[bhobba]

Check out:
http://www.edn-europe.com/powerthistestingaudioics+article+587+Europe.html

'But a serious problem remains. "It can happen that an amplifier measures well and just sounds bad," admits TI's Belnap. This statement does not in any way side with what many engineers consider to be a delusional movement among high-end audiophiles - the sort that demagnetizes vinyl records and seeks out hand-braided, gold-plated "unobtainium" speaker cable. It is rather to admit that the human ear is so sensitive and adaptable that there is no one quantitative test that can predict how a given DAC, amplifier, and speaker combination will sound to experienced listeners. This reality has already struck high-end-audio-IC vendors."At the high-performance end of our market, we used towalk in with sample parts and spec sheets and show customersthe data," relates National Semiconductor's Bridges. "Butrecently, more customers have been asking us to leave thespec sheet at home and bring in a working reference design.They take it right into their sound room and start listening to it. At the high end today, quality is all about how the chipsounds."'

If only they stared that years ago.

Thanks
Bill

[AKSA]

Yippeee!!!

I'm feeling better already!!!!!!!   

Specs are handy, listening is essential.....

Hugh

[Greg Erskine]

Hey Hugh,

Is there a business opportunity for you at National Semiconductor. I bet you could take a "working reference design" and make it sound fantastic ! 

regards

[AKSA]

Greg,

Only for EEs........

and under forty at that......   

And no accents here, please!!

Cheers,

Hugh

[Greg Erskine]

Only for EEs........

and under forty at that......

Hugh, they have already admitted a problem in selling by just the specs. "Employing a mature consultant with horizontally compatible credentials would be the right way forward in the future".

Imagine if all mid-fi systems, boomboxes, car radios and TVs sounded like AKSAs. That would really be nirvana.

[bhobba]

Specs are handy, listening is essential.....

And National have put their money where their mouth is:
http://www.edn.com/blog/1700000170/post/790011279.html

I new there was a reason the new lm4562 usually smoked everything else in blind listening tests.  Yep - you will find some guys prefer other chips, but I did a though internet search, and the concensus from pro audio guys was the new LM series lifts a number of 'veils' in listening tests and is comparable to a good discreet design.  Even if you never use a product with one of these op-amps, chances are in the future it will be mastered on equipment using it.  In a certain sense looking for ultimate performance at our end is defeating - you are limited by what it is being fed.  That is why I am more than happy to use equipment with this IC in it - used appropriately of course eg although good for I/V conversion I have read discreet stages still have the edge - but for filters and buffers - hard to beat.

Thanks
Bill

[bluesky]

Subjective, objective.........

The good folks at Australia's Silicon Chip magazine released a design for a preamp to match their new 20 watt Class A amp.  They wrote that the new opamp based preamp had specs that went beyond anything before with a large number of zeros in the specs.

Then a month or so later a reader picked up that the preamp had been dropped.  Silicon Chip then stated that the preamp just didn't work well enough and sound good and dropped it.

The magazine idolises the objectivist designer Doug Self, with good reason too in my opinion.  However, I've read one of Self's articles where he stated that anything below 0.001% distortion is inaudible.  Therefore Silicon Chip's assertion that their Class A design is better than anything else doesn't seem to hold water with me.

Thorsten Loesch's website has some interesting reading on clinical research which showed that the human ear canal somehow cancels out even order harmonic distortion.  Another good read is an interview with Pierre Spey from Mapleshade Records on TNT.  The gist of it was that Pierre had access to a super computer when he was a consultant of some sort to the US military and other government departments.  Pierre tried to model music mathematically with the super computer.  The computer simply fell over because of the complexity.  Since then Pierre uses his ears most of the time.

Bluesky     

[Geoff-AU]

Silicon Chip then stated that the preamp just didn't work well enough and sound good and dropped it.

SC have a problem with measurbating, despite (rightly, IMO) idolising Self they are not on the right track with their designs.

[AKSA]

Geoff,

That's an elegantly onanistic descriptor, wonderful!!

Have you visited diyaudio.com?  In the SS section they have several industry notables, including Robert Cordell and one exceedingly difficult young man from Sydney called Kleinschmidt, who are obsessed with error correction and various other circuit blocks and tout 0.00022% distortion at whatever as though it were a badge of honor.  Sadly none of them appear to actually build anything, it's all LTSpice.

There are a couple of very competent people there too, it's a fascinating forum, but the attitude is intensely adversarial. Essentially, it's a academic fight, with all that this implies.

Cheers,

Hugh

[bhobba]

However, I've read one of Self's articles where he stated that anything below 0.001% distortion is inaudible. 

IMHO it is inaudible. But its low distortion is not why people say the LM series is more transparent - IMHO it is speed - demon speed.  And the fact is was designed using listening tests.  Some say all people are hearing is the extra noise introduced by its wide bandwidth.  The guy at logitech stated it outright - he used the NJM5534 as the output for the transporter because it had lower measured distortion and a cheap electrolytic coupling cap for the same reason.  He thinks those that believe other components sound better are simply deluding themselves.  Sad really. 

Thanks
Bill

[AKSA]

Wayne at Bolder Cable will tell you - and I agree as I've heard it clearly in listening tests - that a teflon in the coupling position on the SB makes a huge difference.  And I've heard same on the GK1 preamp - and converted two now to teflon and they are much smoother with more resolution.

It is related to the dielectric absorption.  They say the difference is not measureable, but the dielectric absorption is the key as delayed release on a cap due to this phenomenon causes time smearing - which shows as 'grainy' resolution.

This technology is like just about everything in that it is subject to fad and fashion, just like medicine, art, education, music, the list goes on.  And the fact that feverish marketing departments are obliged to use fancy, pseudo-science pop names for 'features' (and I'm in this game too with a recent discovery of 'pure current drive', whatever the heck that means.....) has not helped this populist, obfuscating trend in modern consumer electronics.

Cheers,

Hugh

[Geoff-AU]

Hi Hugh,

I have been to DIYaudio forums, as you say it is a great resource as there are a lot of technical tidbits.  However, the people on there cross swords at every opportunity and reading their debates gets tiring after a while.

Geoff

[Seano]

Imagine if all mid-fi systems, boomboxes, car radios and TVs sounded like AKSAs. That would really be nirvana.

  Oh no it wouldn't.  That's like saying if everything tasted like food from McDonalds then it'd be great too.  NoOOOOOOOoooooOOOOOoooo

If everything sounded like an AKSA then I'd be forced to buy a guitar and try singing for my own entertainment.  The joy of the AKSA (and all the other audio jewellery out there) is that they DO sound different - beauty is in diversity.  In similarity, there is only greyness and death.

Which goes to explain why I take some quiet satisfaction in the existence of two different schools of audio measurement........it ensures diversity.

[Greg Erskine]

Hi Seano,

You raise a very good point, but please.... can my friends mid-fi systems sound more like an AKSA. I spend a lot of time visiting and it can be painful biting one's tongue. 

[Seano]

In order to cope with other people's mid-fi I find it helps to take a deep breath, ask for another beer and walk outside.......then ask for another beer.  Funnily enough you stop caring how average it sounds quite soon after that.

Let's face it...if they don't care how it sounds then why should I get stressed about it? Who needs more angst in their life? Certainly not this little black slime mould!