John Swenson (Regen designer) chose the smartphone as his preferred DAC (this on another forum). He is now trying to determine why it was the best sounding of the files available to listen to in the test. He confirmed even knowing the identities of the DACs in the test the phone still is the best sounding to him. There are many aspects to this which are either humorous or interesting (actually both).

Such tests results should be humbling and make one revisit their assumptions about audio and their listening ability. Instead he responds thusly:

"One hypothesis is that with the others high frequency components were exciting resonances in the ADCs digital filter, since the phone doesn't have anything above 15K it may not be exciting said resonances. "

Resonances in the ADC (capture device)? Really?