John Curl's Blowtorch preamplifier part III

Status
Not open for further replies.
The challenge was up for many years.

//

Sure, i was answering to your "still" after Scott_Wurcer´s post.

But, before the Randi/Fremer event i suppose nobody had thought about the Randi challenge (at least i wouldn´t have thought that listening abilities would qualify ) and after it the challenge was suspended for some time and was restarted with altered rules.

Iirc other members of the JREF stuff weren´t happy with Randi´s handling of this affair, for good reasons i think.
 
Simply no, as no further negotations about the specifics were done. Randi "weaseled" out, which means from an objective point of view he was not acting in goog faith, used dubious statements as arguments and violated/changed the rules of the JREF challengs during the back and forth with Michael Fremer.

You mis-understand, I stated MY opinion of a potential flaw in such a test. Unless I'm mistaken you don't hesitate to do so yourself. I was present at a cable listening DBT (I'm sure the protocol would have failed your standards) where one of the cables made the amplifier oscillate when this was discovered later the participants (with vested interests of course) claimed that it did not matter (you can't hear 60MHz).
 
Member
Joined 2002
Paid Member
So the maximum power issue becomes what dynamic range is available on the recordings you are listening to.

In opera recordings, the soprano part requires easily 50dB for intelligibility purpose alone. Add 10dB for decay of the voice.

The musical content of classical music recordings needs a dynamic range of at least 60dB (bad recording)/ 90 dB (good recording).

What is each one’s room upper “permitted” SPL? (90dB C fast?)
What is the ambient noise level in one’s room? (35dB A slow?)
How many dBs deep into ambient noise can one discern music? (20dB?)
Use one of the links in post # 9771 for test, grab the SPL meter and check :)

George
 

Attachments

  • cl.png
    cl.png
    94.4 KB · Views: 187
You mis-understand, I stated MY opinion of a potential flaw in such a test.

Always possible that i mis-understand something...you could make it a bit easier for me though.

I´ve cited to what a i responded:
"Randi got poor advice in setting up his challenge. IIRC he left the door open for someone to choose pathological combinations of speaker/amp/cable where easily detected frequency response anomalies could occur."

It was my impression back then that Randi mainly acted without advice first and only quite late listened to advisers.
But at that point when he stopped the whole thing (what i called "weaseled out") Randi and Fremer were still only talking about the choice of cables anything else even more open for discussions/negotiations.

Unless I'm mistaken you don't hesitate to do so yourself. I was present at a cable listening DBT (I'm sure the protocol would have failed your standards) where one of the cables made the amplifier oscillate when this was discovered later the participants (with vested interests of course) claimed that it did not matter (you can't hear 60MHz).

And now it´s my impression that some kind of hostility is included "..you don´t hesitate to do so yourself" and "...failed your standards" that is imo uncalled for, but maybe i´m mis-understanding (again)......
 
And now it´s my impression that some kind of hostility is included "..you don´t hesitate to do so yourself" and "...failed your standards" that is imo uncalled for, but maybe i´m mis-understanding (again)......

Sorry no need for this, simply a test can be flawed in many ways not just the statistical protocol. I see too little discussion of the technical issues of actually putting a component into the rest of the system.
 
When the only tool you have is a hammer, all problems tend to look like nails.

When, in order to ensure a test is valid, an understanding of auditory perception & statistical methods, is required, then yes those issues are important.

Some here, have neither understanding nor interest in these aspects
Your dismissive post is uncalled for.

Yes, there can of course also be technical considerations in any test setup as Scott mentions
 
Sorry no need for this, simply a test can be flawed in many ways not just the statistical protocol. I see too little discussion of the technical issues of actually putting a component into the rest of the system.

No one here puts attention to technical facts and measurements accompanying the test. Instead, complaints to a protocol are expressed and technical information is overlooked.
 
Been a while since I measured that but it would be at least 4 bells. So add 4 zeros to the power requirements! Maybe even 5!


As long as we are being pedantic (who, me?) 4 bells would look like this
Unique Early Brass Horse Hames Shaft 4 Bells Set Sleigh Buggy Equestrian Leather - Tique Trader
or would be 2 hours into your shift. On the other hand, four Bells would be four bearded old Scotsmen. I think you were referring to Bels (a deciBel (dB) being one tenth of a Bel).
 
At least PMA is doing tests, they may not be what you or Jakob would do, they are involving the community here and many consider them to have some value. All either of you do is criticise, neither of you have actually done anything constructive here, personally I'm finding it very tiresome that you don't even attempt to do anything positive
 
Hi everybody. Happy Thanksgiving to all of us in the USA, and good vibes to everybody else! I am in no position to bicker about how I finally got acceptable digital sound. It took about $45,000 in equipment and a little extra (proprietary) magic. Still, it finally worked. CD's however still are marginal, of course.
I recommend that those who can get access to Dan's 'goop' to try it. I have not, but I know he is on the right track. This sort of thing that Dan and Jack does creates a 'shortcut' over even heavier investment in audio equipment, but you have to try it and trust your ears, not your 'common sense'.
 
Status
Not open for further replies.