John Curl's Blowtorch preamplifier part II

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Holy crap I was just talking about them with a client a couple of days ago, haven't actually heard them in ages. Some call them the headwaters of rap music, but I think that does them a disservice, especially considering the current examples of that genre.

Sort of gives PC two sides. Public Enemy maybe had the political vibe but most rap descended into the same old misogyny, abuse of women crap.
 
Mark Johnson

"On the other hand, I am confident that skilled engineers can build audio equipment whose sound quality and listening enjoyment does not change one microscopic iota when excellent diodes + optimized snubbbers are added / removed. {obvious example: put the PSU in its own chassis located 5 meters away from the main signal-handling chassis, and apply plentiful numbers of common mode chokes, RFI filters, and cascaded voltage regulators between incoming DC and analog signal PCBs}. "

There's a million ways to do that wrong. Doing it right isn't easy. There's a LOT of pitfalls.
 
There's a million ways to do that wrong. Doing it right isn't easy. There's a LOT of pitfalls.

Alo the more reason to take simple precautions like better diodes and snubbers, much cheaper, simpler, effective than cascading regulators, to get to the same place. Also PSRR of the powered circuit can tell us a lot about the benefit of PSU improvements.
 
Thanks guys for the tyre inputs. We could argue all day about whether wider tyres have real cornering advantages, but we can just drive on them to learn for ourselves, or rely perhaps on F1 race car measurements. Or perhaps, (gasp) rely on driver's testimonials! '-)

Well that's just silly. Drivers have all kinds of subjective impressions, and lots of drivers who "felt" fast lost races. Meanwhile the science can accurately predict tire performance vs geometry and chemistry, and solid engineering can predict how tire changes will interact with vehicle dynamics​. You should probably​ read some 1960s vintage books on the topic before offering an opinion.
 
Well that's just silly. Drivers have all kinds of subjective impressions, and lots of drivers who "felt" fast lost races. Meanwhile the science can accurately predict tire performance vs geometry and chemistry, and solid engineering can predict how tire changes will interact with vehicle dynamics​. You should probably​ read some 1960s vintage books on the topic before offering an opinion.

Up until fairly recently, relative to the 1960's, at racetracks car crews had to rely a lot on driver feedback as to how the car was handling on particular parts of the track, and they learned to a large extent by trial and error what fine tuning adjustments were likely to help improve performance.

Of course, now big time racing employs extensive metrology: http://www.qualitydigest.com/inside...scar-race-cars-through-better-metrology.html#
But in amateur racing, and for a long time in professional racing, driver feedback was very important for optimizing performance on different tracks.

Therefore, I don't think John's comments were all that silly or unreasonable.
 
Look Scott, I realize that you have never been interested in car performance, but many of us have been over the decades, and I had a thoughtful question on the subject.

You know, John, when I was in high school and first read equations about friction, I had the same thought except about brakes. If frictional force is proportional only to applied pressure and coefficient of friction, then why do high performance​ cars have larger brake disks and pads? The answer of course is temperature and how coefficient of friction of materials changes therewith.

So that is a question​I asked my high school physics teacher when I was a teenager. You are not a teenager and claim to be interested in science and cars. I am somewhat surprised that this is the first time you questioned tire width vs performance.
 
You are not a teenager and claim to be interested in science and cars. I am somewhat surprised that this is the first time you questioned tire width vs performance.

I don't know if you know it, but John is around 75 years old. The average life expectancy in the US is now around 78 years. As people get older, they may not remember everything they ever wondered about, or asked about, in high school. Don't know why that would seem surprising.
 
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Yes. Even today, car mfr - after all their modelling - still rely on additional input from real human drivers to make any final adjustments.

In JUne I will take a driving course, offered to me by Cadillac, for free. Three days to learn the high speed handling and best line around a road course etc etc etc. Mfr offered this to me and the hands-on course will be taught buy Pro drivers.

There is just soooo much you can experience and learn on paper. Then I will know its weakness and improve it.

Its the same process in audio... design and practical listening and iterate if necessary.


The road course is outside Las Vegas . Should be educational and fun.


THx-RNMarsh
 
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Yes. Even today, car mfr - after all their modelling - still rely on additional input from real human drivers to make any final adjustments.

In JUne I will take a driving course, offered to me by Cadillac, for free. Three days to learn the high speed handling and best line around a road course etc etc etc. Mfr offered this to me and the hands-on course will be taught buy Pro drivers.

There is just soooo much you can experience and learn on paper. Then I will know its weakness and improve it.

Its the same process in audio... design and practical listening and iterate if necessary.


The road course is outside Las Vegas . Should be educational and fun.


THx-RNMarsh

People have very different descriptions of the same feeling/experience. That applies to driving and audio... so experience trumps big time.
 
We could argue all day about whether wider tyres have real cornering advantages

Well that's just silly.

Up until fairly recently, relative to the 1960's, at racetracks car crews had to rely a lot on driver feedback as to how the car was handling on particular parts of the track, and they learned to a large extent by trial and error what fine tuning adjustments were likely to help improve performance.
Therefore, I don't think John's comments were all that silly or unreasonable.

I am very aware of how driver input helps teams fine tune overall vehicle performance. I am particularly reminded of Nikki Lauda's skill with car setup back in the day; he was very good at putting in some fast times early in qualifying, then spent laps practicing​ on full tanks so that he would have an advantage on the early laps and open a lead. None of which has anything to do with tire dimensions. There has never been a case that I am aware of where an auto racing team decided that they were faster with skinnier tires. So I stand by my assertion that John's question​ was a bit silly, especially if he claims to be interested in automotive performance.
 
In JUne I will take a driving course, offered to me by Cadillac, for free.
...
The road course is outside Las Vegas . Should be educational and fun.

THx-RNMarsh

Sounds great and I envy you, but don't pretend it's free. You already paid for it.

Now my brother is, among other things, an accredited automotive journalist. He regularly gets review cars to drive for a couple of weeks at a time, and when he and his wife went to Scotland a few years ago he called up BMW Canada and they gave him use if a Mini Cooper while he was in the UK (he also stayed in a castle with the owner of a well known the distillery whom he had met in another context, but that's a different story). Now BMW sent him to a high performance driving school which they operate, and in his case I think we can say it was free, though I am sure BMW expected some positive reviews, so maybe nothing in this world is free (he just didn't have to buy a car).
 
There has never been a case that I am aware of where an auto racing team decided that they were faster with skinnier tires. So I stand by my assertion that John's question​ was a bit silly, especially if he claims to be interested in automotive performance.

Okay. Was there ever a case were a team found they were faster with wider tires?
If so, then they may have tried even wider tires, and at some point they might have found that they tried tires that were too wide. In that case, wouldn't they then reasonably decide they would be faster with skinnier tires?
 
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