John Curl's Blowtorch preamplifier

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I think that I have found a secret impugner of my reputation. Anyone want to offer any evidence?
This is the point: I have worked diligently for decades to make better audio. I do it for a living, so it is easier for me to have tried more things than many here. I don't really 'cut-and-try' at random, but I listen to what has worked for others, as well as myself, and I don't deliberately push people away by telling them that something is 'impossible'.
The more we are educated by the 'system' the less we are inclined to accept 'new' information. Ever talk to your MD doctor about your favorite vitamin supplement? Same thing.
A few weeks ago, I accidently came across an input to TAN, a network that was popular, before the internet got going, bigtime. It was 13 years old! Yet, I was debating at the AES, EXACTLY the same stuff that I get, from Syn08, Cordell, et al exactly as I get here, today. I am apparently wasting my time, as Dimitri has already collected my inputs on the internet for the last 10 years, and put them up for anyone to read. I just don't have enough time left to waste my time, repeating myself. I 'may' have 10 more years, if that, given the state of my associates and their maladies, and I have come to realize that nobody is going to change the direction of this thread, except me.
 
It strikes me that many people do not appreciate that people such as John, Joe Pass and many others have absolutely no need to post here. It also strikes me that there are some people who make a point of being rather objectionable to virtually anything an expert has to say. Others raise petty quibbles and some are just downright objectionable!

The first group - those with deep experience and knowledge which they give freely as far as they can (usually relying on the audio industry as the field in which they make their living) - are the givers of this world.

Those who set out simply to attempt to knock down the hard earned knowledge which is given - whilst usually having only a little knowledge garnished with half baked ideas - are not even the takers of this world...they are just knockers-down - with little to contribute.

Others who benefit from the site may well risk loosing the 'givers' because of the social irresponsibility of a very small section of members.
 
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scott wurcer said:


I would love to see if this circuit is more suitable for discrete applications. I have to be careful and not make any lawyers unhappy so in this case I have to stick with simply pointing out what's there already (and in the public domain).

For those of us who have only a tenuous connection to IC design (when I was last close the masks were cut from Rubylith by hand, its changed a lot since then) how good is the transistor matching? I know there are trimming techniques (lasers and fuses) but I understand you have ways of holding devices to pretty close tolerances by design. That would make some tricks possible that are hard for discrete devices. At the same time with discrete parts its possible to get better isolation (thermal and electrical) than possible on a substrate. A little insight into those differences may help us on the outside see whats needed to get those ideas working in discrete parts.
 
brianco said:
It strikes me that many people do not appreciate that people such as John, Joe Pass and many others have absolutely no need to post here. It also strikes me that there are some people who make a point of being rather objectionable to virtually anything an expert has to say. Others raise petty quibbles and some are just downright objectionable!

The first group - those with deep experience and knowledge which they give freely as far as they can (usually relying on the audio industry as the field in which they make their living) - are the givers of this world.

Those who set out simply to attempt to knock down the hard earned knowledge which is given - whilst usually having only a little knowledge garnished with half baked ideas - are not even the takers of this world...they are just knockers-down - with little to contribute.

Others who benefit from the site may well risk loosing the 'givers' because of the social irresponsibility of a very small section of members.


You forgot about one more group, that tries to position itself above everybody, judging judges, contributing absolutely no technical ideas in any discussion. :cool:
 
brianco said:
... Joe Pass ...
Now that was a good one! I think that Mr.Nelson":cool:"Pass can live well with that mix-up. :D
 

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1audio said:

how good is the transistor matching? I know there are trimming techniques (lasers and fuses) but I understand you have ways of holding devices to pretty close tolerances by design.

Demian, far and away the biggest factor is the ability to ratio, exactly, emitter areas on IC's. The uniformity on modern IC's is shocking to those used to discrete design. Six sigma offsets of <100uV are common. Area ratioing is limited by photo lithography which is driven by sub-micron CMOS. Make big bipolars on the same equipment and you get super matching for free. Of course you don't make bipolar masks on the very best, we are approaching (maybe over) $1,000,000 for a 12" mask set.

The multi-tanh circuit needs an exact emitter area ratio, 4 is pretty close, so I figured 5 discretes pulled off of a strip is worth an experiment. I don't know if the second circuit is any better. I have another that I am pretty sure does not use area ratioing and still achieves a flat gm region (no PIM:cannotbe: ), but this is unfiled IP that I can not share.
 
Wavebourn said:



You forgot about one more group, that tries to position itself above everybody, judging judges, contributing absolutely no technical ideas in any discussion. :cool:


That would include me of course!


KSTR said:
Now that was a good one! I think that Mr.Nelson":cool:"Pass can live well with that mix-up. :D

Now I am really embarrased! Apologies Nelson.


:blush:
 
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