John Curl's Blowtorch preamplifier part II

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billshurv

billshurv

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Derfnofred said:
Freezer.

I enjoy photo books, not so much for grandeur inasmuch as composition, light play, etc. And we don't do photography or DiyAudio to really topple the best of the best, but for the inherent joy, no? :)
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Well with Audio you know you could build an amplifier that is close to SOTA for not much money. With photography there are shots that you just know you couldn't equal.

In my case I lack the OCD required to turn up at the same spot day after day to get the perfect image. I channel mine elsewhere :p
 
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DPH

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Joined 2008
If we're being equally logical, you can buy a SOTA amplifier for not too much money, too. Several of John Curl's own less expensive offerings would certainly fit that category. Saves on the complexities of building something that is subject to the insults and vagaries of life. A built amplifier, SOTA or no, sounds much better than a transformer, a capacitor bank and a handful of unpopulated PCB's. :) And if we're going for pure audio optimization, speakers and room should get the bulk of our effort, not minutia of this or that amp/DAC. (Phono/preamp probably are worth co-optimizing)

Agree there are photos that I'll never equal, but, then again, I have photos no one else will take. And they're wonderful in their own right (happy to be in the right place at the right time), even if I've made pennies on the dollar of my camera/lenses selling the random print to a friend.

I guess my value in both is the joy of creating something with my hands and my mind (even if I'm leveraging HEAVILY off others). I appreciate others are here for other reasons, whether they're financially invested or not, but that *seems* predominant motivation here on DIYAudio.
 
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arnyk

arnyk

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Derfnofred said:
Chris, other than high-quality line-level transformers tending to be expensive, what is the overarching exception many are taking?
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I have a few pieces of legacy hardware with both transformer balanced and active balanced outputs. The two sets of outputs have level and frequency response differences that are not fatal but might be audible.

Add in the usual effects of prejudice and and the lack of reliable testing mthodologies and its easy to see why transformer coupled outputs get a bad rap in many circles.

The actual performance is often audibly just fine, but YMMV.
 
W

Waly

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john curl said:
My cheap stuff does not sound as good as my expensive designs. They are passable, not near perfect.
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Mr. Curl, have you ever designed a piece of audio crap, that is, an absolute failure from a sound and/or engineering perspective? You mentioned once something that had an eight legs monster inside, quickly spotted by the audio review chimps, other such?
 
john curl

john curl

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I have never designed an awful audio product, BUT I have designed amps (for example) that measured great, yet were sincerely disappointing to independent listeners. In two cases with power amps, I had to completely go through the amp and change it significantly. Once, I removed an IC. Another time, I changed the bypass caps, feedback resistor and a number of other things, and made a very successful power amp from it. We even bought amps from Parasound and modified them, for ourselves and other enthusiasts. The standard measurements would not show any significant difference. That is the dilemma.
 
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K

KBK

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Joined 2003
COP between 20 and 80.

One year long third party independent test is now completed on a 1 megawatt power plant.

Certain members can kiss my ***, over all the undeserved abuse I've been given on this subject, over the years.

https://animpossibleinvention.com/2...nt-one-year-1-megawatt-e-cat-trial-completed/

To be clear, the report from the one-year trial, which has been controlled by a major independent third party certification institute, will be released only in about a month, and until then no official information is provided on the test result. However, multiple sources have told me that the test has been successful.

Earlier, some sources having visited the test plant told me that the COP, Coefficient of Performance, i.e. the ratio between output power and input power for control, was in the range 20—80, meaning that the heat plant was consuming 12—50 kW while producing 1 MW—the average consumption of about 300 Western households, including electricity, space heating, water heating and air conditioning.

I have also been told that the total amount of fuel—mostly harmless elements such as lithium, hydrogen and nickel, according to Andrea Rossi’s granted patent on the technology—was in the range of tenths of grams. And supposedly the charge has never been changed during the year. On the other hand, after one year’s run, the reactors are now being recharged for further operation.

All this might be confirmed by the third party institute, that has been controlling the heat plant 24/7 with video cameras.
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The next domino to fall... is ...what about the rest of the other claims on other similar subjects and devices?

Time to revisit.. and... scientifically speaking, grow the hell up. Welcome to the new world and it's new gold rush.

And don't be shy with those class A power amps! It's no longer the energy as an issue.
 
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dvv

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Joined 2004
john curl said:
I have never designed an awful audio product, BUT I have designed amps (for example) that measured great, yet were sincerely disappointing to independent listeners. In two cases with power amps, I had to completely go through the amp and change it significantly. Once, I removed an IC. Another time, I changed the bypass caps, feedback resistor and a number of other things, and made a very successful power amp from it. We even bought amps from Parasound and modified them, for ourselves and other enthusiasts. The standard measurements would not show any significant difference. That is the dilemma.
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Only to some, John, to people like yourself, myself and a few others that is an accepted fact of life. Desigimg an amp which is perfectly functional in electrical terms is only an introduction to making it sound right. Of all the amps I designed for myself, only one worked just right from the bat, and I realize that was a once in a lifetime lucky break, like winning the lottery.

My own discovery of how something can measure about the same but sound differently was when I stumbled on Dale resistors. Swapping standard 1% metal film resistors for Dale at the input and the NFB line really opened my ears and eyes. Heck of a difference, if you ask me. After that, of course, it all became easier as Dale resistors became my standard in critical places.
 
D

dvv

Member
Joined 2004
True, at least in my case. For a while, I thought it was a fluke, but an event of two years ago brought me back to the right track.

I was refresheing (changing old for new electrolytics) my old H/K 6550 integrated amp, most fortunately using exactly the same electrolytics purchased as spare parts from H/K because I wanted a straight refresh, no experiments. BTW, these electrolytics are some Korean brand I have never heard of. Then, on the spur of the moment, I decided to take out the volume pot, which I consider to be a crap quality product there only because it was cheap and ecause that is my standard gripe with H/K mass produced products in general. Anyway, I happened to have the exact same value of ALPS Blue pot, which I then slid in.

I have been surprised a few times in life, but never as then. All of a sudden, I had all the depth and sound stage fine detail I never had before from that unit, and in the amount I would never have thought possible after changing only one component. The little amp (50/70W into 8/4 Ohms) came alive as I didn't know it was even capable of. It cleanly beat its biggest brother (H/K 680, top of the line model in 1998) which has the ALPS Blue pot installed as standard equipment. And worse, it was now producing the kind of sound I would never expect from any integrated amp in its price class.

I guess the lesson is that you should at least try tweaking a standard product, it may have hidden talents.
 
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D

DPH

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Joined 2008
zapnspark said:
Sorry KBK. Overunity is still nonsense.

Andrea Rossi?s One-year 1 megawatt E-Cat trial completed - The Skeptics Society Forum

Cheers.

ZAP
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scott wurcer said:
I like the part where this guy was already a convicted felon in the 70's for energy scams. KBK keep your pants on.
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While I agree with "where there's smoke, there's fire", I'll wait for the deafening silence of non-reproducibility. This DEFINITELY fits under the realm of one of Sagan's best known quotes, which KBK so kindly reminds us of in every one of his (her?) posts.
 
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