Here it comes ... which are the "best" manufacturers, what colour works best, solid or with holes -- you get the drift ...I have placed a standard clay house brick on top of my cd player in the past and the added mass altered the sound. Rotating the brick 180* further altered the sound
Dan.
, ...Frank
Brickbats....
Haha Frank, no you are being wrongly cynical.
My thoughts are more along the lines of locked in magnetic orientation of the iron constituent in the brick causing some non linearity or bias in the sheet steel top cover of the cd player.
Perhaps others here could explain permanent magnetic fields influencing the behaviour of steel enclosures further to the information already given in recent posts.
Dan.
Here it comes ... which are the "best" manufacturers, what colour works best, solid or with holes -- you get the drift ...
Frank
Haha Frank, no you are being wrongly cynical.
My thoughts are more along the lines of locked in magnetic orientation of the iron constituent in the brick causing some non linearity or bias in the sheet steel top cover of the cd player.
Perhaps others here could explain permanent magnetic fields influencing the behaviour of steel enclosures further to the information already given in recent posts.
Dan.
Thanks for this Pavel.
I should point out that 5532/4 essentially has C2 built into its compensation with the same beneficial effects on distortion, particularly high order stuff like JC's 7th. It's one reason why its performance still rivals the new uber OPAs in real life.
Of course AD797 IS better in the correct application. As in all things, close attention to the CORRECT details matter; .. and are far more important than BELIEVING Golden Pinnae myths. Correct choice of device for the task is one of the important details which pseudo gurus often don't understand.
eg. 5532/4 will outperform the AD797 in the original JC2 which was caned by the reviewers cos AD797 was the wrong choice for one of the applications. In the other application, there is little difference but this is cos the rest of the circuit is poor.
Both AD797 & 5532/4 would require extensive improvement to decoupling, earthing & layout in JC2 Mk1 to show their best.
______________
On the subject of -300dB stuff being audible, it is likely that the real reasons for an audible change are much more gross and we are looking at the wrong thing.
eg Poor decoupling, earthing & layout results not only in worse distortion but also RFI, EMI and hard to pinpoint instability (hard cos stability changes when you connect something to look at it). You can hear this on Blind Listening Tests bla bla
It may be JC's love for discrete FETs instead of OPAs is cos he hasn't quite figured out the importance of recommendations in datasheets and his decoupling/earthing/layout stuff is lacking for many good OPAs.
Poor choice of device for application is another important detail which is easily audible under certain conditions.
JC2 Mk2 illustrates the importance of
- looking at what needs to be done .. eg the source etc .. rather than Golden Pinnae myth
- Measuring the complete device under the working conditions and maybe a little more ... to check that your 'calculations' are valid.
There are faults/differences which ARE detected by Blind Listening Tests bla bla and faults/differences which miraculously disappear when you turn out the lights so the Golden Pinnae can't see the price tag or what they are listening too.
Which faults/differences are you going to concentrate on?
Tick, it was JC who told us the reviewers caned JC2 Mk1. You'll have to ask him which ones they were.
JC was using it as an example to dis AD797 when it was his poor choice of device, poor circuit and poor decoupling, earthing & layout that were almost certainly responsible.
At least it shows that not all Golden Pinnae reviewers are deaf
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Sounds reasonable ... the scary thing is, as the sound of a system gets better these influences become more and more audibly detectable - hence the madness in the "industry" ...
Yes, we just need some giant of a man, or company, to come forward and explain all of this in everyday, fully comprehensible language -- any takers ...?
Frank
Thanks Tick, for speaking up. Yes, the JC-3 (initially called the jc2 phono) has an A rating in the American mags: 'The Absolute Sound' and 'Stereophile' and I DID NOT use the AD797 in the final version. It got 'phono preamp of the year' in at least one of the publications.
This ranting about this product is hilarious. '-)
I didn't criticize the JC-3, I criticized the Parasound 2200 MK1 that included an AD712 in the input. The 2200 MK2 did not include this AD712, and it was successful. This all happened about 20 years ago. Scott never forgave me for removing the chip from the front end of the amp, but it was necessary to make it sound its best.
This ranting about this product is hilarious. '-)
I didn't criticize the JC-3, I criticized the Parasound 2200 MK1 that included an AD712 in the input. The 2200 MK2 did not include this AD712, and it was successful. This all happened about 20 years ago. Scott never forgave me for removing the chip from the front end of the amp, but it was necessary to make it sound its best.
Tick, I'm certain of it. There are several true gurus (I'm only a pseudo guru
) here that agree with me. Those who have spoken up certainly seem to do so.I'm waiting for JC to explain his reasons for his choice of AD797 for JC2 Mk1 and also ignoring the datasheet recommendations.
Several people have posted links that explain important points in detail, eg the TI/NS article on RIAA noise. The AD797 datasheet is worth reading and comparing against JC2 Mk1 schematic too.
If you have questions, there are many here who will be willing to help you understand the important issues.
Have you got a scope? Can you build a simple AD797 circuit? Much of this is Electronics 101 but its easier to see for yourself.
Why yes I have a scope. But rather than waste any more of my life on different versions of low bias opamps, I much prefer listening to my home built version of the Blowtorch, Borbely's all Fet high bias circuits, ( each of the 2 discrete all jfet/fet stages of the MC phono used heatsinked Hitachi 2sk216/2SJ79 at 80 ma to drive low impedance feedback and equalization components) through Pass and Borbely class A power amps on full range electro stats with subs. You can see a commercial version of the Borbely phono at the PBN Audio site. http://www.pbnaudio.com/audio-components/audio-preamps/olympia-p
A simpler, less expensive all jfet discrete version of the Borbely phono is the Liberty audio phono stage which Stereophile found to have the least RIAA error yet measured and a very low noise floor...
http://libertyaudio.com/accolades
A simpler, less expensive all jfet discrete version of the Borbely phono is the Liberty audio phono stage which Stereophile found to have the least RIAA error yet measured and a very low noise floor...
http://libertyaudio.com/accolades
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If so, there's no need to bother your head about the shortcomings of JC2 Mk1
... or if Blowtorch sounds worse than evil 4558 bla bla .. You can agonise, instead, over whether your cables etc were really hand carved from solid Unobtainium by virgins
Would like to see something a little more definitive.
When Bruno Putzeys did his cable measurements some time back, among the cables I sent him was some made using RG-174 coax which has a copper clad steel center conductor.
Seems to me that if just being in close proximity to steel is bad, then one of the conductors actually being made of steel should be something of an absolute worst case.
Yet the RG-174 cable showed no signs of distortion above the residual of the Audio Precision System 2 Cascade that Bruno used to make the measurements.
se
why the hell would he want Wilson XLF's? that says a lot actually, very expensive, but ultimately a waste of nice drivers. I can think of many better uses for money like that.
actually I thought he was pretty reasonable, its you that started beating your chest about your audio setup, like it somehow bends the laws of physics.
Borbely is a legend btw, i'm not speaking ill if any of the designers of the gear you mentioned; but the way you listed it out was un-called-for and the AD797 used correctly is a masterpiece of its own.
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