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John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
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Old 19th February 2018, 03:29 PM   #121
john curl is offline john curl  United States
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Anatech, thanks for the advice, but I use a Marantz 10 tube tuner for my reference. I bought the Sony to listen to when I was repairing the Marantz a few years ago. I haven't really listened to the Sony since, even though I made a few improvements. It is a very advanced digital design FM tuner, but unfortunately it still sounds 'digital' when I listen to it. The Sony's measured performance is impressive I am pretty sure. The point is: While Sony engineers will sink millions into developing their own RF chips, they just throw some analog output on, without regard to the cap quality, to finish the product. This is normal, because good caps are large and expensive, and who will notice anyway? Just guys like Richard and me. '-) I pointed this out, because Chris asked me for an example of a modern audio device using ceramic coupling caps, and here it is.
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Old 19th February 2018, 03:53 PM   #122
chris719 is offline chris719  United States
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John Curl's Blowtorch preamplifier part III
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Originally Posted by RNMarsh View Post
I do not know about that. Get some and try them and then let us know. That 'beat sound' and distortion from it is interesting also and could apply to many other cap types.


THx-Richard
The "beat sound" is just a poor translation for piezoelectric effect. These caps are not bad but ultimately don't seem very interesting because they are at best equivalent to metallized polyester according to their datasheet.

Maybe useful in a few applications to replace a high K MLCC with something that is still low ESL, but for audio you can just use through-hole parts. They aren't really that small either- smallest package in stock is 1206 and coupling values are 2220.
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Old 19th February 2018, 04:02 PM   #123
billshurv is offline billshurv  United Kingdom
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John Curl's Blowtorch preamplifier part III
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Originally Posted by hhoyt View Post
to hear Giles Martin's CD (no HD release yet) remaster of that obscure album Sgt. Peppers? Not that anyone needs to hear it again, but I recently had an opportunity to compare the previous best George Martin remastered FLAC version to the new Giles Martin CD, and I hope Giles remasters a lot more in the future. It is a truly amazingly 3D mix with phenomenal separation and clarity of all instruments individually tracked compared to previous attempts by his father, of which I have many (yeah, Beatles freak too...). Highly recommended!

Cheers!
Howie
I haven't heard it, but I have watched a program where they explain how they did this version, going back to the 4 track recordings and re-mixing from scratch in a DAW. This is more than just re-mastering. It's a recreation.

I think if all the HD 're-masters' went back to the 24/48track originals, converted those to digital and recreated the final mix from scratch their might be something in it, but so far I have not found a case where the HD is superior to the redbook. If anyone has some examples I would be interested.
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Old 19th February 2018, 04:10 PM   #124
PMA is offline PMA  Europe
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Speaking about coupling capacitors "distortion", I have the series of 6 Cyril Bateman's articles published in Electronics world since July 2002. IMO it must be emphasized that he was not testing the capacitors as coupling caps (= almost zero voltage across the cap), but he was forcing voltage on the capacitor terminals via small resistors. That means, he was measuring distortion of voltage across the capacitor, which may make sense only in case if they are used in crossover filters, but makes no sense in case of coupling capacitors when the F(-3dB) high pass filter point must lie well below 20Hz, thus there is no voltage across the capacitor in the audio band. I also made my own tests and never found distortion behind the coupling capacitor in a properly calculated CR coupling circuit. Only if the capacitor started to be loaded and acted as filter, then especially high Q ceramics like X7R started to distort, which is expectable for the dielectric well known as nonlinear.

As an example, I have just now measured a 4.7uF/6.3V polar tantalum capacitor, age about 30 years (should be very bad, right??) connected as a coupling capacitor loaded with 18 kohm resistor. The output voltage is measured on the terminals of the loading resistor. Thd vs frequency plot is shown, with loopback in green color and with inserted CR in grey color. Though the distortion method is not very sensitive, about 0.001% (-100dB), it can be seen that the measurement with CT inserted perfectly follows the loopback curve. Input level is 1Vrms. So, with 1Vrms input and -100dB distortion resolution and 18k load, even the polar tantalum 4.7uF capacitor does not insert additional distortion. In other words, there is no AUDIBLE distortion added. The tantalum is not DC biased and is NOT the bipolar type. It just has no voltage across its terminals.
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Old 19th February 2018, 04:20 PM   #125
spaceistheplace is offline spaceistheplace
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Pretty light jab. I admit the joke about Neil and his buddies driving around in their '72 caddie hear the difference was not necessary. But doesn't this underscore the controversy we have here, professional engineers whose business is making recordings don't hear any difference?


I agree.

But I would also like to point out that this behavior has been going on for some time in this field, not beginning with digital. I donít see those who are in the camp you are trying to persuade suddenly having a eureka moment and seeing the smokescreen. I donít think the issue is lack of credible evidence. But I think itís noble you are trying.

If you want real answers follow the money not the logic.

Anyhow, i will do my part to begin to refer to my hi-fi as my ďbest I can presently do fiĒ ;-)

Quote:
Originally Posted by scott wurcer View Post
I wish he took his idea of source material back one more step, if you know what I mean (I don't find his catalog compelling). This is typical of audiophile labels these days.

This is the key. It precludes all other considerations. If the catalogue is not worth listening to, what is the point of even having the discussion?

If he could plop me in the middle of a Taj Mahal Travellers session in all its glory Iíd feel a whole lot differently.

I know you arenít an Apple fan, but imho Apple/ iTunes music has done the best job that I can see of digitizing a lot of unobtainium recordings you might care about.
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Old 19th February 2018, 04:49 PM   #126
hhoyt is offline hhoyt  United States
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John Curl's Blowtorch preamplifier part III
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Originally Posted by anatech View Post
...There are other good tuners, and I think you should concentrate on ones that can sound good. The RF stuff can be set up, but if the audio is a lost cause, there isn't any reason to consider that particular tuner.-Chris
Well said, Chris! As a broadcast engineer I have been fixing, aligning and collecting FM tuners for a while (still have my ST1610A/1000A setup) and found some of the most sensitive front-end and selective IF designs were hooked to some of the worst sounding detectors and audio circuits, models from many top brands come to mind.

The models I currently use which had the best overall performance including audio were all made between 1976 and 1982, the peak period for FM tuner development.

My main tuner is a modded Kenwood 600T, which in has great RF performance and actual useful metering, and I really like the audio quality of the Kenwood pulse-count detector. It does not have the grainy sound so many quadrature and PLL detectors can have. The same general audio excellence can be found in the less-expensive KT7500 and 8300, both which also respond well to audio modding. I also love the McIntosh MR78, which uses tuned LC IF filtering as opposed to the ceramic filter IF more commonly used and sounds great although it's RF performance is not state-of-the-art. I own a Revox 760 (with custom oak side panels no less) and while it is a fine tuner I had in my main system for a few years it was replaced by the Kenwood 600T which had better RF performance and which sounded equally as good...just my experience. I'm open to offers on my Revox B760 if anyone is interested? A tuner I have heard in the past and was wowed by (although maybe by the price tag as well) is the Sequerra Model 1s, which is absurdly expensive, though maybe JC can get his buddy to lend him one?

I also own the more modern (discontinued) Sony XDR-F1HD, and it's continuously variable IF bandwidth makes it an outstanding RF performer, but not necessarily a great sounding tuner. Many of the proponents of that tuner point out it's HD performance, and I am just not a fan of HD-FM. It is a lossy digital scheme which sounds compressed to me and when our Harris reps demonstrated it to us I was not impressed, it had a "tight" sound as opposed to the open analog channel, although it is hard to separate out audio effects from processing from the sound of the HD-FM scheme itself. I have been opposed to the IBOC scheme, since those digital subcarriers often cause audible interference with the main analog carrier, especially on some otherwise excellent sounding tuners. The situation is much like CD vs. MP3: the public in general doesn't care about fidelity, just choice, and adding HD subcarriers gives them that, as well as giving a station owner more revenue sources. Don't get me started...

Cheers,
Howie
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Old 19th February 2018, 04:57 PM   #127
john curl is offline john curl  United States
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Once again PMA, it is not distortion in an input cap that is most important, but the FEEDBACK CAP, that can't use 18K as a load. However, all polar caps have significant DA, much more than even Mylar, and even with using Mylar, people have told me, can be audible in my designs. I chose Mylar more than 40 years ago, thinking that it could do the job, but it didn't from listening criticism by others who were associated with my designs at the time. What a disappointment it was! Then I had to look at PP, which was much larger, and more expensive. Finally, I just switched to servos, and have never looked back. Even the JC-3 JR phono stage is servoed. That is part of what makes it successful.
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Old 19th February 2018, 05:53 PM   #128
anatech is offline anatech  Canada
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John Curl's Blowtorch preamplifier part III
Hi John,
Quote:
Chris asked me for an example of a modern audio device using ceramic coupling caps, and here it is.
That wasn't this Chris. I wonder how we can keep people straight with only their first name used.

Chris

Edit: I don't think that Sony ever made anything that sounded good. I can't remember ever servicing a Sony and wanting to hear it longer or to take it home. They usually also make some unfortunate design decisions that can't be fixed.
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Old 19th February 2018, 06:02 PM   #129
RNMarsh is offline RNMarsh  United States
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caps --->

Capacitor distortion overview

http://www.tadiranbatteries.de/pdf/a...capacitors.pdf


-RNM
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Old 19th February 2018, 06:04 PM   #130
anatech is offline anatech  Canada
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John Curl's Blowtorch preamplifier part III
Hi John (again),
I just remembered that the new Cyrus stuff uses ceramic surface mount components in their audio products. By new, I mean since sometime early in the current century. Cyrus is generally designed very well and are more advanced in design than most other products.

When I toured the factory in 2004, I met the designers and got a chance to spend some time with them talking about their current designs. The used AP analysers and some HP equipment. In addition, each design had to make it past their listening room, and they really do listen to new products carefully. This is right in line with my beliefs on how to design audio equipment. Their service positions each have an AP and every repair must pass spec when done.

The only bad products they made were the CD players that used the Sony VAM CD mechanisms. Terrible design, basically junk. They designed their own transport after that experience. I know for a fact that they were very frustrated dealing with Philips.

-Chris
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