How much of burn-in/ break-in (in hours) is objective vs. getting used to sound?

[jkeny]

Some will ignore this comment too but any DAC that sounds "screetchy and harsh" when you first plug it in, doesn't belong in any audiophile's room much less a record producer. If an hour of use could have saved it from that horror, you should have done that before sending it to customers.

I knew that my story would attract a comment such as this but I posted it anyway. Mind you I was waiting for the comment about "properly designed" etc.

I will copy my email reply to him:

Yes, I've seldom had a reports of quiet such a harsh sounding initial sound - maybe your system is more revealing than most?
I hope the engineering team came back after a bit of burn-in to hear it's development?
Yes 48 to 100 hours is needed before full burn-in.

 

[jkeny]

Do bolts know if they are holding the tire on your car or being used to keep your car stereo in the dash? You think their use and performance is interchangeable???

What kind of question is that John? Of course caps are used under wildly varying conditions and you can't translate one use to another. An audio DC blocking capacitor would blow its mind to pieces if you put it in the output of a switchmode power supply due to too high of ESR (internal impedance).

In this case, the cap was being used as part of an LP RIAA equalization buffer amplifier. And it was that combination that was measured. No way can you extrapolate to use of capacitors in general. Caps are used in many different roles and their impact on the final performance of device is hugely different.

My comment was exactly to highlight your attempt at trying to make this into a specific phenomena & hence dismiss it (as Self himself did) - "a corner of a corner of a corner" I believe is how you put it.

Your objections were that Self had only measured this distortion in a specific configuration "filtering use" & I was asking you if the capacitors didn't suffer the same distortion when not used in filters?

You also argued that his measurements were not repeated. Same can be said for all of your measurements, yet you put great store in them, declaring products as snakeoil as a result

All you were really short of stating was 'how do we know it is Douglas Self who wrote the article'? 'How do we know the measurements weren't made up'
Amir, the possible variations of deniability are multitudinous, as you have demonstrated.

And again you ignore what the article is about & why I posted it - to show measureable distortion which follows a pattern of burn-in cycling. This is what has been denied by you & others so far in this thread


What you also fail to register is Self's statement that "some real types of capacitors have easily measurable distortion across them when significant voltage across them. For electrolytics this is as low as 80mV....." Burn-in in electrolytic capacitors is a known phenomena. Are you denying this? Are you stating that you are sure burn-in changes in audibility don't exist? You inadvertently go most of the way to admitting this is probable in your comment "Caps are used in many different roles and their impact on the final performance of device is hugely different."

Self didn't test elcaps burn-in distortion - does that mean it doesn't exist?

As Stehno has said you seem to bring little real experience to the discussion but lots of absolute statements

 

[DaveC]

Just an anecdotal story (which some will ignore) from an experienced & well known record producer who bought one of my DACs

Yup, about an hour is where I tend to hear components sounding better. Every single component I've built myself has had a pretty huge burn-in change. Many may never experience this depending on how much testing is done by the mfg'r. The cable I posted measurements of is similar, it changes pretty radically during the first few hours, but also more subtly improves over hundreds of hours. Most wire doesn't have a burn-in this extreme, but it seems all/most components do. I would agree with Amir that this initial burn-in should be done by the mfg'r, burning in my cables has made things much easier for both myself and my customers. Of course going from getting a lot of comments and concerns about burn-in before I got my cable cooker and none after is also evidence...

 

[DaveC]

Audio paranoia... next up on the 11PM news...

You really think everyone is stupid... LOL

Good thing we have much smarter folks who truly understand the way the world works to guide us and save us from ourselves, kinda like a Jesus/Mohammad/Buddha of audio. Acoustic saviors, lol! Or, could it be a narcissistic personality disorder? What would Occam say?

 

[jkeny]

Yup, about an hour is where I tend to hear components sounding better. Every single component I've built myself has had a pretty huge burn-in change. Many may never experience this depending on how much testing is done by the mfg'r. The cable I posted measurements of is similar, it changes pretty radically during the first few hours, but also more subtly improves over hundreds of hours. Most wire doesn't have a burn-in this extreme, but it seems all/most components do. I would agree with Amir that this initial burn-in should be done by the mfg'r, burning in my cables has made things much easier for both myself and my customers. Of course going from getting a lot of comments and concerns about burn-in before I got my cable cooker and none after is also evidence...

Well I guess I haven't had any complaints from customers about the burn-in period - they are made well aware of it beforehand & have a full return policy so they feel no time pressure as a result.
I spend my time dealing with the issues that will improve my devices instead of burning in DAC, converters, etc.

 

[amirm]

I knew that my story would attract a comment such as this but I posted it anyway. Mind you I was waiting for the comment about "properly designed" etc.

Well, let me make you feel better then. There is no way, no how I believe any DAC no matter what the price, when plugged in sounds "screetchy." I am confident that in a blind test your customer would not have been able to identify your DAC let alone be able to determine it was screetchy. These are faulty subjective evaluations which must be dismissed instead of building a house of cards on them by assuming they are correct. A more polite version of this is what you should have told him. That nothing can possibly electrically change in a DAC in 1 to 4 hours to deliver the transformation he thought he heard. That we are unfortunately routinely wrong at these evaluations.

I walk into many high-end rooms at shows and hear such awful performances. And then they play something else and it sounds wonderful.

Don't cling to the improbable John when the most probable reasoning is right in front of you. Did you honestly think your new DAC was that bad, that broken to sound that way? I assume not. You will lose some customers through transparency but it is better to be on the reasonable side and do that, than the other way around.

 

[amirm]

My comment was exactly to highlight your attempt at trying to make this into a specific phenomena & hence dismiss it (as Self himself did) - "a corner of a corner of a corner" I believe is how you put it.

Your objections were that Self had only measured this distortion in a specific configuration "filtering use" & I was asking you if the capacitors didn't suffer the same distortion when not used in filters?

That's right. And I quoted Doug himself saying exactly that. Here it is again:

"Finally, have I stumbled on an effect that explains why some people insist on the need to burn-in so-called high-end hifi for days before it sounds right? Could it be that lurking in that high-end equipment there might be some polyester capacitors that need straightening out? Well, let’s see. The effect only applies to capacitors acting to define time-constants, so it would be restricted to RIAA equalisation networks, tone-controls if you have them, and just possibly sub-sonic filters. It would also only work if the ‘burn-in’ was accomplished by having signals of 9 Vrms or so continuously present in the circuitry. Unless your preamplifier has a very funny gain structure indeed, this is not going to happen, though you could put some extra amplification between the cartridge and the preamplifier input. You would also need to change the vinyl continuously to keep the signal coming in. That is not, as far as I know, what even the most devoted audiophiles do.

Looks like the hypothesis is untenable."

It is clear to me you have not read the reference you put forward. If you had, you would not be questioning me when he is so clear in what a corner and specific case this is. That it applies to only one type of capacitor. That this cap needs to be used in a circuit where it impacts it time constant. And that it would require constant and high level of drive to manifest.

 

[jkeny]

Well, let me make you feel better then. There is no way, no how I believe any DAC no matter what the price, when plugged in sounds "screetchy." I am confident that in a blind test your customer would not have been able to identify your DAC let alone be able to determine it was screetchy. These are faulty subjective evaluations which must be dismissed instead of building a house of cards on them by assuming they are correct. A more polite version of this is what you should have told him. That nothing can possibly electrically change in a DAC in 1 to 4 hours to deliver the transformation he thought he heard. That we are unfortunately routinely wrong at these evaluations.

I walk into many high-end rooms at shows and hear such awful performances. And then they play something else and it sounds wonderful.

Don't cling to the improbable John when the most probable reasoning is right in front of you. Did you honestly think your new DAC was that bad, that broken to sound that way? I assume not. You will lose some customers through transparency but it is better to be on the reasonable side and do that, than the other way around.

I find it's better not to deny reality with absolutist statements - my customers appreciate this. I have been exposed to & heard so many different systems now with my DAC that I know it's characteristics & also know that there are many configurations & many possibilities which can affect audibility. Including common mode noise issues which I'm not oblivious to, unlike many here.

So thanks for your offer but I'm afraid you are badly misguided.

 

[jkeny]

That's right. And I quoted Doug himself saying exactly that. Here it is again:



It is clear to me you have not read the reference you put forward. If you had, you would not be questioning me when he is so clear in what a corner and specific case this is. That it applies to only one type of capacitor. That this cap needs to be used in a circuit where it impacts it time constant. And that it would require constant and high level of drive to manifest.

I'm sorry, Amir, your capacity for avoiding the point of the article & arguing unrelated points, is a wonder to behold & not something I'm willing to waste my time on!

 

[BobShermanEsq]

Well, let me make you feel better then. There is no way, no how I believe any DAC no matter what the price, when plugged in sounds "screetchy." I am confident that in a blind test your customer would not have been able to identify your DAC let alone be able to determine it was screetchy. These are faulty subjective evaluations which must be dismissed instead of building a house of cards on them by assuming they are correct. A more polite version of this is what you should have told him. That nothing can possibly electrically change in a DAC in 1 to 4 hours to deliver the transformation he thought he heard. That we are unfortunately routinely wrong at these evaluations.

I walk into many high-end rooms at shows and hear such awful performances. And then they play something else and it sounds wonderful.

Don't cling to the improbable John when the most probable reasoning is right in front of you. Did you honestly think your new DAC was that bad, that broken to sound that way? I assume not. You will lose some customers through transparency but it is better to be on the reasonable side and do that, than the other way around.

You seem to be so focused on one word, screechy. Why make a big deal out of the one word, what is the problem? What was posted by John makes perfect sense and I believe just like anyone with some common sense would believe is true. When first turned on the DAC did not sound that good and after burn in sounded excellent. Such a simple fact, why all the talk about everyone being delusional and blind testing, please. I've heard this with equipment that I've used, just as most of us have. In an earlier post I mentioned Schiit Audio and what they say regarding their DACs. Do you think they would say this if it was not true, I think Mike Moffat knows a bit more about digital audio than you do, so if you have something you can give us that has some first-hand real world information please go right ahead. Just speculating on what other people can or cannot hear, and different type of testing to prove them wrong really does not cut it.

 

[jkeny]

You seem to be so focused on one word, screechy. Why make a big deal out of the one word, what is the problem? What was posted by John makes perfect sense and I believe just like anyone with some common sense would believe is true. When first turned on the DAC did not sound that good and after burn in sounded excellent. Such a simple fact, why all the talk about everyone being delusional and blind testing, please. I've heard this with equipment that I've used, just as most of us have. In an earlier post I mentioned Schiit Audio and what they say regarding their DACs. Do you think they would say this if it was not true, I think Mike Moffat knows a bit more about digital audio than you do, so if you have something you can give us that has some first-hand real world information please go right ahead. Just speculating on what other people can or cannot hear, and different type of testing to prove them wrong really does not cut it.

Indeed, I thought those absolutist statements denying others genuine experiences were no longer part of WBF as it was what caused a great deal of forum strife in the past?

 

[Steve Williams]

The admin staff is monitoring this thread as it does others

 

[fas42]

I find it's better not to deny reality with absolutist statements - my customers appreciate this. I have been exposed to & heard so many different systems now with my DAC that I know it's characteristics & also know that there are many configurations & many possibilities which can affect audibility. Including common mode noise issues which I'm not oblivious to, unlike many here.

So thanks for your offer but I'm afraid you are badly misguided.

John, you have been pretty game putting out a product which you know will sound so different, depending on the final system, and how the customer approaches listening to it - years ago, I thought a lot about creating a complete system and marketing it, but the fragility of getting acceptable, to me, sound in every reasonable situation stopped it ever happening. So, a big tick from me !!

 

[jkeny]

John, you have been pretty game putting out a product which you know will sound so different, depending on the final system, and how the customer approaches listening to it - years ago, I thought a lot about creating a complete system and marketing it, but the fragility of getting acceptable, to me, sound in every reasonable situation stopped it ever happening. So, a big tick from me !!

Frank, burn in changes in sound is one thing but it doesn't mean my products will sound very different, depending on the final system - by & large it's audible characteristics are the same in each system - some systems will express these characteristics more than others.

As you know, computer audio is not really plug & play - it requires attending to matters to get the best sound. Most of those matters have to do with common mode noise from connecting digital audio devices to a computer.
Different computers & different audio chain configurations & the internals of the audio devices in the chain all have a bearing on how the CM noise will affect the sound. Some Macs, for instance tend to be the worst offenders for leakage currents from their internal SMPS - more so than PCs with SMPSes - a generalisation, I know so don't let this be a

People often aren't aware that they have an issue which is affecting audibility until they address these CM noise issues. I have sorted out many people's such problems because I know the sound that my DACs should provide & if a customer is auditioning my DAC or converter & not reporting the characteristics I know they have some issues which are usually CM issues & can be sorted

So if attended to there will be no great differences in the sound of my DACs in different systems

I gave an example of a visit to Nige with Richard - he had two Soekris DACs with the same tweaks but connected to different systems - one to a tweaked PC & one to an SD card player. The SD card player sounded so much better than the PC - it had a depth of soundstage missing from the PC. When we used a transformer on the output of the Soekris, this brought the PC almost into line with the SD card player & nearly matched the depth of soundstage. We knew the Soekris was being held back by the PC because we had previous experience of what the Soekris sounds like & our experience of what the possible problem was allowed us to focus on the issue & solve it - cm noise.

I take the same approach to my DACs - I can tell when someone is hearing the DAC correctly & when their system is masking something & can attend to it if they are willing.

 

[opus112]

An audio DC blocking capacitor would blow its mind to pieces if you put it in the output of a switchmode power supply due to too high of ESR (internal impedance).

Only if it were a fairly cheap cooking grade electrolytic Amir. And very few respected high end companies use those for DC blocking. They tend to use film or foil caps which have plenty low enough ESR.

Caps are used in many different roles and their impact on the final performance of device is hugely different.

Quite so.

 

[opus112]

I gave an example of a visit to Nige with Richard - he had two Soekris DACs with the same tweaks but connected to different systems - one to a tweaked PC & one to an SD card player. The SD card player sounded so much better than the PC - it had a depth of soundstage missing from the PC. When we used a transformer on the output of the Soekris, this brought the PC almost into line with the SD card player & nearly matched the depth of soundstage. We knew the Soekris was being held back by the PC because we had previous experience of what the Soekris sounds like & our experience of what the possible problem was allowed us to focus on the issue & solve it - cm noise.

This was a most educational experiment as to the damage caused by CM noise. Nige's amp, being chip-amp based, did seem quite susceptible to CM noise. The CM noise could have been sourced by the PC's PSU, equally it could have come from the PC's monitor or a combination of the two. The SD card player had no switching supplies connected to it as I understand.

 

[fas42]

I gave an example of a visit to Nige with Richard - he had two Soekris DACs with the same tweaks but connected to different systems - one to a tweaked PC & one to an SD card player. The SD card player sounded so much better than the PC - it had a depth of soundstage missing from the PC. When we used a transformer on the output of the Soekris, this brought the PC almost into line with the SD card player & nearly matched the depth of soundstage. We knew the Soekris was being held back by the PC because we had previous experience of what the Soekris sounds like & our experience of what the possible problem was allowed us to focus on the issue & solve it - cm noise. I take the same approach to my DACs - I can tell when someone is hearing the DAC correctly & when their system is masking something & can attend to it if they are willing.

We are saying the same thing, John, just in different ways. The point being, that the DAC gets out of the way - therefore, any system "sound" is due to issues elsewhere in the setup. My way is to say that components have no sound, or such should be so - the job is to eliminate all the "injected" spurious characteristics. SD card players can be brilliant - because, they're so simple! It's the debugging where the action is, as you say ...

 

[amirm]

You seem to be so focused on one word, screechy. Why make a big deal out of the one word, what is the problem? What was posted by John makes perfect sense and I believe just like anyone with some common sense would believe is true. When first turned on the DAC did not sound that good and after burn in sounded excellent. Such a simple fact, why all the talk about everyone being delusional and blind testing, please.

Hi Bob. Without knowing it, you are actually arguing my response that you quoted. That there was no way, no how the customer had such a horrible experience when he first turned that DAC on. That is why I put zero, let me repeat, zero weight on that word. With some rare exceptions, today's DAC *devices* are built on DAC *integrated circuits* that are so good that you really can't screw them up that way. And their spec sheet mentions no word whatsoever about the need for burn-in.

I don't know who John hired to design that DAC, or who is manufacturing them. But I am confident even in the worst case, they would not put out a product with such aberrant performance when first turned on. Since the customer said after just one hour performance improved, we know it was not broken which would be the only explanation for such poor performance as he reported and John kindly provided word for word.

You ask for common sense explanation but you can't use such here without understanding how DACs are designed and how "impossible" it is to get them to convert digital samples to analog with such performance when first turned on at customer site. One needs to use engineering common sense and everything there would point to impossibility of the device being so non-performant, however you want to interpret the wording.

I've heard this with equipment that I've used, just as most of us have.

And I trust you that you have as have others. No disagreement on that. The issue is working backward, without technical knowledge and that of psychoacoustics, and coming up with a technical explanation of cause and effect. Study of the former would say what I explained above. Study of the latter would tell you the elasticity of our hearing system. We don't hear the same over time. You can listen to a piece of music 100 times and at episode 101 hear a note you did not. That note was always there. Your brain simply did not focus on it to hear it. This should make common sense to you.

You are pleading with me to understand your universe as you know it. How about doing the reverse a bit and try to understand the universe on the other side? That there are readily explainable causes for differences we hear that are not attributable to causes we attach them to. So to the extent you hope for me to bend your way, I hope you are not so obstinate as to refuse to do the same in reverse.

I will address your last point in the next post. Thanks for chiming in.

 

[amirm]

In an earlier post I mentioned Schiit Audio and what they say regarding their DACs. Do you think they would say this if it was not true, I think Mike Moffat knows a bit more about digital audio than you do, so if you have something you can give us that has some first-hand real world information please go right ahead. Just speculating on what other people can or cannot hear, and different type of testing to prove them wrong really does not cut it.

I don't know Mike Moffat personally so I take your word for it that he knows more than me. What I won't take though the assessment that we should to what he says because I happen to have first hand experience with one of his products. My son bought one of their $400 DACs and unfortunately it lived up to the derogatory version of their company name when it came to both subjective and objective performance. My son reported that he could hear the activities of his computer through the DAC when he was playing games! Let me repeat: despite spending $400 on a stand-alone DAC, the noise from his PC was readily travelling through this DAC.

I put the unit on the bench to measure it. At first one channel cut out. I traced that to the fancy cables they had sold him. The center pin had come apart in the RCA connector due to poor soldering and lack of any kind of strain relief. Replaced that and measured the device and this horrific result showed up:

Anything other than center line is spurious distortion/noise. You can see a spike on the left and right rising up to -50 db. Cassette decks have noise floor below 60 db. Yet we have a digital device producing such awful performance. Mind you even with this kind of problem it did not sound screetchy.

Anyway, their other products may be better and he may be a genius designer. But he sure as heck is not going to get my business or get me to be impressed with anything he might say on this topic. Find some other authority to appeal to as this one will not work on me. I am however ready at any point to test his ability to hear DAC burn-in.

Again, thank you for your comments.

 

[jkeny]

And whose measurements are we to trust - yours or Stereophile's or are you going to state that their measurements haven't been repeated?

Here's their measurements page of the Schiit Bifrost (the model you stated you measured) http://www.stereophile.com/content/...da-processor-measurements#rZ1VBABt4CLrbxhe.97
People can read the graphs & text themselves but the summary starts "Overall, both samples of the Bifrost measured well, especially given the affordable price." Where do we see any sign of the jitter you claim are shown in your plots of the Bifrost?

Your measurements have been called into question many times before & exposed as erroneous by Ifi & now by Stereophile. Do you ever bother to cross correlate or check them before rushing into denigrating a product? Do you ever take pause to examine yourself & your procedures?

Your lack of logic, self-reflection & self-analysis shows in your many inconsistencies. You made the claim that the Self measurements had not been repeated thereby hoping to caste doubt, yet you are quite willing to accept your own once-off measurements when they negatively reflect on a product.

I'm afraid your commonly stated claim of being a champion for the consumer is laid bare by this skewed behaviour, Amir

BTW, I don't hire a DAC designer (why would you make this statement except as an attempt at denigrating my capabilities & experience?) but the rest of your reply to Bob re my DAC is not worth replying to other than to say that you are again severely misguided in all you say.