John Curl's Blowtorch preamplifier part II

[syn08]

Originally Posted by Magura

Well, this particular Kleemann has the world speed record for sedans, but counting out that little detail, you're 100% right.

Never heard of Kleeman, but I've seen a Maybach 62S at the Toronto Auto Show and it's stunning. Costs 0.5M, a true auto Blowtorch, but worth every penny (if you can aford it ).

[pooge]

And...Stage 5.

[GK]

Originally Posted by syn08

John,

Since my favorite icon was removed from the smilies set.

Ha ha. I wonder why they did that?

[john curl]

Anatech, please understand that I did use 2 uH output coils for decades, from 1970-1990, fully understanding the NEED of the 2uH coil at my output.
Do you remember that I was one of the first designers of the complementary differential transistor input stage and most probably, the very first designer of the complementary differential jfet input stage? I also designed with complementary jfet input stages as well over 37 years ago. What is the most popular design today, Doug Self's design? Bob Cordell's? Well, I fit in there, somewhere, even though I only helped to introduce the comp-diff bipolar or fet input stage. Some people find it valuable, even today.
Actually, the use of the output coil is more a function of feedback and circuit stability, not anybodies 'popular' topology. For highest fidelity, it is better to not have a coil than to use one, so long as stability under difficult loads can be maintained.

[brianco]

Originally Posted by Magura

Don't step in it


Magura


BTW, the offer on carbon is still on John.

JC.

I too have reasonably extensive experience with thye use of carbon in audio construction. I really would take Magura's offer seriously and accept. It will not take very much time - or effort - to evaluate it's potential. (Re read your signature)

[john curl]

I'm sorry guys, I have no idea what you are talking about. Carbon? Graphite, diamonds, carbon fibre, graphene? What?

[GK]

Originally Posted by john curl

In Calif. because of smog, we are very much restricted in auto modification.

There are ways around some of those laws........

http://www.ronpatrickstuff.com/

[ostripper]

By JC - It is complete foolishness to use a 2 uH output coil, of any kind and design, unless you are interested in applying more negative feedback.

Besides the fact that you said one should never use MORE than a 2 uH coil , I see inconsistencies in your opinion(s).

I did scope a DIY amp (my amp) with a piezo speaker array , saw more ringing w/ sqaurewaves (200 watts synthesizer OP) on a scope. This did not destabilize the amp , but the coil partially corrected this. On the stupid commercial chip amp , which just survived 15 years of nightclub duty , I also see the 2uH coil (attachment).

I do not take the "chip amp"(stk-4050V) seriously , it can not hold it's own against modern discretes , but the coil has given it decades of "life" ,even bridged into 4R.

Actually, the use of the output coil is more a function of feedback and circuit stability, not anybodies 'popular' topology. For highest fidelity, it is better to not have a coil than to use one, so long as stability under difficult loads can be maintained.

Yes , myself and others have run without the coil , it falls into the same "leap of faith" category as running without overcurrent protection. We have amps that will do it , but the circuit might be called upon to drive a load like this ( the piezo array or electrostatics).

On my new triple , I noticed not much of anything with the capacitive load , but , like a "thick old man" , still used a coil. Using an inductance meter on the speaker cable, I saw 1-2 uH to start with , so maybe that is why I could run without the coil. ??
OS

[john curl]

Ostripper, you have now shown your own colors. I tried to be polite about using a 2uH coil. Sometimes people use them, I used to, but they are audible with the best equipment. To quibble with me, over my statement is just petty criticism, in an attempt to try to find something wrong with my general comments.

[Wavebourn]

Originally Posted by syn08

Never heard of Kleeman, but I've seen a Maybach 62S at the Toronto Auto Show and it's stunning. Costs 0.5M, a true auto Blowtorch, but worth every penny (if you can aford it ).

I was drooling looking at Brabus M-470 in 1999. So what? In 2005 I bought Nissan Armada that outperformed it in terms of specs significant to me, and I paid for it many times less. Armada worth more than every penny, in comparison with that Blowtorch made from a stock Mercedes that was greatly overpriced, right for "NO COMPROMISE" guys.

The point is, John is wrong regarding myself as a competitor. I would never ever compete for NO COMPROMISE customers; they are spoiled and demanding, and don't know what they really want. I prefer professionals who knows what for and which gear they are buying. They don't need advertisements on a shiny paper; you may regard absence of advertising on a shiny paper as a compromise to cut costs down.