John Curl's Blowtorch preamplifier part II

Status
Not open for further replies.
a summary needed?

What do you expect? Any input from those that are not of the "faith" is immediately discounted.
I think we should consider the genesis of the thread, which, if I understand it, was John giving us an opportunity to appreciate his design philosophies using the Blowtorch preamp as an example.

If someone (not me, as Mr. Natural tells Flakey Foont) were to perform a service, it would be to summarize that philosophy, giving references to specific posts, and then, as a secondary summary, the comments from others about them. We can omit the personal attacks, slurs, defensive responses, and other incendiary rhetoric along the way.

I think this could condense down what has been expressed to something fairly digestible. For example, I recall one post from JC that said, in essence, paralleled devices could be good, complementary devices could be good, devices in series not so good. JFETs preferred to bipolars (indeed, that bipolars could not deliver good noise performance). This is just an example.

Periodically it is reiterated that negative feedback is audible (local bad, global worse) and deleterious thus. This is controversial of course, and attempts to establish the premise almost immediately run afoul of the double-blind-testing conundrum. Listeners can hear it until they can't see it. Scientists see this as, patently, evidence of the nonexistence of anything that passes muster. Those who are certain of what they hear with sighted tests have to explain why under DBT their discriminatory faculties seem to fly the coop. Maybe there are such explanations, but they may take us out of the realm of science per se. This would not be unprecedented---not everything is about science. Or, of course, some will say we just don't do the right science yet. I'd like to find that this is true, as I am interested in new things, but to date even when wishing to hear certain purported effects (for instance the effect of line conditioners like the Tice Clock and allied gizmos) I've been unable to. Naturally, the simple explanation is that I have lousy discrimination.

Perhaps we need triple-blind testing, so that during the collection of data nobody knows, not even a computer (which doesn't "know" anything anyway) that the data will ever be construed as the results of testing. The listening warrior will be impeccable because he/she won't be doing anything but listening.

The tests then become, at some later date, something eventually released on my favorite label, Akashic Records.

We should remember that this is The Lounge.
 
anatech & audiolapdance
this is the way I write.Off my head.
...
so I post the posts I post

Write any way you want, but please note that most posts aren't one-liners. Write all you want, but only post every 10 mins 😉 ]

Otherwise, this causes

s

p


r



e





a






d





out, and the reader ends up having to zip through pages, instead of just posts, to absorb the discussion, information, hints and advice that's such a Gold Mine here (second to none!).

If you look around, you'll see that usually, that's not how we fly around here.
And that's why this place ROCKs!

Cheers,
Jeff
 
Last edited:
Write any way you want, but please note that most posts aren't one-liners. Write all you want, but only post every 10 mins 😉 ]

Otherwise, this causes

s

p


r



e





a






d





out, and the reader ends up having to zip through pages, instead of just posts, to absorb the discussion, information, hints and advice that's such a Gold Mine here (second to none!).

If you look around, you'll see that usually, that's not how we fly around here.
And,
that's why this place ROCKs!

Cheers,
Jeff
 
Part #1 ----Tice Clock....... I am one of those who believes someone hears what they say they hear, especially when a lot of people say the same thing about 'something'

So it was when people said they heard changes to the sound of their system, when the Tice clock was plugged into the wall outlet, that I tested a Tice clock.

Many audio designers and listeners use their ears to guide their designs and not only crack-pots. People like M.Hawksford, R.Greene, S.Linkwitz, W.Jung, and many others. So, I am inclined to believe them if they say they hear something.

So, when it came to the Tice closk and being the test equipment junky that I am.... I tested it. I did series tests and parallel tests at the Tice line cord plug with a network analyzer. To my surprise what correlated to listening was a weak notch in the audio frequency range in the middle spectrum. Taking the clock apart I discovered it was the transformer and C inside is what formed the weak notch filter. I made a similar filter using cores I had lying around. I could make a deliberate filter, deeper notch... and see how it measures and sounds.... It measured better than the clock's notch... deeper. I tried using various core materials for the filter,... And that filter was more noticeable to hear when listening to music

That lead to an ac line noise investigations and a new wideband filter design (and a patent for it).


THx-RNMarsh
 
Last edited:
I can say I have no appreciation for a fine bottle of wine, I wouldn't know it from some $5.00 bottle of wine. I have probably imbibed about as much alcohol in my life as some people can do in a day, never developed any taste for drinking, then again I still don't drink coffee or tea.
Last throw of the dice on this, sorry 😱 ... a special one is when the experience gets better as you go down the bottle, the very last sip is the best of all - all the tastes and sensations as you drink keep building, accumulate as you consume, the wine never becomes just something liquid to accompany the meal.

My wife and I chanced on such a red many decades ago - she had no interest in red wine before that, as a result of exposure to very poor quality plonk produced in NZ. Instant, full conversion occurred at that meal for her - you then keep chasing for that experience to occur again, without having to pay through the nose for it .... 😉 .
 
Where the conversation should be going, IMO, is working out how to really measure what constitutes genuine high end sound, rather than how to build more fiddly boxes - as Richard says, and like the red wine, once you experience the good stuff you realise that all the other stuff is way down in the pecking order, OK to fill in the gaps when you're not fussed - but not to be ever confused with the genuine, high quality article ...
 
Hi Brad,
I think you are onto something. A package that can be understood, then discussed and extensions made from there. Everyone has their own way of getting from point A to point B, so giving John the space without hecklers might really bring a breath of fresh air in the thread. How about a brand new shiny thread for this event? Let the science and art blend into a finished product.

I'm sure that Scott, yourself and others may have some intelligent exchanges with John in a relaxed atmosphere. The moderating team can support you all in this. Just say the word.

-Chris
 
Hi fas42,
Some of us use those fiddly boxes to stay on track, or to investigate an idea. I am afraid that you're stuck with screens and dials as much as you are with a good listening room and audio equipment. The two are inseparable on the trail to higher performance. Part of the art is knowing what you are looking at and what impact it may have. But, we each have our own process in getting there.

-Chris
 
anatech,
I think you just made a very astute comment there. It really takes a combination of art and science to end up with the end result we are all looking for. If you ignore the science when doing your art you usually end up with the same thing, the color brown. You just end up making a mess of it all, you truly do need to understand how to mix and match if you want to get to the rainbow and not end up with that brown mess.
 
Many audio designers and listeners use their ears to guide their designs and not only crack-pots. People like M.Hawksford, R.Greene, S.Linkwitz, W.Jung, and many others. So, I am inclined to believe them if they say they hear something.


THx-RNMarsh


isn't this sort of the same thing..... In my personal interest in art, music and science it is a blend of it all.... all the time.... no matter which one I am involved in fundamentally..... its all related in my approach and work. Of course we all have our own internal processes to figure things out. but I think it is in this art and science mix is where the desire (for me) to have the end result be elegant, efficient and balanced/symmetrical etc etc. Its just more beautiful work.

Maybe this is done unless JC has more he wanted to say/show/teach/explain.

It has been an interesting two years for me.....
especially some of the characters I've met here.


Sincerely,
Richard Marsh
 
Last edited:
Hi Richard,
Surely there are other interesting threads and folks around here even if John doesn't wish to summarize. I know you are a man of many interests, and even watching the wildlife around here can be interesting as heck!

I'm considering that it might be worthwhile to try this if the new thread is more heavily moderated so that the noise level is kept low so John's ideas aren't lost in the din of the never far away jungle. This would be for his overall design ideas - what he thinks is important. However John would wish things to go. It would be worth the work on our end I think, and hopefully be more rewarding for John.

-Chris
 
It really takes a combination of art and science to end up with the end result we are all looking for. If you ignore the science when doing your art you usually end up with the same thing, the color brown. You just end up making a mess of it all, you truly do need to understand how to mix and match if you want to get to the rainbow and not end up with that brown mess.
IME it requires art in audio at the moment to properly assess whether you have that "brown mess" or not - science is currently poor in doing a full, comprehensive assessment. Then one can decide whether to continue to use just art, or science only, or a combination of the two to advance "the art" - personally, I use science as a tool to give me answers, and ways to improve; if that fails I have no compunctions about falling back upon relying on art, if it gives me worthwhile results ...
 
It would be good to pause and remember every now and then some audio gear from yesteryears, which we consider to be good then, and still sound good today. Just surviving the 40+ year competetition is a feat unto itself, and even more so when one takes into account how those who made fared over this time.

I wonder how come my old Marantz 170DC power amp managed to sound so good then, in 1978 when it was introduced (mine was made on 24 March, 1978 according to a factory stamp inside), as was its bigger brother, 300DC, which was virtually identical, but with higher PSU rails and slightly more powerful versions of the same family of output devices. Yet, the 300DC never managed to sound as good as its smaller sibling. Not bad, but just not as good and relaxed.

I believe that's one example of a product made by someone who really knew his stuff, Nige told me he thinks it was Sid Smith heading the team, but that doesn't compute with other data which shows that Sid Smith left Marantz about 3 before its appearence. Not likelčy, although nmot impossible, that they kept it in some drawer for 3 years. BTW, that was the last of the "Designed in U.S.A manifactured in Japan" series. Also, arguably the last truly memorable model of that company, the next highly vakued models too another 10 years to appear (PM80 and its variants and offshoots).

What impresses me is that after 37 years, it still sounds better than most of the new models. It's more transparent, it has more ambience and it sounds relaxed, not an inkling of strain, even when pushed hard. True, when exchanging caps, I did beef it up some, threw out a dual concentric 12,000uf/56V Elna cap and installed discrete 2x22,000 uF/63V caps by BC Components, but this only amplified its virtues, brought them more into the light, so to speak, but hardly some revolution.
 
IME it requires art in audio at the moment to properly assess whether you have that "brown mess" or not - science is currently poor in doing a full, comprehensive assessment. Then one can decide whether to continue to use just art, or science only, or a combination of the two to advance "the art" - personally, I use science as a tool to give me answers, and ways to improve; if that fails I have no compunctions about falling back upon relying on art, if it gives me worthwhile results ...

In my view, to produce something truly good, one HAS to use both science and art. In the end, every audio device will be voiced by the designer's ears, and it's been said that listening was a natural process, but hearing was art.
 
Dejan, in the patent-sense of the word, I can agree with you. Good audio is state of the art and the culmination of progress in different sciences. However, it is and will remain engineering.

The idea that every audio device will be voiced by the designers ears is first of all untrue, because in the reality I experienced this is not the way products are developed. Given a set of specifications, engineers start out to work out a solution that confirms to the specs, including available budget. It is creative work, where many different elements have to be balanced. He can use existing art, of invent his own. This is the art part. Ears come in only later, when the job is done.

The reason this is so is because we can measure differences that are way beyond audible. Ears often are the wrong instrument to make progress.

If Beethoven had been an EE of comparable talent, he could still have designed the Marantz 9th at the end of his career.
 
I'm sure that Scott, yourself and others may have some intelligent exchanges with John in a relaxed atmosphere. The moderating team can support you all in this. Just say the word.

-Chris

Hey Chris, IIRC you were instrumental in setting up this thread here many moons ago (no Scott not 40 years ago - but close)? I always thought that it was done to keep the usual troublemakers in a singe place to make it easier to manage for you mod guys? 😀

Jan
 
Status
Not open for further replies.