New Linear Power supply upgrade for DMP A-6

I am not asking you for evidence.
The problem is that people makes these claims without any evidence, they are no different from fairy stories and without evidence should be regarded as such.
Keith

 

I tend to agree with both @Purité Audio and @_Richard_ I know that sounds contradictory in some aspects and "fence sitting" on the other, but IME opinions are just that - opinions. Some are based on facts and others on purely subjective impressions.

Whilst I tend to lean towards opinions that are or can be substantiated by fact, I do feel a bit uncomfortable at times completely dismissing subjective (but hopefully unbiased) opinion as there may be situations where what someone hears differently may be something I either can't hear or have missed in a critical listening analysis. Everyone has different perceptions, even if only minutely on just about everything. As one member commented in a thread, you should take a visit to some of the coffee forums to see real subjectivity in action often escalating to the point where things quickly get so heated that they aren't roasting the beans they are literally cremating them and each other.

In my many years of having a keen interest in high quality audio which dates back to my mid-teens I've been on the never-ending search for audio nirvana. On that journey I will fully admit to falling for a lot of hype and what I latter realised to be over exaggerated claims. I'm a firm believer that hearing is believing if the opinion formed by hearing something is completely objective and unbiased. Unfortunately there are many forms of bias that we as individuals forming opinions are likely to dismiss (even unintentionally). These are brand bias, cost bias, expectational bias and pre-conceived bias possibly based on previous experiences both good and bad. Now this might sound strange at first, but please bear with me for a moment as I elaborate on my statement.

When I design, repair, modify or test a piece of audio gear I do listen to it extensively. I also electrically test it exhaustively too. From time to time an amplifier, preamp or DAC finds its way into my workshop for repairs. The attached note saying something vague like "It doesn't sound right" and nothing beyond that and often dialogue with the owner doesn't always elude to any more useful information. If it's an integrated or power amp I will do a few preliminary tests to ensure that it doesn't have some issue which are likely to let the magic smoke out of the test speakers. If everything appears to be okay I'll have a brief listening session to see if I get any audible cues as to what the owner has said by "It doesn't sound right.". More than often (but not always) the problem is quickly realised and a proper electrical diagnosis can proceed from there to isolate and rectify the problem. When conducting electrical testing, one can often "see" what is contributing to the issue the person was describing, because IME if it tests faulty it usually sounds like crap.

So, do measurements matter? IME and IMHO, yes they do. They take the subjective bias out of the equation. IME, if something measures poorly it's likely to sound that way. With modern electronics manufacturers are for all intent and purpose capable of designing and building to the state of the art. Of course, not all manufacturers are going to do this and it's quite evident that most mainstream manufacturers for the best part design and build to a price point and not always to achieve the best possible performance if money was no object. It's the nature of the industry which to me makes perfect sense. R&D costs time and money. It's got to come from somewhere and it's often the high volume lower cost products that fund this. Also, manufacturers must turn a healthy profit in order to remain viable so they can continue their R&D and therefore develop better and more cost effective products in the future.

The issue I see with uncontrolled subjective testing is that electrical influencing characteristics are rarely taken into account when evaluating audio equipment. A typical such situation arose more than a decade ago when one of my fellow audio enthusiasts purchased a new power amplifier. His first listening impressions were "It's got no bass. . I've spent all this money on a high-end product and it sounds like crap." . Not wanting to put this 50kg monster back in its shipping crate and send it back clear across the country at great expense he asked me to take a quick look at it to see if I could identify what the problem was. I put it on the bench and during testing I could not fault it. A perfectly flat frequency response from d.c. to well over 100kHz, extremely low noise and distortion from a few mW of output power to its full rating of 350W continuous per channel with both channels driven across the entire audio band. So what's wrong with this power amp that made it sound so awful? Well nothing actually. The power amp just happens to have a much lower than usual input impedance. About 1000 ohms compared to the typical 20,000 ohms or higher that most power amps present. He was driving the power amp with a preamp that had a comparatively high output impedance which was a poor electrical match for this particular power amp. Audio design theory suggests that the source impedance (the preamp) should ideally be at least x10 lower than the load impedance (input impedance of the power amplifier). In this case it wasn't and this resulted in a significant roll off of the bass response when used in combination. As the frequency gets lower, the capacitive reactance of the output coupling capacitor of the preamp rises and this gives rise to the output impedance at bass frequencies. As the source impedance rises this results in less drive voltage being available to the power amplifier and because of this the bass response suffered. So what was the solution? Get a preamp with a much lower output impedance. He ended up buying a preamp that had a very low output impedance of 10 ohms which swapped the impedance ratio to a very favourable 1:100 and audio nirvana had returned along with the bass.

This is just one example of why specifications matter. Standing alone the power amplifier and the original preamp were superb, however they were not a good electrical combination. Novices and those with little or no technical knowledge can be challenged by situations similar to that I've just mentioned. It only goes to reinforce my opinion that you have to listen to the components you intend to buy in combination with the equipment you already have and intend to keep in the absence of a technical understanding of the possible problems you might encounter. Because a lot of subjective opinion rarely takes into account the possible electrical incompatibilities of equipment some gear can get a bad rap for all the wrong reasons. BTW, just be perfectly clear, I'm not of the opinion that all amplifiers and DACs sound the same because IME they don't.

 

@Alan Rutlidge
Alan, i really must hand it to you. This is by far the most irreproachable admission on this topic i have encountered so far.

 

@Alan Rutlidge chapeau, this post is gold. Nothing like those disrespectful zealots sounding like broken records repeating the same things over and over aging

 

I was referring to the review of the forum member @13thNote
FiiO R9 Vs FiiO R7 (Compared to Eversolo / Cambridge CXN100 / Bluesound) (youtube.com)

I believe that a well-researched and impartial review holds more significance than a story from over a decade ago. Personally, I have never been interested in the R7 or R9 due to its design and touch operating system. However, I find it intriguing that there is a device that allows you to change the power supply without shutting it down.

I appreciate Alan's courteous comment above a lot and can also understand that there is probably a significant amount of marketing aimed at promoting products that may not actually deliver on their promises. However, I am skeptical about whether this is the case for the "linear" power supply in question.

Why do high-end DACs utilize large transformers instead of the more cost-effective switching technology?

I don't think the frequency of the "mains" is an issue for the output. However, I can imagine that the high frequency pulses generated by a switching device could cause peaks that disrupt the digital-to-analog conversion process in a way that alters the sound quality, potentially decreasing resolution rather than adding noise. As I said much earlier, such pulses should be visible in the output of the powersupply. I think the measurement of a device should also check for such design flaws, to be complete.

 

Any measurements in that review or just more unsubstantiated subjective nonsense?
Again ( and again and again) look at the measurements if there is power supply noise it will be visible in the measurements.
Everything is there, you just need to learn and understand them.
Keith

 

Quote from Wikipedia:
"Psychoacoustics is the branch of psychophysics involving the scientific study of sound perception and audiology—how the human auditory system perceives various sounds. More specifically, it is the branch of science studying the psychological responses associated with sound (including noise, speech, and music). Psychoacoustics is an interdisciplinary field including psychology, acoustics, electronic engineering, physics, biology, physiology, and computer science."
End Quote
Everything is there, you just need to study and try to understand it.

 

@_Richard_ sorry, I find this lecturing inpolite. I don't see how I wrote anything about any audio "I" heard. I find this topic technically interesting, but it seems so I will not learn anything here.

 

I just wanted to state that there is difference between an audio precision analyzer and the human auditory system.
Actually it is very challenging for me to hear that measurement argument over and over again. Imho, that is unsubstantiated subjective nonsense, regarding human perception of music reproduction.

 

I found that relevant post on ASR:
Do you need linear power supply for DACs? | Audio Science Review (ASR) Forum

The conclusion is "It is clear that whether you use the USB power, or the supplied switching power supply, there is absolutely no audible improvement in the output of the DAC with linear power supplies.".
Interesting read.

According to "precision analyzer" havent yet found anything which measures the much discussed "soundstage" or "depth". That may be the Psychoacoustics you were refering too. But I am not entirely convinced, since I think the testing is flawed in the way, that just a test signal is analyzed.

I am not really an audio person and very happy with what I have. But I do a lot of image manipulation and there you have the "color science" and "3d effect", which referes to qualities of a camera or lens which cannot be prooved. But they are still an important factor for the fun you have with your images. We pay a lot of money for lenses, sometimes not to get the most accurate image but to get the most pleasing or different images.

 

https://pd-cf.com/produkt/eversolo-dmp-a6-lownoise-psu-ea6-upgrade/

I didn't know that we had also attracted the attention of venerable PD creative

 

I'm reading the whole topic that I hadn't read, I miss this as I've never needed it, can you put an Amazon link? I have a CD player and a hard drive. Ty

 

Worth remembering that what comes out of the dac is only a modulated voltage
Amplitude and time or amplitude and frequency completely characterise the signal, no ‘soundstage’ information!
Speakers/room and programme for image.
Keith

 

I use a USB3 hub obtained from Amazon UK under the brand name RSHTECH, a four port device with individual push buttons to connect/disconnect individual ports and has small blue leds to tell you which are on at a glance. It comes with the necessary USB3 cable about 1m long and should be connected to the top OTG port on the A6, the setting for that port should be mass storage. It also comes with a SMPS wallwart power supply and cable to power the hub, rated at 5V 2A, cable length short at 1 m. Model number is RSH-516. Amazon also has a similar model with more ports if you need it.

 

Thanks, but I misunderstood, I thought it was a hub where I could connect each device's usb (a6 two usb ports) to the hub and manage them separately.
A sort of bridge/hub. Thanks anyway. Sorry for ot.

 

It is a hub, it physically connects via the supplied cable to the top OTG port of the A6. It expands 1 port to 4 separate USB ports which can be switched on/off individually. It supplies power to the connected devices which is important if you are connecting devices like external drives and optical CD drives which could otherwise overload the A6 current wise. The bottom USB port on the A6 is for USB Audio Out not really involved in this issue at all.

 

you're right, the lower port is actually connected permanently to the Saturn MK 3, sometimes I use its DAC, for fun, in fact it's only the upper port that has the possibility of connecting CDs and harddisks. Great.

 

Since I don't have anything to do, I'll act as a guinea pig.
I will take the Polish power supply, it worked wonders with the node, but the node one was poor, I don't expect anything.
I will send my master edition and power supply to the meter of a well-known Italian forum, and all the measurements will be carried out, a few more than those of Amir, so as to see the differences between the smooth and the ME, obviously net of the different control equipment measure, but we might have an idea.
File return and environmental measures before and after modification are not excluded.

 

I just installed the LPS-A6 and I have got to say that it makes a huge improvement in my system. A lot of the claims about increased soundstage, separation, detail and removal of that little bit of a harsh top end are justified.
I'm using the DMP-A6 as a transport connecting USB to my DAC.

Before I installed the power supply, I listened to Dire Straits song Down to the waterline, where some places the distortion on his guitar was annoyingly tinny and screechy, so that's what I was listening for after the install to see if it took the edge off.

Boy, was I in for a surprise. The first thing I noticed was the kick and slam of the drums, and there was a really nice texture and decay. Voices were intimate, articulate and also nicely textured. The highs were high and clear. Also the soundstage filled out in width and depth. Triangles sounded like they were way beyond the left speaker. The sound really became more lifelike. And I totally forgot about what I was listening for.

I was also a skeptic about the influences of electrical power in a sound system a few years ago, and I still keep a sharp eye on products that claim this and that. But this I can not deny. For me, in my system, in my room, upgrading the power supply made just as much of a difference as buying new gear, no joke.

 

Great anecdote, let me guess you removed the old power supply and then ( however long it took) listened to the new set-up?
Keith