John Curl's Blowtorch preamplifier part II

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Not at all, it's actually a great film former. One of its virtues (besides superb dielectric properties and easy metallization) is high tensile strength and low elongation, so a cap can be wound really, really tight. Something like Topas 6013 (the film grade) would work great.

The issue is the capital cost of setting up a new biax film line for a low volume and diminishing market.
 
This appears to be 'quibbling' about caps. SY is technically right, but PMA is 'practically' right. Sometimes names may be 'incorrectly' put on a part, but we still know what they mean.
For example, I have many hundreds, even thousands of the same type cap (Siemens) that were pictured. We used to buy them from surplus outlets. However, I don't think they are made anymore. They are my choice for anything less than 0.02uF polystyrene. They are VERY delicate, both physically and chemically, but they sound GREAT!
However, I also have many hundreds of MIAL caps. They LOOK better, but they suffer exactly what Richard Marsh talked about. They virtually SING when bonked.
 
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I use a full Relcap film and foil crossover in my speaker. Polystyrene only with the tweeters, and the PPFXS tin film and foil for the midrange with MIT RTX 0.33/600v polystryrene and 0.01 bypasses on each cap. They are selected with a calibrated meter and matched to less than 1% when parralled of the total uf value required and between channels. It's expensive, takes a lot of room to hold them mechanically correctly, yet in a good system ( full range electrostatics, Blowtorch clone, Borbely all fet power amp) are indispensible in getting the highest resolution.

Richard's work in bringing these capacitors to the audio market place (for which he now gets no royalties) are as important as the best electronics designs are . Too bad krglee you haven't heard them, yet criticize my evaluation of them based on your beliefs rather than experience. For 20 years now I have heard them, often replacing Solen metalized films, and judge them as an indispensable part of a reference system. Yes there are other well regarded caps Vcap , Mundorf's, what ever the current Inficap series are, which are preferred by others.... Like good wine or whiskey not everyone's first choice is the same, but Relcaps/Multicaps have for 2 decades of electronics evolution in my system allowed improvements or disappointments to be more readily heard better than any other cap I've used (and I haven't heard or evaluated them all). They are consistently top notch performers especially in crossovers
 
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More on caps - history

FYI -- many cap makers to the audiophile have taken what they could from RELiable Cap designs (like different foil materials) but one they have never duplicated is the multi sectioned/parallel cap feature. The reason is two fold -- it was patented and it required a custom built ($$$) cap making machine.

The result is extreamly low Ls and esr. The result being that self-resonance freq is pushed higher. This wasnt really for audio but had wider appeal. I think one can appreciate that there are many cap companies with many engineers over many years (100+) trying to make a better cap. in order to get a patent is thus very hard now as every possible cap idea has been patented or tried. This concept came about when I was working on very high voltage (100KV) discharge capacitor banks which needed low series L for fast energy transfer to the experiment (physics exper). The name "MultiCap" came from Bruce Brisson of MIT (cables) and he owns the trade name which is licensed exclusively to REL. Bruce paid me to get the concepts developed to become realized and marketable to audio. Moving on, I have no further interests nor royalty income from the patent as it has now expired. But because the special cap making machine has never been duplicated by others, it is still a unique part and with all the material science and manufacturing know-how that REL has, the combo has been a large step forward in film cap development.
---RNM
 
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No, Rel Caps are not good for guitar amps, necessarily. More DA is better for guitar amps I'm pretty sure.
John, my questions were ironic.
I don't think it is a good idea to encourage young DIYers to consider audio electronic like some kind of "cooking" where components have a "taste" or a sound.
They have characteristics we can measure, and they feat or not our requirements at the exact place in a schematic where we consider to use one of them.
In an other place, we will have different requirements, so different choice, and overpriced "audiophile" magic components are just "Snake Oil".
About caps, better to speak about their serial resistance, serial inductance, tolerance, distortion, noise, resonance etc... and provide comparative measurements.

I know so many "audiophiles", with poorly designed loudspeakers filters, using some "audiophile capacitors" with a resultant impedance curve looking like a mountain, between 5 and > 100 Ohms. And loudspeakers not properly aligned with a bad group delay as a result. They talk about their capacitor sound ! Is-it serious ?
 
Esperado, I am always serious about caps and their differences. I have also worked for musical equipment manufacturers, so I have some idea what works and what doesnt. A high DA cap may well be the best for many electronic instrument amps. Standard hi fi amps, especially preamps, do not sound right with solid body musical instruments. PA is different, and hi end hi fi is very difficult to get right with just about any coupling cap.
 
Too bad krglee you haven't heard them, yet criticize my evaluation of them based on your beliefs rather than experience.
Tick, I haven't criticized your evaluation of Relcaps. But doing Blind Listening Tests for nearly 2 decades gives you a certain mind set. I've tested some of the best ears in the business and am actually in awe of certain ears.

Sadly, what also comes out is that many professed Golden Pinnae are deaf.

My advice about syringing ears is in no way cynical as even the best ears need syringing every now & then. Some of the things which a carefully conducted test will pick up are quite surprising ... and often not what the Golden Pinnae brigade deem important.

What I did suggest is a possible explanation for your perceived 'improvements'. If Relcaps aren't microphonic, I'll have to try a different explanation. I haven't heard or used them so must take what people say on trust.

But I do have a 'practical' view of Golden Pinnae stuff.

I've no objection to Golden Pinnae stuff in expensive gear ... provided it is at least as good as what I consider appropriate and have tested to be so.

In speakers, (one of my specialties) I'm perfectly happy if you use certain 'hand carved by virgins' capacitors as long as I don't have to pay for them in my present impoverished state.

But in some applications like microphones (my other specialty), certain Golden Pinnae stuff has BIG cons.

In a very low noise high Z circuit like the preamp for a capacitor capsule, SIZE is an important factor. The large size of certain Golden Pinnae components make them excellent receivers of RFI & other EMI. This is not Golden Pinnae or even Double Blind Listening Test stuff but easily observed and heard in naive mike mods.

Again, I've never seen a Relcap suitable for this application so I can't comment. It may be that if I did try one, I might put it on an equal footing to my NPO/COG ceramics.

But I did post what I think is the ideal 1G resistor. Sadly this is now Unobtainium.
 
years ago, I had a power amp I wanted to sell in hong kong. It got a listen by the top high-end retailer there. he asked the msrp. $4500 USD. He said that was too low and his clients would not take it seriously until it was $40K or more. And, then it didnt look good enough to be sold for $40K. His clients only want the best and they do not come in to audition the gear. They depend on the store owner to do that. If the store owner knows of something better that has come along, he calls the customers and they have it sent to the customers home by currior and set up for him.

Many years ago, a Saudi civil engineer was having a 'villa' built for him as a prize for helping the usa company get the job. this civil engineer ownd sky scrapers in Manhatten and diamond stores for the ultra wealthy! His driver would not even take us to the engineers diamond store in S.Arabia as we didnt look wealthy in dress nor manner. Anyway, when asked which phono cartidge did he want - this or that one -- he just said.... which is the best? And, not to ask him such questions again. he only wanted the best.

That is where the real High-End is and has been for a long time. What we, the 99 percenters, think is expensive, isnt by rich and especially wealthy people. This is the customer that John's dealers has dealt with. So complain all you want about cost and expensive looks and over-the-top designs... it isnt being developed and sold for a 99 percenter.

I get demands to make the product more pretty. I say back, that we've done our best to make it sound as good as it can possibly be done. To make it pretty would degrade sound quality, notably so. Thus, no shiny crow bits to charm those who expect that aspect. Shiny bits are bad for field development....
 
Esperado, I am always serious about caps and their differences. I have also worked for musical equipment manufacturers
I was not talking about musical instruments or guitar amps ( They are some kind of cooking, by the way) and i hope, indeed, you are serious.
My remark was from a general point of view.
A scientific approach of electronic instead of a pseudo artistic one.
I hope you undersand why i was shocked by your sentence "they sound GREAT", and why i asked if electrons have some musical taste.
 
I'm perfectly happy if you use certain 'hand carved by virgins' capacitors as long as I don't have to pay for them in my present impoverished state.
I, too, would never pay both those caps and those virgins, for both technical and moral reasons.
And agree with all what you said in your post, specialty with blind listening.

I remember a blind test i made, long years ago, in my recording studio, with other sound engineers, to try to evaluate the quality of the ATRAC algorithm. Comparing instant ( synchronized ) an original digital mix with an ATRAC copy of it.
The result was ATRAC was mainly preferred to the original :)
 
I was not talking about musical instruments or guitar amps ( They are some kind of cooking, by the way) and i hope, indeed, you are serious.
My remark was from a general point of view.
A scientific approach of electronic instead of a pseudo artistic one.
I hope you undersand why i was shocked by your sentence "they sound GREAT", and why i asked if electrons have some musical taste.

This sort of line of questioning has come along and been dealt with hundreds of times.

The facts of the matter, are that we use our ears to hear things. And that the ear is not modeled to perfection, or is it easily understood how it works.

Add to it that we have, in our ear/brain system, an almost full analogy to a 3d waveform analyzing temporal and level based transient multiband system. All done in real time. In some ways... it makes a FFT analysis system look like a joke. Some of us can use it better than others can. The brain is plastic, and it can learn. Thus hearing is not static, it can grow into a situation where it becomes more capable. Learning, ie plastic brain, is a reality that engineers have to understand, as if they did not, they'd never have been able to learn to walk or understand these words on a page, how to drive a car, or use the internet or their stereo. Audiophiles exist and grow into better systems because of the simple fact that they LEARN, over time, with their plastic brains... how to hear better. Same for designers of audio, in both hearing and design of gear and testing systems/parameters/regimens.

Suffice it to say, a trained set of ears can hear better than most hardware can analyze. The problem is the brain that is tied to the given set of ears.

The problem with FFT and other methods of analysis, is the brain and mind that designed the hardware and the tests involved and how much they know about how we hear, and if they can understand how to devise proper tests that can show anything that is beyond basic in function.

For example, that linear weighted and designed testing regimens are so basic that they have great difficulty in showing what the ear so plainly hears. In simple unemotionally driven logic, this then illustrates a 'fail' of the design of the electronics testing regimen and it's orientation. That aspect, like anything else, is only as good as it's depth of knowledge.

With the right brain attached, in general, mind(brain)/ear trumps hardware. In some ways, the right hardware and software, with the right brain/mind attached, said hardware trumps ear/brain.

Each has their place, but this is about pleasing the ear/mind/emotions, so it owns 50% of the analysis chain, at the minimum, whether a given engineer likes it --or not.

it's not about ignoring logic, it's about realizing the simple fact that neither chain of analysis (ear/brain vs hardware) or logic is even remotely complete in effect, design, or orientation.

Now if we could only staple this to the forehead of everyone who enters this thread or these sorts of discussions, things (the discussion itself, regarding ignorance) would work considerably better.
 
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BTW, there is no such thing as a physical law, as your tag line suggests.

Any physicist worth their paper..understands implicitly that all is theory and subject to change.

Engineers are specifically taught 'laws' as they are to make gear/devices and commit to actions that create objects or similar connected tasks.

Physicists are taught differently, if they are correctly taught.

Exploration is about using the prior theory as a guide, nothing more. All theory is subject to change.

There is, for example NO law of thermodynamics. There is, though, a THEORY of thermodynamics.

The word 'law' has no place in science, whatsoever.

How many times do we have to go through this thing about not placing human contrivances as grouped norms of social conduct/contract (law), as injected into physics?
 
Define law as something you can verify each time by experiences.
V=RI.
I talked about laws because that's the way we name the Ohm's theory.. And this little formula helps more than trying blind resistances values until you get the expected current. Then publish than 1K resistance sound better than 2.2K !
Yes there is physical laws, even if we do not know all about them. But we improve our knowledge.
Theory of thermodynamics (if you prefer) is the only efficient tool we have to design machines able to send a robot on Mars.They are not designed by "feelings".

I don't agree that our ears are better than measurements instruments. Instruments are objective, and reliable. And you can see things that you don't even heard. (Yes we can hear things that we don't know how to measure)
Our feelings vary with time, humor, culture, on what we focus our attention, and even with what we dream to get. Our musical memory is nothing we can rely on.

The only problem with measurements, on my point of view, is to know what and how to measure and what kind of effects the results of measurements we see (levels, distortions, noise, bandwidth etc.) produce in our feelings.

As a sound engineer, i used my feelings (and culture) to chose my equipments, record and mix tunes, as an electronic designer, i prefer to use calculations (and experience). I use my ears , long time after, to correlate and validate the previous work. As an electronic engineer, in the research and development office i was working in, my boss preferred that i read data sheet and measure several same components before to validate orders for thousand of them.
Of course, we used to spend a lot of time to listen to our prototypes and parts, to try to understand better how and why.
 
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