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MEASUREMENTS: Does "Burn-In" / "Break-In" Happen for Audio DACs?

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Jazz at Lincoln Center Orchestra with Wynton Marsalis did a great job last Saturday night at the Chan Center here in Vancouver. A friend once told me "Jazz should be seen as much as heard!" I think he's right. Always great to watch artistry in the making and correlate the sounds heard with how it was done. It's also a good opportunity to check out the acoustics in a moderate sized venue with minimal amplification of a 15-piece jazz band. Puts into perspective the dynamics and detail of what one hears in the home system.

Some writers seem to idealize live performances, but IMO, more often than not, what I hear on the home system is clearly better - cleaner, more defined, often much more enjoyable assuming the recording was a good one. The best performance and best seat of the house every night! Of course a studio record could never (and is not supposed to) capture the live ambiance or variation that a live performance can provide. That too is often a good thing as I reminisce on some concerts I've been to sitting beside rather annoying concert-goers. :-)

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I realized something the other night after measuring the Belkin PureAV PF60. I have been measuring my TEAC UD-501 DAC numerous times throughout its lifetime with me. I bought it back in early May 2013 and it has been in use for measurements, headphone listening in the evenings, and as part of my media room since then. I've run all manners of signals through it from standard PCM to high-resolution PCM to DSD64/128. It has been on for days playing "background" tunes as well as much more attentive "serious" listening through numerous albums of genres from jazz, to pop, to blues, to hard rock, to classical...

As of this writing in early March, I've had this DAC for 10+ months. I'll very conservatively estimate that I've put on >300 hours of actual audio through it (not just time turned on). I made sure when I first bought it that I would measure it within the first couple hours of use so that one day (now), I can go back and do a comparison to see if any kind of significant "break-in" can be demonstrated.

Note that the test set-up isn't exactly the same... Components are different like the playback computer, the RCA cable, and I'm in a different house as well. But the setup is comparable:

Win 8 PC --> shielded USB --> TEAC UD-501 --> shielded RCA --> E-MU 0404USB --> Shielded USB --> Win7/8 measurement PC

Results:

So, without further ado, here it is at 3 time points - within 2 hours of use, around 200 hours last year when I moved home, and just about 2 weeks ago with about 300 hours of use...
Summary

Frequency Response
Noise Level
THD
IMD

I figure there's no point measuring at lower resolution than 24/96 for something like this. You will note that the stereo crosstalk has a 4dB spread from highest to lowest (remember, we're talking down at -90dB here). The reason is simple. These are different RCA cables. At "<2 hours" and "~200 hours", I was using a 3' length of RCA cable whereas the ">300 hours" measurement was done with a 6' cable due to the inconvenience of a short cable in the current set-up. As I showed in the RCA analogue interconnect test, length of cable makes a significant difference with stereo crosstalk measurements (shorter is better) for the standard zip-cord type I'm using. This could also be the reason for the slightly lower noise floor especially notable on the THD and IMD graphs above (again, remember we're looking at the -120dB level here!). Otherwise, I see no evidence here of a significant change that would be audible.

Conclusion:

These measurements suggest that there really is no such thing as audible "break-in" for purely electronic devices like DACs within a reasonable period of time. People hearing the "effect" on a regular basis are more likely to be changing their psychological expectations over time than the device actually changing sonic character. I guess change could be happening within the first 2 hours but one almost never hear people claim this; for the most part, people recommend something like 100+ hours. Logically, if anything, electronic devices deteriorate in time as components (like capacitors) get old and connectors oxidize.

Sonic change for mechanical devices like speakers would make much more sense... InnerFidelity had an article about change in the sound of the AKG Q701 headphones over time (65 hours). The measured differences in those graphs are much more than what I'm demonstrating here.

In summary... I wouldn't be worried about "burn-in" with purely electronic devices. If you like the sound at the start, great. If not, maybe give it some time for your ears/brain to adjust and see if you like it then. Sure, keep the device on, blast some hard rock or play a burn-in CD if you feel this helps.

If there's no difference with complex electronic devices like the DAC, it'd be quite unreasonable to expect to hear a difference with totally passive "components" (eg. wire/cable burn-in). I find it suspicious that some companies like this one would claim cables needing 400-500 hours (17+ days straight!) to break-in! The more cynical side of me wonders if there is a benefit for companies to do this because it gives them a "grace period" to tell customers to wait. Furthermore the message itself promotes expectation bias towards improvement in time... "No worries! Give it some time to really sound it's best, Mr. Audiophile!"

Subjectively, I cannot say I've ever thought I could hear burn-in. The TEAC sounded good to me from the start and I'd be foolish to claim with certainty any difference at this point almost a year down the road unless of course there were some kind of night-and-day change (which there obviously hasn't been).

An observation - why is it that "burn-in" essentially always results in a reportedly better / smoother / less harsh sound? How does the component "know" that it should go in the right direction? It's not like the electronic component is functioning like the cells of the body where there's a homeostatic mechanism directing the 'healing' towards optimal functioning... Unless of course, we are dealing with a biological mechanism - the ears & brain. ;-)

Perhaps the standard measurements I present here are unable to capture whatever change there's supposed to be. As usual, I propose to those who are certain that burn-in happens to present any links to information or data to support this belief.

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Listening tonight:
Sonny Rollins Way Out West - just got reacquainted with this old 1957 jazz recording. A fantastic vintage recording from the golden age of analogue done with the tube Ampex 350 tape recorder. This was chosen as the first CD release by Mobile Fidelity back in the mid-1980's (I think 1984). There have been many reissues of this over the years and I think the highest resolution one would be the Analogue Productions SACD from 2002.

Enjoy the music everyone...


Recalled Article on Vinyl Rips and High DR...

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Hey guys, I "recalled" an article I posted this AM on why DR increases with vinyl rips based on RIAA EQ processing.

The reason being I think small changes like +2-4dB of DR in compressed recordings using the RIAA EQ are very much based on the resolution of the emphasis and de-emphasis filters. JR_Audio made a comment on this and I had a look at the accuracy of the RIAA curves I made. Indeed, mathematically essentially perfect curves <+/-0.1dB add very little DR extension, maybe only 1dB whereas "looser" accuracy like +/-0.5dB through the audio band could give +2dB with the DR Meter with some idiosyncrasies depending on the song and which frequencies the RIAA inaccuracies lie.

The problem is that these are simulations done on a computer with accuracy of 32-bits. As I said in the original article:
In real life, things are more complicated. Even without a significantly better source master, for the final vinyl mix, small changes can be done to the signal such as mixing all the bass frequencies up to 100Hz into mono or taming of the high notes along with the RIAA curve. The results might be more pleasing or euphonic (see this article on mixing for vinyl and how much work potentially needs to be done). On playback, other physical factors are also involved such as the tracking force of the cartridge/tonearm or idiosyncrasies of the cartridge and accuracy of the phono pre-amp. Also, post-processing such as noise/click/pop reduction would add another variable for the results from "needle drops". If you look at a number of different vinyl rips, it's quite common to see slight DR variation depending on the equipment and technique used (typically another DR +/-1dB is not uncommon).

Indeed, I noticed this afternoon playing with Audition just how easy it was to artificially inflate DR values! For example, mixing all low frequencies <100Hz as mono. I played around with this using Lorde's Royals song using a lowpass filter to isolate those low frequencies and then mix them back into the highpassed upper portions as mono... Even though the sound wasn't significantly different when volume matched, it was not difficult at all to get a DR8 original 24/48 HDTracks version up to DR13. As I noted in the original article, I believe this is just the result of removing peak limits and clipped portions, allowing the calculations to extend these portions with the DSP operations.

Given the effect I saw, ultimately I think there's no conclusion one can draw between what's measured on a vinyl rip and knowledge/proof of whether truly new masters are being used unless specifically told about it!

I guess after trying this for awhile, I realized just how sensitive the DR Meter can be. Ultimately it is useful as a tool to explore the average dynamic range of albums and especially pick out very poor masters with strong peak limiting. It's also useful to determine if 2 pressings are exactly the same.

Anyhow... I might review this later if anything clears up for me in the days ahead; just really hard to post something unless good conclusions can be reached.

I'll leave you with the last bit of the post however...

Parting example:
One example of a vinyl remaster that's truly the "definitive edition" is Stadium Arcadium by the Red Hot Chili Peppers. As usual for Vlado Meller the CD's mastering engineer, the dynamic range compressor was stuck at "11" resulting in a sick album with an average DR5. The vinyl release had proper mastering treatment by Steve Hoffman resulting in a DR12 average. That's the kind of difference one wants to see between CD and vinyl to be sure of truly better vinyl source material.

Have a good weekend everyone. Now go enjoy the music and the weekend... Careful about the Pono droppings this week. :-)

MUSINGS: "The CD can be said to be an analog disc, just like the LP" (UHF Magazine, 2014)

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(On occasion, I will refer to copyright works under the principle of "fair use" for the purpose of commentary. This is one of those posts.) I don't get a chance to hang out at the local large bookstore chain (Chapters) very often. When I do, I will wander over to the magazine rack and see what's on offer for the month. Here in Canada, there is one (and I think the only) magazine catered to

MEASUREMENTS: Audioengine D3 USB DAC / Headphone Amp.

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In the last couple of years, we have seen a proliferation of small sized USB DACs. Devices small enough for laptop-sized portability aimed at the headphone user who wants a bit more power to drive better 'cans' and provide improved sonics than what's available through the laptop's phono jack. I guess it must have begun with the AudioQuest Dragonfly back in 2012. Currently in the 2nd

MEASUREMENTS: Another Look - Audioengine D3 clipping at 100% volume.

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The ability to interact with you guys over the last year or so running this blog has been vastly educational for me! Whether data gathering with the MP3 test last year or comments and suggestions with each post... In general I do try to keep up with comments if I can but after 80+ posts now, I apologize if there are some comments I've missed along the way. The post today is thanks to the keen

MUSINGS: On Experts, Experience, and Opinions...

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So last night, instead of going to bed early as I was supposed to, I decided to have a look at this interview of Allen Sides from Ocean Way Recording on TWiT.TV. As usual, Scott Wilkinson does a fantastic job with the interview and takes questions from the audience. Obviously, Mr. Sides is a man of many years of experience and can speak authoritatively on MANY topics related to audio

MEASUREMENTS: Nexus 7 to Audioengine D3 (A "Kinda Portable" Audiophile Playback)

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Okay, for fun, I thought I'd grab a few measurements of something... Somewhat... "Portable" :-) What you have here is my Nexus 7 tablet connected to an "on the go" cable (5" male microUSB to female standard USB, off eBay - pack of 3 for $10) --> Audioengine D3 DAC/amp --> Sennheiser HD800. Unfortunately, The D3 would not power up consistently when plugged into the Nexus 5 smartphone since

ANALYSIS: A Comparison of DSD Encoders & Decoders (KORG AudioGate, JRiver MC, Weiss Saracon)

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Hello guys & gals, I've seen the question asked of comparing various DSD conversion programs on message boards over the years but have never seen someone try to "compare and contrast" with objective analysis. Let's at least give it a try here. I don't promise unequivocal answers, but hopefully a decent stab at it :-). Remember that any conversion between DSD to PCM is a "lossy" process.

INTERNET TEST: 24-bit vs. 16-bit Audio - Can you hear the difference?

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24-bits vs. 16-bits Audio - A Visual Analogy? Those that have been reading this blog for awhile will recall that these pages started with an MP3 vs. Lossless test that was posted here back in 2012. That was kinda fun :-). As you know, the "High-Resolution Audio" movement is on. A major cornerstone of this is the belief that in the PCM world, 24-bit audio resolution imparts clear audible

MUSINGS: A few words about Pono... And what is "the finest digital copy"?

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Remember everyone, we're not done with the 24-bit vs. 16-bit blind test yet! We're about 1/2 way through before I close off submissions to the survey site. Again, I thank everyone who has tried it thus far and all the awesome responses with detailed descriptions of the gear used and demographic information... Many audiophiles from around the globe have already voiced their "vote" and it's

MUSINGS: It's Vinyl Time!

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Hey there everyone... The 24-bit vs. 16-bit audio survey has now surpassed the 100 responses "milestone" which I unofficially set as the minimum I wanted to achieve for this test. Thanks to all who have already submitted to the test results and please keep them coming - the more results the better the statistical power... You have until June 20th. Still looking for some Russian input to fill out

REMINDER: 1 Week Left (24-bit vs. 16-bit blind test)

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¡Hola amigos! Greetings from here: Swimming with the turtles and stingrays off the coast of the Mayan Riviera... Thought I'd just put up a little reminder that I'll be closing the blind test on June 20th - approximately 1 week from now. At this point, we're up to 120 responses on the survey (muchas gracias). Although there are always limits to test methodology, and I certainly do not pretend

24-bit vs. 16-bit Blind Listening Test Closed...

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The day has arrived... The survey for the blind test ended today! Thank you for everyone with the patience in taking the time to listen to the 3 samples and submitting your results. A few people admitted to only listening "a few times" but it certainly looks like the majority took the time to seriously listen and I certainly appreciate the detailed responses provided. In total, I received

24-Bit vs. 16-Bit Audio Test - Part I: PROCEDURE

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Disclosure: Just in case anyone is wondering, I want to make it clear that I have no affiliation with any audio company. I do not derive any financial benefit of significance from conducting this survey (a few dollars from the ad revenue I suppose). I enjoy the audio hobby and wanted to do some "reality testing". Over the course of 2 months (April 19 to June 20, 2014), an invitation was extended

24-Bit vs. 16-Bit Audio Test - Part II: RESULTS & CONCLUSIONS

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See Part I: PROCEDURE for details around the test samples used and how this study was conducted. In this installment, let's have a look at the results from the 24-bit vs. 16-bit listening test among respondents. First I need to remind everyone that the test procedure was not easy. As demonstrated in Part I, the sonic difference between the original 24-bit track and the 16-bit dithered version

24-Bit vs. 16-Bit Audio Test - Part IIa: The 20 Correct Respondents...

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As suggested by one of the comments in Part II, I have put together a summary of the respondents who got the 3 sample audio tracks correct (answered B-A-A). Let us see if there are any demographic variables that stand out. Remember, out of 140 respondents, 20 were able to identify all 3 24-bit samples. This is of course not significant (p 0.30) - by chance alone, one would expect approximately 1/

24-Bit vs. 16-Bit Audio Test - Part III: SUBJECTIVE COMMENTS & FINAL THOUGHTS

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Part I: PROCEDURE Part II: RESULTS & CONCLUSIONS Part IIa: The 20 Correct Respondents Welcome to Part III; the last in my reporting of the 24-bit vs. 16-bit blind test. In this segment, I want to spend time looking at the subjective differences as reported by respondents to the survey. I also want to spend a few moments offering a few personal observations and thoughts at the end. I.

HOWTO: Spotify (Free) Streaming To Squeezeboxes

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It's been a great weekend! Managed to enjoy BBQ with some family visiting overseas for summer, enjoyed the World Cup finals (congrats Germany), finally put up the dining room pendant light (waiting months for the thing to come in stock!), finished some work-related financial paperwork, and finalized some scheduling for a trip to China later this year. Not bad for a weekend. Even better for

MUSINGS: The Distortion of Truth... More obfuscation.

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Guys, check out this video from Harman: Check out the segments from 11:30. LOL. Somebody has to go back to school and learn the difference between data compression (ie. MP3) and volume compression (ie. crappy engineer) as demonstrated by those waveforms. On the one hand they say they want to sell "better" sounding recordings but they're obviously going after the scapegoat (MP3) instead of the

MUSINGS: Vinyl Update - Technics SL-1200 M3D

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This week, I thought I'd put up an update on the analogue/vinyl changes I've made in the last few months since the "Vinyl Time" post back in May. The Sony PS-T15 was pretty good. It sounds reasonably quiet but certainly not of "heavy build" quality weighing in at 5kg and things like the fluidity of the tone arm and resistance to vibration left a bit to be desired. I started buying a few more LPs
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