The Best for the Least

[plissken]

15 minutes ago, BobSherman said:

You do not realize this but all this testing is being done by a relative  incompetent.  There is no real correlation to sound quality. But keep measuring if it makes you boys happy. As far as the Schiit product bashing goes it not based in reality, but just a creation by an unhappy few.

 

Sorry I didn't know Amir was a relative incompetent. I've included the bio he put up at AudioScienceReview. I await yours in reciprocal since his incompetencies must simply be relative to your vast accomplishments. 

 

"This is a bit about your host, Amir Majidimehr. I am writing this as to give more context to people reading my technical reviews and measurements. I have realized that without this context, many assume I am yet another blogger spitting out graphs. That is very true but let’s see if we can confuse them with an alternate reality!

Without giving away my exact age, I grew up in 1960s with analog electronics as my primary hobby. Learned that from my oldest brother who likewise had the same hobby and spent his nights and days designing electronics. This gave me an intuition for analog electronics which to this day serves me better any textbook or formal education.

Speaking of formal education, I naturally aimed to get an Electrical Engineer Degree which I received in early 1980s (still trying hard to not give away my age!). During that time though, the personal computer revolution was upon us and I quickly fell in love with my second hobby: software. I programmed my Apple II and later managed the computer lab at the college where I wrote a bunch of custom software including an editor all the students used to write their programs.

During schooling, I worked at an electronics repair shop, fixing everything from audio equipment to VHF radios. That childhood experience really got cemented combined with a new skill of having to troubleshoot equipment, usually with no schematic. All in all, I repaired hundreds of pieces of equipment, getting a good feel for quality engineering versus not.

Back to the degree, once I graduated, the first job I found was actually software, not engineering. I became a Unix “kernel” (Operating system) developer working on then new, Unix operating system. That gave me another baptism by fire having to learn nearly half a million lines of code with nary any documentation. This was at a large minicomputer company producing systems costing nearly $300,000. Kernel work gets you pretty close to hardware and during that time, I got a very deep understanding of it. This was a good thing as Unix became the foundation for much of what we use today from Linux to Android, MacOS and Windows.

In late 1980s I had an opportunity to work at the computer division of Sony. Initially the job was building a software team to develop Unix but we proposed and won approval to design and build our own hardware to go with it. There we went deep, developing our own ASICs (large scale custom electronic IC), motherboards, audio subsystem, power supply, LCD display etc. Working for Sony was great as at that time they were in their peak of success and their quality standards were quite high. We combined that with great engineering from US in silicon valley and really pushed state of the art in design and simulation at that time.

It was during that time that I got exposed to products of a then new company, Audio Precision (AP). They had overnight obsoleted audio measurement products from likes of HP (now Agilent/Keysight). I bought one for the team but I was the only one who learned to use it. It cost a cool $25,000 which at the time (early 1990s) was quite a lot of money. Still is today.

Sony fell on hard times after acquiring Columbia Pictures so my team was let go. I was offered to stay there but I got bored and left. In return for some consulting though, I got to keep that original AP (which I later gave to my brother -- the unit I have now is much newer).

Having developed my hardware skills, the next two companies I worked for also developed hardware and software: Abekas Video Systems and Pinnacle (now part of Avid). There, I managed hardware, firmware and software engineers development high-end hardware for real-time effects, switching, graphics, editing, etc. I am fortunate enough to have managed a very smart team which won two technical Emmy Awards.

By then a new development was happening: the web. I had worked extensively on networking which was the underpinning of the Internet. The advent of browsers took that to a new level and I wanted to be a part of that. So when my ex-boss from Akekas called me to say he was leading a Stanford-university start-up that was streaming video on the web, I jump at the chance to lead engineering there.

This was in the days of dial-up modems and trying to send video and audio through such slow link was nothing short of a miracle. Still, we managed to do it well enough that the company got acquired by Microsoft back in 1997 (https://news.microsoft.com/1997/08/...timedia-strategy-with-release-of-netshow-2-0/).

I specialized at Microsoft in driving our technology through other products than just the PC. At the time everyone was the enemy of Microsoft it seemed so it was a big challenge. At the end, we did it with our products literally shipping billions of other devices and every Blu-ray player. Only Apple refused to ship and use it. To date, those products all generate significant royalty stream for Microsoft, long after I am gone from there.

During my time at Microsoft, as VP of Digital Media Division, I grew to manage a division of nearly 1000 engineers, testers, marketing and business development people. One of the groups I managed though was the signal processing team which produced audio and video compression technologies. Both of those relied on refreshing my knowledge of the core signal processing science back in college and learning a ton more about new domains like psychoacoustics. Formal and controlled testing was a part of that just the same. Through training, I became an “expert” in finding difficult audio distortions that many could not. This training is serving me well to this day in being able to pass audio objectivist challenges of blind tests of small distortions."

[BobSherman]

6 minutes ago, plissken said:

 

Sorry I didn't know Amir was a relative incompetent. I've included the bio

Sounds amazing, lol... but there are facts and then there is fiction.  Handing someone a scalpel does not make them a surgeon.

[plissken]

3 minutes ago, BobSherman said:

Sounds amazing, lol... but there are facts and then there is fiction.  Handing someone a scalpel does not make them a surgeon.

 

How many Technical Emmy's do you have on your C.V?

[BobSherman]

34 minutes ago, plissken said:

 

How many Technical Emmy's do you have on your C.V?

The CV is one of a manager, not technical and it shows when he struggles with relativity simple technical tasks. You can worship him as much as you want but when you carry his mostly clueless junk to the real world you will be challenged. His recent foolishness of claiming the  Emotiva DC-1 is dangerous because of the unused ground tap on the AC socket was pretty stupid when the unit is normally a UN-grounded 2 wire unit. Pure amateur assumption  to think just because the AC input has a unused tab the manufacture must be incompetent. He has a issue with business success, due to his lack of success. 

[plissken]

6 minutes ago, BobSherman said:

The CV is one of a manager, not technical and it shows when he struggles with relativity simple technical tasks. You can worship him as much as you want but when you carry his mostly clueless junk to the real world you will be challenged. His recent foolishness of claiming the  Emotiva DC-1 is dangerous because of the unused ground tap on the AC socket was pretty stupid when the unit is normally a UN-grounded 2 wire unit. Pure amateur assumption  to think just because the AC input has a unused tab the manufacture must be incompetent. He has a issue with business success, due to his lack of success. 

 

No, he's claiming it's foolish because the PCB assembly is directly pressed up against an AC line and he rightly points out they could have tooled out the production to move the board by an inch. 

 

I took the cover off of mine and certainly agree with his assessment. 

[The Computer Audiophile]

Anyone think to ask the manufacturer?

[BobSherman]

3 minutes ago, plissken said:

 

No, he's claiming it's foolish because the PCB assembly is directly pressed up against an AC line and he rightly points out they could have tooled out the production to move the board by an inch. 

 

I took the cover off of mine and certainly agree with his assessment. 

Here is is quote: 

"Immediately though, there is a major source of concern. Check out the IEC plug:

We have a 3-prong, grounded IEC socket but the ground lug doesn't go anywhere! It must be connected to the case as this is metal and an electrical short can energize it. Only a double insulated piece of equipment can be run on two wires. Which this is not.

This is a major safety flaw! I can't recommend purchasing this equipment on this basis!"

The red herring comment regarding the insulated wire touching the circuit board comes later.

[plissken]

6 minutes ago, The Computer Audiophile said:

Anyone think to ask the manufacturer?

 

Agreed. But I can't find fault with his opinion, yes it's an opinion, that the insulated wire is directly up against the PCB. Better care could have been taken. It's my opinion upon inspection also. I would like to see a bit more attention to detail paid. 

 

I guess the later IEC plugs are only two prong. 

 

I'm not disagreeing with the initial reaction as it has been talked about in thread about the unit could be indeed designed so you don't get electrocuted. 

 

Also of note only CE and FCC certifications and the meaning vs having it put through UL. 

[BobSherman]

17 minutes ago, The Computer Audiophile said:

Anyone think to ask the manufacturer?

Hi Chris,

 

Someone checked a picture of another DAC same model and it only had a 2 wire socket. Maybe they had stock of 3 wire IECs or punched panel prior to finalizing the design. Or who knows exactly why... But to assume that the manufacture is just being negligent is pretty clueless IMO.

[plissken]

2 minutes ago, BobSherman said:

Hi Chris,

 

Someone checked a picture of another DAC same model and it only had a 2 wire socket. Maybe the stock of 3 wire IECs or punched the prior to finalizing the design. Or who knows exactly why... But to assume that the manufacture is just being negligent is pretty clueless IMO.

 

Hi directly states he doesn't see it as double insulated. It's posited in thread that there may be another mechanism. I would too prefer that the question is asked of any vendor prior to posting the tear down as to have a definitive answer before jumping to conclusions. 

[BobSherman]

7 minutes ago, plissken said:

 

Hi directly states he doesn't see it as double insulated. It's posited in thread that there may be another mechanism. I would too prefer that the question is asked of any vendor prior to posting the tear down as to have a definitive answer before jumping to conclusions. 

"Some appliances, such as vacuum cleaners and electric drills, do not have an earth wire. This is because they have plastic casings, or they have been designed so that the live wire can not touch the casing. As a result, the casing cannot give an electric shock, even if the wires inside become loose."

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/electricityworld/mainselectricityrev4.shtml

 

The key word is designed.

SMH

 

[plissken]

Just now, BobSherman said:

"Some appliances, such as vacuum cleaners and electric drills, do not have an earth wire. This is because they have plastic casings, or they have been designed so that the live wire can not touch the casing. As a result, the casing cannot give an electric shock, even if the wires inside become loose."

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/electricityworld/mainselectricityrev4.shtml

 

SMH

 

 

Is that conjecture wrt the DC-1?

[fas42]

Worrying about electrical safety is not relevant to the matter at the heart of this - that we are still way off being able to derive numbers that correlate with the subjective SQ. Being able to produce figures might make some people happy, but not others - I have a 30 year old power amplifier which has spec numbers which would embarrass many current offerings, in terms of the detail given, and the values derived - but that didn't stop it having audible problems. If you can't fully characterise everything that matters in audio, then you ain't got sh!t !!! ...

[sandyk]

4 hours ago, BobSherman said:

Here is is quote: 

"Immediately though, there is a major source of concern. Check out the IEC plug:

We have a 3-prong, grounded IEC socket but the ground lug doesn't go anywhere! It must be connected to the case as this is metal and an electrical short can energize it. Only a double insulated piece of equipment can be run on two wires. Which this is not.

This is a major safety flaw! I can't recommend purchasing this equipment on this basis!"

The red herring comment regarding the insulated wire touching the circuit board comes later.

 Does it really matter whether you use a 2 pin socket or a 3pin IEC socket provided that the earth of the 3 pin socket is not connected ?

A 3 pin IEC plug and socket is far more robust, and less likely to have the plug fall out, although it is possible that this is not permissible ?  You also have a further advantage that some IEC 3 pin sockets also have an inbuilt safety type fuse holder.

[BobSherman]

6 minutes ago, sandyk said:

 Does it really matter whether you use a 2 pin socket or a 3pin IEC socket provided that the earth of the 3 pin socket is not connected ?

A 3 pin IEC plug and socket is far more robust, and less likely to have the plug fall out, although it is possible that this is not permissible ?  You also have a further advantage that some IEC 3 pin sockets also have an inbuilt safety type fuse holder.

Hi,

 

It does not matter to you or I, or probable anyone else with a functional brain, but the great tester in chief called the fire department and had them hose down the DAC!

[Spacehound]

4 hours ago, fas42 said:

Worrying about electrical safety is not relevant to the matter at the heart of this - that we are still way off being able to derive numbers that correlate with the subjective SQ. Being able to produce figures might make some people happy, but not others - I have a 30 year old power amplifier which has spec numbers which would embarrass many current offerings, in terms of the detail given, and the values derived - but that didn't stop it having audible problems. If you can't fully characterise everything that matters in audio, then you ain't got sh!t !!! ...

"we are still way off being able to derive numbers that correlate with the subjective SQ."

 

Of course we can. You just destroyed your own argument by mentioning 'subjective SQ'.

 

What someone thinks is good SQ is  entirely personal, as in  "Spacehound likes it but fas42 doesn't"..

 

No more than that.

 

But it you measure it, and find that it  (be "it" a DAC, amp, speaker, whatever) has low noise, a flat frequency response, low phase shift throughout its frequency response, and a high input impedance and a low output impedance so it will work well with whatever is in front of it and behind it:

 

It can't HELP but reproduce the source accurately.

 

Which, lacking the artistes in your room, so having to use a recording as your source,   is the very definition of 'good sound quality'  (hifi = high fidelity = accuracy = qood sound quality). Got nothing to do with whether you like it or not. If you don't then buy a different recording.

 

 

[esldude]

Then there are the Schiit Multi-bit Bifrost measurements. 

 

Hmmm, not too impressive either. 

 

https://www.audiosciencereview.com/forum/index.php?threads/measurement-and-review-of-schiit-bifrost-multibit-dac.2319/#post-63533

 

 

[GUTB]

2 minutes ago, Spacehound said:

"we are still way off being able to derive numbers that correlate with the subjective SQ."

 

Of course we can. You just destroyed your own argument by mentioning 'subjective SQ'.

 

What someone thinks is good SQ is  entirely personal, as in  "Spacehound likes it but fas42 doesn't"..

 

No more than that.

 

But it you measure it, and find that it  (be "it" a DAC, amp, speaker, whatever) has low noise, a flat frequency response, low phase shift throughout its frequency response, and a high input impedance and a low output impedance so it will work well with whatever is in front of it and behind it:

 

It can't HELP but reproduce the source accurately.

 

Which, lacking the artistes in your room, so having to use a recording as your source,   is the very definition of 'good sound quality'  (hifi = high fidelity = accuracy = qood sound quality). Got nothing to do with whether you like it or not. If you don't then buy a different recording.

 

 

 

Your opinions on this appear to be at odds with your equipment choices. If good measurements and impedance matching are all that matters, why did you get a Rossini? Isn’t that a huge waste of money?

[Spacehound]

23 minutes ago, GUTB said:

 

Your opinions on this appear to be at odds with your equipment choices. If good measurements and impedance matching are all that matters, why did you get a Rossini? Isn’t that a huge waste of money?

Next to the Vivaldi 'stack', which I couldn't afford,  it's the best measuring DAC that exists. 

 

And I like it's shape ,  and that most of their business is in studio stuff and military communications, so I know they have a clue. 

[esldude]

8 minutes ago, Spacehound said:

Next to the Vivaldi 'stack', which I couldn't afford,  it's the best measuring DAC that exists. 

 

And I like it's shape ,  and that most of their business is in studio stuff and military communications, so I know they have a clue.  

Military grade hifi..........................not sure that has the right ring to it for a slogan.  

[Fluffytime]

Carpet bombing resolution.

[Spacehound]

17 minutes ago, esldude said:

Military grade hifi..........................not sure that has the right ring to it for a slogan.  

The grunts like their orders clear, and they are not required to approve of them 

[sandyk]

1 hour ago, Spacehound said:

But it you measure it, and find that it  (be "it" a DAC, amp, speaker, whatever) has low noise, a flat frequency response, low phase shift throughout its frequency response, and a high input impedance and a low output impedance so it will work well with whatever is in front of it and behind it:

 

It can't HELP but reproduce the source accurately.

 

 

 You forgot to mention channel separation , which for highest performance needs to be much greater than we originally gave it credit for. A good amplifier can have all those other attributes, but construct it in a dual mono configuration with very good separate power supplies, perhaps with the front ends also having separate voltage regulation, and it will almost always sound more realistic with good source material.

Many are now finding that the use of VERY low noise PSUs results in audible and visual gains in almost all A/V gear.

Many are now obtaining improved results in different gear using  LT3045  .8uV noise voltage regulators, both for the digital and analogue areas.

Even replacing the generic high voltage bridge rectifier diodes in the SMPS of earlier DVD players with fast , slow recovery BYV26E diodes can result in a glossier more saturated picture when seen via a HD projector.

The use of very closely matched Differential pairs (HFE and VBE) in the front end of an amplifier can also result in very worthwhile improvements, despite the devices already being matched to within 1% !

The typical Current Mirror is the culprit here, because it doesn't take into account the bias current of the VAS stage transistor on only one half of the LTP.

 

http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion-15.html

[Spacehound]

40 minutes ago, sandyk said:

 

 You forgot to mention channel separation , which for highest performance needs to be much greater than we originally gave it credit for. A good amplifier can have all those other attributes, but construct it in a dual mono configuration with very good separate power supplies, perhaps with the front ends also having separate voltage regulation, and it will almost always sound more realistic with good source material.

Many are now finding that the use of VERY low noise PSUs results in audible and visual gains in almost all A/V gear.

Many are now obtaining improved results in different gear using  LT3045  .8uV noise voltage regulators, both for the digital and analogue areas.

Even replacing the generic high voltage bridge rectifier diodes in the SMPS of earlier DVD players with fast , slow recovery BYV26E diodes can result in a glossier more saturated picture when seen via a HD projector.

The use of very closely matched Differential pairs (HFE and VBE) in the front end of an amplifier can also result in very worthwhile improvements, despite the devices already being matched to within 1% !

The typical Current Mirror is the culprit here, because it doesn't take into account the bias current of the VAS stage transistor on only one half of the LTP.

 

http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion-15.html

It wasn't intended to be a 100% complete list,  nor did I want to go into the 'finer points' as while they are all very nice the topic is about getting a 'genuine' hifi system at low cost.

 

Which roughly boils down to:

 

Cambridge Audio  Dacmagic Plus ---> low to mid-price Onkyo amp ---> any speakers from the Monitor Audio 'Bronze' range.

 

If you want a turntable add  a used Technics SL1200 (and NO, I am NOT going to discuss this, I found  mine in the window of  a pawnshop next to the Star of Peking  takeaway  I was about to visit), any  cartridge you can find in a 'proper' hifi shop (half-decent cartridges now not being readily available on the 'high street') and the Cambridge Audio combined MC/MM phono amp as it doesn't cost much and will suit whatever sort of cartridge you can find.

 

Except for the turntable that's   just 'off the top of my head' so of course there are alternatives.

[sandyk]

19 minutes ago, Spacehound said:

It wasn't intended to be a 100% complete list,  nor did I want to go into the 'finer points' as while they are all very nice the topic is about getting a 'genuine' hifi system at low cost.

 

 You make a " definitive " statement then become evasive when challenged on it  ! 

 

I agree though, it is off topic.