From my experience, my headphones (and earbuds) sound a lot better if I simply put passive 10 dB attenuators in the line after the final power stage. That cuts the noise floor by 10 dB, and the 10 dB of signal loss is easily made up for by turning up the volume! If I can sit in a quiet room with the source volume control turned all the way down, and give my ears a minute or two to adapt to the quiet, I should not be able to hear any background "hiss". If I can hear it under those conditions, that means I'll be struggling to hear the quietest nuances of the material I'm listening to. The obvious response is to turn up the volume to achieve a suitable SNR, but that has been proven to lead to hearing loss. Try the attenuators! If you're anxious about the inefficiency of resistive attenuators, I've also used a 1000:8 audio transformer (notionally lossless) to suppress the noise voltage. If the power amp is seeing a 1kohm load, it's loafing to produce the required voltage.

I researched his design(after all he went absent after license for about 4 years now....... the license isnt valid anymore..

Following the footstep of nwavguy and adrg for objective 2 Amp.

I replaced it with hi fi components with increased decoupling etc(to make it simple and easy).

Voltage amplification done by burson audio supreme sound v5D

And o2 booster board attached by adrg.

A new DC filter circuit on power socket and battery outlet with 2000mAh 9V slim profile NiMH
..........

Those audiophiliacs should know about benchmarkaudio series

If i compare benchmark HPA 2 headphone amp, the new o2 is near to it

BTW, see above: "...The no-derivatives clause makes perfect sense. The designs are inextricably linked to Nwavguy, so of course he doesn't want subjectivist nitwits releasing versions which underperform his properly engineered and tested designs.

While I'm at it, you think his license has "expired" on the basis of what evidence exactly? I missed the part where it could possibly have expired even by now: "...Licensor hereby grants You a worldwide, royalty-free, non-exclusive, perpetual (for the duration of the applicable copyright) license to exercise the rights in the Work as stated below"

https://creativecommons.org...

...and you tested your genius modifications and "compared" the results with the HPA2 how, exactly?

#MissingThePointEntirely

Fascinating story, but two things here:

1) His designs fail the Open Source Definition due to the ND clause, so they are not technically open source.

2) It would be trivial to re-enter these designs in your EDA software of choice, modify and issue the files output under whatever licence you please. This would not, as afar as I am aware, be in violation of any of his rights (unless the designs incorporated patented inventions).

(For the record, the "I am not a lawyer" caveat applies here)

See above:" No, they do not. Can you freely obtain the schematic and PCB layouts? Yes. Then it is open source.

"The no-derivatives clause makes perfect sense. The designs are inextricably linked to Nwavguy, so of course he doesn't want subjectivist nitwits releasing versions which underperform his properly engineered and tested designs."

https://creativecommons.org...

I like to think that NwAvGuy is a pro audio designer who doesn't want to expose his (successful) *real* high end pro audio background. High end pro audio is "clean" and "accurate" and while it costs quite a bit more than consumer equivalents, they're definitely less expensive than the "quack exotics" that mark up their costs over a thousand percent. I know most high end pro audio guys often refer to audiophiles as "audiophools" and they often point out many of the criticisms that NwAvGuy has in the past. He seems to be very familiar with recording equipment (including knowing details about a few "prosumer" brands that are mostly familiar with recording enthusiasts).

Domains can be renewed automatically. As long as the credit card is alive.

WELLLL having been around EE design work for over 40 yrs. This reminds me of many a story from my days in the 70's designing such amplifiers. I like most professional EE's would read the product reviews in the high end HiFi mags and they would just about make me throw up. As I would say this gueye of crap would drip off the adjectives, used on the pages like pollution. Even today where tubes are currently all the rage as preamp again, we all know they work much better if the glow in a Plexiglas cover on a bright chrome Macintosh Style chassis. ???
My best story is from Bob Pease who is of the older generation of analog wizards from National Semiconductor and who was lucky enough to work around the likes of Bob Dobkins and Jim Williams, who did stuff with analog IC's that was not suppose to be possible. ?
Some Great Humor Here:
Bob was in the Washington DC area giving a seminar on the old topic of temperature stability of Op amp designs. After the lecture in a conversation, he agreed with me that the audio and stereo business was out of reality and had waay to much BS. He then told me a story of how a very prestigious audio EE design society, had asked him to do a presentation at their annual meeting in Michigan, on the differences in performance of various hi end speaker cabling systems.
So he tested in his lab various, heavy braided cables with heavy pure brass connection termination lugs, and other with supper twisted gold plated wire and lugs. He then presented the frequency performance charts, for the five different cables sets, without identifying which chart went to which cable set. The five charts shown were rated from the best with almost a perfectly flat response from 5 HZ to 50KHZ for the top 2 cables, to the other 3 cables, where their was a some what hardly noticeable drop off at the high frequencies. After much debate over the chart results, he then shown them the name of the manufacture of the cables and their models, for each of the charts. The top rated #1 cable by performance that was really flat on frequency, was the gold plate twisted pair cable. It was then pointed out, that their was only a less then 1% difference in performance of the #1 cable from the #2 winner,.
and the #2 cable set ??? was a set of cheap $4.98 car jumper cables from Walmart, complete with the ultra thin copper flashing on a thin #12 steel cable

OH MON DIEU C'EST IMPOSSIBLE. But this is impossible
They all declared. And of coarse told Bob that he was crazy and he must have made an obvious mistake as their could be no way, that a $4.98 cable could be as good as a gold plated $89 set of speaker cables. They almost had the guts enough to called him a liar. Enough later dudes.

What a GREAT story. Thanks for posting this.

I saw an O2 review, I think it was headphonica. The reviewer did not like it. An "anonymous" commentator kinda calmly and very scientifically kinda tore the reviewer apart. Saying that he didn't like the lack of coloration or the lack of bass. The o2 gives you what mixers put on the CD (mp3, flac, whatever). anyway... it sounded very familiar to Nwavguy coming out of the wood work to defend his baby.

Haha... That was me! I don't know Nwavguy personally, and I never had the privilege to interface with him about his designs. However, I am an engineer and I am a proponent of his ethics and ideals and so it irks me when other seemingly "respectable" engineers resort to audio alchemy to describe a science. Let music alone be the emotion and energy to the soul and let the equipment be the wide open window for letting it pour in.

As someone who does not make much money but loves headphone gear as a hobby, it very frustrating to shop as much as it is fun. "Pros" hate this for this reason or love it for that. However it is some 100% subjective reason. I mean... I think he said he didn't like the DAC because it moved around on his desk?! Are you telling me that if the worlds MOST advance DAC ever made was the size of a USB thumb stick you would take off points? I can past comments like that. It is other things, that as a novice I can't tell are subjective or objective or total BS. The highs roll off into the lower sub bass. Man... I have no idea what that means. Some people hate this dac or amp because it doesn't color, other love it because it colors a certain way. So much of this hobby IS subjective, but there is an objective side that totally gets swallowed up and lost in all the crap.

The most surprising part of this article, to me, is that NwAvGuy was able to communicate in anything less than 10,000 words.

How do you know what NwavGuy's race or ethnicity is?

I herd he in now on a project called "oasis"...

An end game reference designed dac/amp..
Utilizing a new conductive component design..

Called "ExI power tracking" for the signal,
A signal transmission using no direct signal connection from inputs.

Also "inductive transmission" supply using no storage capacitance for an "absolute zero" pure power with no a/c interference..

Then the triple DAC will introduce a 3D mirror topology said to simultaneously address current, voltage, and power delivery into the resulting signal.
In simple terms, addressing and assuring the utmost detailed signal, not only from a digital perspective, but from an "analogue output" perspective..from three "mirrored DACs..
Summed into a Triode Tube preamp stage..
Into a discrete solid state device specially ordered to exhibit large voltage parameters...
It will be a powerhouse.

Specifically intendid to be sold at a low profit margin to upset and kill all competition and cause major kaos in HiFi community...
That day will be called the "Wrath of NwAvGuy"..

Then again I could just be making all this up...

I did a HD Audio driver. Only worked on 1 out of 5 machines and not in VM. It made my API ugly. I removed it and swore never to do a PCI device.

There are two "high end" audiophiles at work. One is half deaf, the other holds some crazy ideas about vacuum tubes.

And who exactly is this in reference to? XD

CC BY-ND is *not* an open-source license. Open-source licenses by definition allow derivative works.

Perhaps I should mention that I was a member of the board of the now disbanded Open Hardware Foundation. We tried, we didn't succeed and so we moved on with our lives. I hope that someone else will pickup the torch someday and if so, I would still like to help.

http://p2pfoundation.net/Op...

One of the first things that we were doing was to design a specific Open Hardware License so people didn't have to make do with licenses that were designed for software and other abstract works.

I suppose that it depends on the definition of a derivative work. There is nothing about the amplifier circuit that is unobvious (to use the term of art) to an electronic engineer so it could not even be copyright although the power circuit probably could be. And, I think that that is his point here that no fancy circuitry is needed at all to produce excellent results because excellent low cost gain blocks (IC Op Amps) are available.

The circuit does have some remaining issues. I might consider the issue of the input level a bit more. As another poster pointed out, there is a standard level. But, if it would also be operating with non-standard levels, an adjustable input level (screw driver slot pot) adjustment on one position of the switch might be a good feature.

I presume that the series output resistors on the paralleled op amps are there to guarantee stability since I have read many spec sheets that suggest that (this data sheet has no applications information). If they are there also to balance the load, the circuit could be improved a little so that part of the resistance was inside a feedback loop to further lower the output resistance at the cost of 4 more resistors per output op amp. And, then a small capacitor for each would improve stability since there is no need for frequency response all the way to 8 Mega Hertz.

According to his documentation, the series output resistors are there strictly to balance the load.

Yes, they do. Check out Open Source Definition at https://opensource.org/osd whose section 3 says that an open source ‘license must allow modifications and derived works, and must allow
them to be distributed under the same terms as the license of the
original software.’

No one disagrees that BSD-style licenses are open source.

And OSI is not some random group. It’s the group that coined the term ‘open source’. So if anyone knows what it means, it’s probably them.

You’re comment doesn’t contradict anything I wrote.

You’ve entered computer field in 1980 and yet you’re completely ignorant when it comes to FOSS licenses.

I disagree... you are misunderstanding "open source" with "free as in freedom" licenses. It is open source as long as you can have the source. It is free if it respects the basic freedoms of the user as described by the GNU.

You may disagree but that doesn’t make you correct.

From licensing point of view, free software and open source are the same thing. Check out https://opensource.org/faq#... which explicitly says that ‘“free software” and “open source software” are two terms for the same
thing: software released under licenses that guarantee a certain,
specific set of freedoms.’

That is just plain false. You can release your code yet don't allow compilation of it without a license...

You can do that but then it’s not free software/open source.

It is open source for sure, as the source is open. It is not free software as per the free software foundation definition.

A license under which you acquire the source, but your freedom to modify or redistribute it is limited, is generally called "source-available" rather than "open source".

Curiously while it can be said that the amp is "open hardware" because schematic and fabrication file is public, and the term has different criteria from "open source", it's not "open source" because the fabrication file is a compilation product from the EDA project files, which are not public.

That is not true. There are open source licenses that are not free software. Ask Richard Stallman.

No, there aren’t. You’re probably thinking of permissive licenses but those are recognised by FSF as free software. Take a look at FSF’s list of licenses and you’re find various permissive licenses.

Yes, there are, you are mistaken. You can even write your own license if you want. Not all open source licenses are FSF-approved, even.

BTW, his internet domain has been renewed again (2014-03-10)

Nowadays, renewing a domain name doesn't really mean you are alive! As long as your credit card still has balance, the registrar will renew the domain name for you automatically just a month before it expires. Even your web server can continue running in this way many years after your death, if it doesn't suffer a system problem. Personally I've seen an example of this, like the walking dead... TL;DR, It's hard to distinguish the work of a human and the work of a robot nowadays.

To avoid this issue, I strictly manually issue and renew my HTTPS certificate of my personal website. If the certificate expires for an extended time, my readers can simply assume the owner is dead and free to takeover any of my published personal projects. It's a better way of communication.

I sincerely hope NwAvGuy is still doing fine somewhere in the north-west America.

I pretty much have quit the audiophile world after determining it is a faith based cult. Trusting 65 year old writers to tell you how something sounds is insane,

And not only are these cults devout, but they don't suffer apostates gladly.

While maybe not quite a smoking gun or message in a bottle, a series of posts that proved to be his last at the popular Head-Fi site is revealing. The mechanics of notoriety are laid bare when NwAvGuy diagnoses what he calls a potentially serious flaw in an amp sold by one of the forum's sponsors. Headphones, he asserts, can be damaged. After much angry denial of his claims by a forum moderator, the manufacturer actually steps forward to man up, admit its mistake and make amends. All's well that ends well?

Not exactly. It's witch-burning time:

http://www.head-fi.org/t/56...

Mostly because they're all deaf.

or you could try stuff out urself?

Do it all the time. Do you hear wires?

If we are talking guitar cables, then yes. I don't pay for Mogami pre-made, but I do build my own and I am also a Jr in EE and an IEEE member. Although I would rather try different tubes in my amps than change the cables, lol. I look at cables like tires, would you put a Ferrari on the road with the cheapest tires offered?

That's a spectacularly bad example as tires have an extremely wide gap between the best and the worst and it's easily quantifiable via lap times or skidpad figures.

"High End" audio is very similar to Holistic Medicine.

In the case of Holistic Medicine, it starts off with some common sense concepts, such as taking a wider view of the entire person, and being not too narrowly focused on just the medical condition. But then it descends into madness and lunacy such as the "Memory of Water".

" High End" audio seems to follow the exact same path. And ends up in the same sort of madness and lunacy.

I hope that this clarifies the situation and helps to draw some victims back from the depths of insanity.

designs are textbook, so.....

I was referring to the broader audiophile community and its lack of scientific rigor. The undocumented "sound" of speaker wires, high end power cables, and even of wire "risers."

It has been said of the "Golden-Ears" crowd that often it is iron pyrite (fools gold) that defines their ears.

this article is about personalities, NOT engineering design.
The design is generic, simplistic, not genius.