New Linear Power supply upgrade for DMP A-6

No, it's his opinion and that it is a lie is your opinion.

 

No the ‘opinion’ that the A-6 will not be improved by a separate power supply is substantiated by its measurements.
Keith

 

Find the nearest wall and bang your head against it!!!

 

It goes back a lot further in this thread though, try page 4/5. I tried to interest Keith in actually listening in person to a standard A6 vs a modified A6 with the LPS-A6 power supply and he refused to engage with that offer. This was literally what the thread was about in the first place. He literally does not rate what anyone says they hear. Now I think when someone reports on a forum what they hear, that is a vote, an opinion on the matter under debate and should be respected. He refuses to give any weight to that opinion and insists on blind tests with strict volume controls, otherwise he ignores anything you say. I think anyone who is interested in how an audio component performs in reality looks at all available data be it subjective or objective. We can all assign our own weight to individual opinions. Keith seems to assign zero to all views other than his own. Fine but this will inevitably be seen as somewhat insulting by others. I say this as a retired scientist with considerable understanding of the measurement process, though not in the audio domain. Be more humble, less assertive and yes arrogant.




Of course he will say that unless we have annunsighr

 

The last part sentence I thought I had edited out, please ignore.

 

If that would knock some sense into it…
Keith

 

To me there is very little room for misinterpretation here

or here

 

Warning: This is going to be a long post, so if the subject doesn't interest you or you can't read beyond the first 5 lines please feel free to give it a big miss and move onto the next post. Product identifiers have been purposefully redacted to offset the possibility of litigation by the company who markets the products I'm about to discuss. This reply may have to be split up over two or more posts as the allowable 1000 character count might be exceeded.

Okay, just a recap of what I wrote: "No, 50 years of critical listening does not count for nothing. I'd estimate we've clocked up about the same mileage and even though my hearing isn't as acute as it once was it isn't shot either." See how the phrasing of the sentences can lead to a potential misinterpretation.

It would seem from my words that I was implying @Fergus only listens critically which wasn't what I intended to convey, so apologies to you if it read that way. Perhaps I should in retrospect have rephrased my words to read "I've been listening to music for the past 50 years, (some of it critically for professional evaluation reasons), so I don't think it counts for nothing." Then maybe going on to qualify the statement with a bit about my former professional life to add perspective.

I'm both a critical listener and a casual (now please don't take that offensively) listener. I listen mostly for pleasure but part of my former professional life (I'm now formally retired from the industry) involved designing, developing, modifying and repairing audio equipment so critical listening was part of the job description and still is as I've continued in a somewhat reduced capacity to design, develop, modify and repair audio (and other electronics) since my retirement. I still deliver talks to interested groups and run workshops for avid DIYers who want to learn more about the hobby and improve amongst other things their soldering skills.

So as much as subjective evaluation of design, development, a post repair or modification is extremely useful, measurement test results are most certainly a quick way to pin-point problems and issues when things don't quite go as expected or to prove that what was done actually resulted in a real improvement not just an imaginary one. Of course 99.9% of audio enthusiasts and music lovers don't have access to elaborate test equipment nor necessarily the knowhow of how to operate it nor interpret the results, so most just rely on what they hear as their principal evaluation tool. Nothing wrong with that but listening alone has its limitations and is highly dependent on the one and only tool you have and that's your ears. If you are only listening for you own personal enjoyment which is probably the name of the game of the vast majority of audiophiles, then if it sounds great to you that's all that matters. It's however a different story when you are repairing or modifying someone else's equipment. Although I do use my own hearing as a tool to give me audible clues as to what might be wrong with a piece of equipment that I'm repairing it's not the only tool I use. My hearing is far from perfect. It certainly doesn't have the upper frequency sensitivity it once had. I do rely on measurements to ensure everything is as it should be. It simply takes the guess work out of the equation. So, do measurements matter? In my professional capacity and IMHO they do. It takes personal bias and subjective judgement out of the equation. You can easily prove measurement results and the methodologies employed to attain them, where subjective opinion is just that - subjective and often coloured by personal bias, whether that be by expectation, brand association, reputation, taste or simply because you have invested the money.

TBC

 

Part 2

Please don't get me wrong. If it sounds significantly better or different there's probably a reason behind it and there's also a good possibility that those differences can be measured. What I find personally annoying is when some reviewers claim night and day differences when they replaced the stock equipment fuse with a so called "audiophile" one. Here's a classic example of audiophool marketing BS -

[Copied directly from the website of a well known manufacturer or marketer of audio accessories. All I've done is number the questions so I can hopefully as clearly and as unambiguously explain what's fundamentally wrong with each and every one of their claims.]

Frequently asked questions.
Q1: Are fuses directional?

A1: Yes, fuses are directional. Electricity should flow from the left to the right when you view the fuse. If you do not know the direction of flow you should listen to the fuse inserted in both directions. One direction will sound more detailed. This is the correct way.

Q2: Do fuses have a burn in period?

A2: Yes, most products have a settling in period. The first 200-300 hours of use are the most crucial.

Q3: Where should I use my Master fuse(s)?

A3: To get the most out of our Master Fuses, we suggest starting with one or two fuses in most systems, and possibly more for highly resolving systems. There is no "wrong" component to start with; however, we typically recommend starting "upstream," at the beginning of your signal source (Music Streamer, CD Player, Turntable, Reel to Reel, etc.). From there, we suggest moving on to your digital-to-analog converter or phonostage (if you use one), followed by your preamplifier and then your power amplifier. If you have multiple sources, upgrading the fuse in your preamplifier first can improve the performance of all of your sources."

[Not part of their Q&A but a claim published on the same webpage]
Claim 1: "We’re so sure you’ll love what **** and **** Fuses do for your system, we sell them with a no questions asked, 30-day money back guarantee so you can audition **** and **** Fuses in your system risk-free. Then if you’re not 100% satisfied with your system’s performance on **** and **** fuses, return the fuses to your dealer in like new condition for a full refund."

So let's take a look at the marketer's answer to the Q1 and then scrutinise their claims.

Firstly fuses are not directional. If they were they wouldn't work if installed the wrong way round. Alternating current is changing its direction 50 or 60 times per second depending on the frequency of your mains electricity supply and as much as 400 times per second on reticulated a.c. power feeds on most commercial aircraft. So can someone please explain how the fuse knows if it is installed backwards and why it wouldn't function correctly if installed "backwards"?. They state that "Electricity should flow from the left to the right when you view the fuse." What if your fuse holder is wired in reverse intentionally by the manufacturer of the equipment? What if it's a fuse in the d.c. part of the equipment? How's the layperson to know which way the current is flowing or how the fuse holder is wired? IMHO this makes the claims ludicrous especially when they want to hedge their claims by having an each-way bet by suggesting the customer reverses the fuse to determine the correct orientation.

Furthermore they go onto say that in answer to Q2 they claim that "Yes, most products have a settling in period. The first 200-300 hours of use are the most crucial." which to my interpretation implies you might have to have these fuses installed for as much as 300 hours of listening time to realise their full potential. Now let's read this in conjunction with a statement they make on the same webpage. "We’re so sure you’ll love what **** and **** Fuses do for your system, we sell them with a no questions asked, 30-day money back guarantee so you can audition **** and **** Fuses in your system risk-free." That's a pretty bold claim and one would imagine you could easily not be risking your investment if in the event the product turns out not to deliver the performance improvements it promises to your complete satisfaction. But there's often a devil in the detail. Let me elaborate. How much listing do you have to do inside the 30 day money back satisfaction guarantee period to be covered? Well folks to achieve the 300 hour criteria works out to be 12.5 days of continuous listening 24 hours per day or 37.5 days of you can only put in 8 hours per day, every day. Now I seriously doubt that even the most dedicated audiophile is going to aim for the 12.5 days straight and seriously guys who normally listens to their system for 8 hours per day every day? So even if you're a pretty dedicated listener and actually listen to your system for 8 hours each day the 30 day money back guarantee is going to expire 7.5 days before you reach the 300 hour deadline. So I suppose if you're not completely satisfied with the product and the "... no questions asked , ..." part is actually honoured then maybe they won't ask you to prove you actually put in the full 300 hours.

Let's look their answer to Q3 of their FAQ. They suggest starting with one or two fuses and then expanding the fusing of your entire system starting with source components and finally through to the power amplifier. Now I think it's generally accepted that a chain is only a strong as its weakest link, so if the stock standard manufacturer fitted fuses installed in your electronics are as inferior as this company suggests compared to their "superior" fuses then IMHO to realise the full potential of your entire system you'd have to replace all the fuses. This wouldn't be an inexpensive exercise considering their "better" fuses cost almost USD600 each. This in a typical solid state stereo power amplifier alone could involve replacing at least 4 fuses in the d.c. distribution side and one on the a.c. mains supply side and we haven't even equipped the other components in a typical system bearing in mind their recommendations above in Answer 3 of their FAQ. I also wonder how many laypersons with very limited technical knowledge would know how to identify the rating of a fuse, the type of fuse (let's just break it down to the most common types of fast acting, slow-blow and HRC for the purpose of the discussion), let alone knowing the difference between a 3AG and M205 physical sizes or even be comfortable opening up their equipment to replace internally installed fuses on the various printed circuit boards they might be installed on.

I did reach out to the company asking for a few key technical specifications on their fuses like hold current, rupturing current versus time, tolerance, UL certification etc. and I actually got a reply. They said they couldn't give details because the specifications I was enquiring about were commercial in confidence and a trade secret. This is quite a different response to what one is likely to get from reputable fuse manufacturers like Littelfuse who openly publish full specifications for all their fuses on their website for any Tom, Dick or Harry to read.

So for me it begs the question. Are these esoteric fuses any sonically better than a fuse from a reputable manufacturer like Littelfuse? I can partially answer that question as I've seen them in customer's equipment and I make a point of conducting a listening test on every piece of audio gear that gets repaired, restored or modified in my workshop before it gets sent back to the customer. I've swapped out these very expensive fuses for an inexpensive Littelfuse and heard and measured absolutely no difference in performance. BTW if you are asking why I would even bother doing this, the answer is simple. If during the fault diagnosis and electrical testing phases a fuse does blow, I'd rather blow a 50c Littelfuse rather than have to replace a $600 fuse out of my own pocket.

In the audiophile world beauty is definitely in the eyes or should that be the ears of the beholder. If someone wants to spend $600 on a fuse because they truly believe it elevates their audio system to a much higher level then so be it. Who am I to judge or dictate what people spend their money on or do, if they perceive it improves their audio system's performance? However I know where I'd rather be spending my money but that's another story for a rainy day.

 

Yes, those fuses are interesting. Powercabels are too, esspecially if you think they are connected to a wall socket which is connected to some random wire.
I cannot imaging that they make a difference, but I also do not have a system which has been optimized to the last screw - and my ears arent either.

I have found that sometimes, due to my experience, a break-in period can improve the sound quality of loudspeakers and headphones.
I used to own a digital amplifier, the Ayima A7 Max, that initially had a very unpleasant hard sound. However, after used for about one hour, the sound improved and became decent. I believe this may be due to the filtering circuits needing time to adjust, possibly because of magnetization in the coil cores. My Topping PA 5 II in contrast sounded perfectly, right out of the box. Not necessarily the best amp ever, but considering price and size and energy consumption very good.

Above I posted my comparison to a CD Player. I noted a more lively sound with a CD Player which happens to be equipped with a linear power supply. That was for me noticable only with headphones. (I repeated the test today)
For me personally this is proof that the DAC inside the A6 is not the best possible DAC and therefor not 100% audibly transparent. So I take posts of people who notice a more lively sound after upgrading the powersuply seriously.But I also learned that the difference is not noticable in my speaker setup, so there is no rush to get the LPS.

 

An interesting read; waiting for part 3 if it is in the way...
You have actually chosen THE example.

Apart from the fact that I am technically educated, but seriously...
This is a deliberate theft. As are the power cables / interconnects / network switches / etc. etc. and such companies, IMO, should be brought to court for fraud.

 

@Alan Rutlidge
I really appreciate your effort on the topic "Does a LPS improve the sound of the A6?", but that is not what bothers me. What is really unbearable for me and other members is, that a member has undisputably a social competence score of zero and constantly shows severe behavioral issues toward other members.

 

you hit the nail on the head

This is exactly my point. Live and let live.
I don’t believe either in high end network cables, audiophile switches, fuses etc, but who am i to impose my view to others who seem to be happy with them. A friend of mine has such beliefs, we never discuss about it as we both respect our pov…..and we do spend quite some musical evenings together.

 

Without controls your comparisons are pretty much worthless, the two components must be level matched and you must not know which you are listening to.
The Dac in the A-6 is completely audibly transparent and therefore the ‘best’ available.
Set up a proper test, level match to .1dB and ask someone else to switch while you remain unaware.
To test ‘break in’ you need two identical components one used and one brand new.
Read up on cognitive bias.


Keith

 

This article specifically discusses the value of external power supplies.
https://www.audiosciencereview.com/...o-you-need-linear-power-supply-for-dacs.7021/
Keith

 

I didn’t think that for a minute, I just wanted to make it clear. No apology necessary.

 

IME and IMHO anything with mechanical movement can experience a change as a result of use. As you cited, loudspeakers and headphones are classic examples. I would also put phono cartridges in that category too. However mechanical components can also wear out and deteriorate over time. Bearings, motors, belts, pulleys and gears are also typical examples.

In electronics it's mostly electrolytic capacitors that deteriorate over time and as a result so does the performance. As the electrolyte dries out the capacitance normally drops and the ESR rises markedly. In some surface mount electrolytics produced in the early 90s the seals of the capacitors would fail and leak the corrosive electrolyte out all over the PCB and literally eat the copper traces and pads off the boards. If you catch it early enough you can usually save the PCB, but left undetected the only practical and reliable repair technique is to replace the entire PCB assembly and if you can't get one sadly the equipment ends up as landfill. This was a common problem with first generation DCC decks and other electronics produced on or about the same time. Fortunately modern solid dielectric polymer replacements don't have this problem. Electrical leakage can increase but this isn't just a problem in electrolytic capacitors. In paper and paper in oil dielectric capacitors the primary failure mode as they age is dielectric leakage and if left unchecked can lead to catastrophic consequences in tube equipment. In old tube tuners silver mica disease can cause noise problems too. There are certain film capacitors that go bad over time as well. Those older ones made by Rifa develop micro fractures in the epoxy encapsulation which allows moisture ingress to compromise the dielectric that leads to spectacular and often destructive failures. Us older techs have coined this "Rifa madness".

I restore and service a lot of vintage audio equipment and one thing some techs overlook is the thermal conductive paste used to conduct the heat out of power semiconductors to the heatsinks they are mounted on. This thermal paste eventually dries out over time and starts to become a thermal insulator rather than functioning as a thermal conductor. This can lead to the premature demise of output transistors as the device temperature increases to the point of destruction.

Other components that wear out are switches and potentiometers with rotary encoders typically used in modern gear not too far behind. Nothing lasts forever and in consumer equipment the problem of component failure is on the increase rather than on the decrease. Many manufacturers no longer specify nor equip high quality components with a high MTBF rate in their devices. The consumer is unfortunately driving this trend as we have developed this throw away won't be seen dead with last year's model mentality. In the eyes of the manufacturer this is ideal as it means there's always going to be an ongoing market for their products as long as they don't fail inside the warranty period or too shortly thereafter. Good quality parts can still be sourced but they come at a price and are not always locally available.

Regardless of if we like it or not I feel that we will eventually see the decline of "linear" power supplies as environmental /energy efficiency regulations become more restrictive. Manufacturers marketing their equipment in some countries now have to comply with stricter energy efficiency and standby power consumption regulations. For the most part SMPS can economically satisfy these legislative requirements whereas their LPS equivalents probably can't at the same cost or efficiency. It's a simple fact that linear regulators and low frequency (50 / 60Hz) transformers dissipate heat and are less efficient. LPS are also heavier and take up more space inside the chassis for the same power delivery capacity. But IMO they have their virtues and for 99% of my own designs I prefer a LPS over a SMPS for safety and noise performance reasons. Sure, SMPS have their applications and can work extremely well in a device that doesn't require a very low noise power supply.

 

@alan thank, you, this was very interesting. You forgot the the belts in record and cassette players. I already lost 1 record player and 2 cassette decks to "old age" this way.


According to the topic it would be interesting to elaborate if, why and how noise from the powersupply can influence the output of the DAC. The Noise can come from the connector, but can also be (more likely) inductively transmitted.

For low frequency noise this is quite obvious, but possibly the larger problem is the high frequency noise, which only a switching powersupply can produce.

I don't know how a DAC chips work (well, resistor ladder I understand) but I would assume internally it works with upsampled data at a fixed, quite high frequency. During the required downsampling, any noise will be equaled out, but from image manipulation I know, that this also softens the "edges". Maybe such softened "edges" are sometimes audible, but never with test signals, where you just have a single frequency. I am just speculating ...

The article on ASR https://www.audiosciencereview.com/...o-you-need-linear-power-supply-for-dacs.7021/ seems to be irrelevant since it does only test with external power bricks. This leaves the factor induction completely out. And thinking that the switching power supply utilizes a coil running at a high frequency, induction can be a problem. Maybe we can have the benefit of a linear powersupply in the A6 by simply building in a grounded metal plate between the 2 circut boards. Just thinking.

 

If there was any power supply noise ( caused by poor design) it would be evident in the measurements of the component taken at its output.
Keith

 

So, are there any others that have upgraded to the LPS-A6 power supply?

I would like to hear your impressions and experiences.