John Curl's Blowtorch preamplifier

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scott wurcer said:


It certainly seems to amuse some, even some who can't participate. Not that they would want to.

You’re right, but we can’t expect that everybody is willing to put their head on the block.
 

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This is not useful, the tests were done about 25 years ago. We needed the best op amp available at the time for the job. Please don't 'bait' me and my efforts. They will be known soon enough. Mitch Cotter say hi, and I told him about you and Sequerra. He has provided the 'key' to the whole problem. If I were you, I would stay civil, which you are not, now.
 
john curl said:
This is not useful, the tests were done about 25 years ago. We needed the best op amp available at the time for the job. Please don't 'bait' me and my efforts. They will be known soon enough. Mitch Cotter say hi, and I told him about you and Sequerra. He has provided the 'key' to the whole problem. If I were you, I would stay civil, which you are not, now.

I talked with Mitch twice last week trying to get him some samples, and look back I honestly thought this was a coincidence. My sig says it all, those JW's were pretty smart. :D
 
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Gee, it seems like the same old personalities are still fighting.

Hey John, I think you are too sensitive to comments in general. You may be reading malice where there is none. This makes you come off bitter at times. I'll bet you could do without the stress.

I think that some of your ideas are accepted just fine while others may not be. So? It's not like you're rejected as a human being. All you need to do is explain some of your beliefs, rather than declare them as untouchable fact. Considered questioning and debate should be welcome opportunities to understand a topic better from different angles.

One clash of ideals seems to be the belief that what one hears can not be reconciled with what can be measured. While that may be true in some small areas, it certainly isn't overall. It seems more like a fight between those who can access test equipment and those who can't. Those who can't like to justify that they don't need anything other than their ears. What I'm hearing from people who do have access to test equipment is that they can and do use that - and their ears.

You know, it seems foolish to ignore tools that help to get to the answers or goals. I can tell you from personal experience (and it's no less valid than our golden ears contingent) that the more equipment I got to use, the more I could explain what I was hearing. More importantly, I could quantify and reduce in meaningful ways the bad things I could hear. Can I do this without listening? Probably not, actually - no. My ears need a guide occasionally, and so do any advances I want to make through listening.

These things are not exclusive at all. I wonder how many off the golden ear crowd would change their tune if they suddenly had access to equipment, and the knowledge of it's use and limitations. The other question would be if their egos would ever permit them to admit this change of heart. ;)

-Chris
 
PMA said:
No. I gave up the circuit you mention.

PMA you said you gave up based on simulation?? There are no JFET models in any SPICE that will correctly predict at the -140dB level. Ask syn08, but I thought that fitting across regions by making only one or two derivatives continuous guarantees some higher order numerical "noise" i.e. the harmonic field of "grass".
 
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Hi Pavel,
Sounds interesting. Of course, it sounds familiar to many earlier designs but that does not mean it's a copy of anything. (comment for stinius here).

Do you plan to develop it yourself, or will you start a thread and discuss any part of it? If you do, we'll probably have to moderate for personal attacks rather tightly. That's not a warning, but more an attempt to keep things on track for you.

I do like your designs that I've seen before.

-Chris
 
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scott wurcer said:


PMA you said you gave up based on simulation?? There are no JFET models in any SPICE that will correctly predict at the -140dB level. Ask syn08, but I thought that fitting across regions by making only one or two derivatives continuous guarantees some higher order numerical "noise" i.e. the harmonic field of "grass".

Right

anatech said:
Hi Pavel,
Sounds interesting. Of course, it sounds familiar to many earlier designs but that does not mean it's a copy of anything. (comment for stinius here).
Do you plan to develop it yourself, or will you start a thread and discuss any part of it? If you do, we'll probably have to moderate for personal attacks rather tightly.

-Chris

Chris, you can call it whatever you like, it's a copy. (nothing new)
BTW: if he is starting a new thread, I see no reason why the thread shoud be moderated rather tightly.
 
anatech said:


One clash of ideals seems to be the belief that what one hears can not be reconciled with what can be measured. While that may be true in some small areas, it certainly isn't overall. It seems more like a fight between those who can access test equipment and those who can't. Those who can't like to justify that they don't need anything other than their ears. What I'm hearing from people who do have access to test equipment is that they can and do use that - and their ears.


-Chris

Chris,

I think that might be a slight over simplification. I still believe for most audio measurements one could DIY some incredible instrumentation. The philosophical differences run deeper than that. In fact there are those that believe those with the best instrumentation and knowledge of using it are less likely to produce a better audio product.
 
john curl said:
Soon, I am going to try two IC op amps and compare their 'subjective' sound to each other. These are the AD791 and the AD825. Anyone taking any bets? :devilr:

If SY referees the result would probably be random. Of course there is probably no common circuit in which to test both fairly.

BTW I treated Mr. Cotter as a respected customer and gave him almost an hour of my time and personally expedited his requests, please don't say I'm uncivil in asking for the results of this to have some continuity and make some overall sense.
 
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