Scott is right, (see how I can be professional regarding you Scott?) the 2SK103 is usually much better than what you measured, perhaps 10dB better. The Y select (1.2-3ma) is the first clue. Try at least a GR or even a V in the same series and you will get better performance.
A good practical estimate of the jfet noise is to invert the working Gm of the part, in this case, 1/1000umho = 1000ohms = 4nV/rt Hz. Significantly more than that, you have a bad batch with very high 1/f noise. You have significantly more noise, so you have a batch or measurement problem.
A good practical estimate of the jfet noise is to invert the working Gm of the part, in this case, 1/1000umho = 1000ohms = 4nV/rt Hz. Significantly more than that, you have a bad batch with very high 1/f noise. You have significantly more noise, so you have a batch or measurement problem.
The test circuit (of Scott's design) includes an autobiasing mechanism so that ALL DUTs are tested with the same bias, around 1.2mA, irrespective of Idss.
We know it is working because it produces the expected noise level of a range of other JFETs, including 2SJ74, 2SK170, 2SK369, 2SK372, BF862, 2SK117 ......, etc.
Patrick
We know it is working because it produces the expected noise level of a range of other JFETs, including 2SJ74, 2SK170, 2SK369, 2SK372, BF862, 2SK117 ......, etc.
Patrick
No, it's really fine, although you need to have some pretty thorough test schemes to really dig down the statistical power.
I just grew really tired of impossible hearing claims, e.g. < -100 dB errors being "clear as day" and general refusal to do due diligence. So I'm just going to pass on that repeated discussion.
Similar thing happened to me several years ago. Bought an audio recording interface that I though should be fine based on the numbers, but it wasn't fine at all when I listened to it.
A lot has transpired since then, including here at DiyAudio. There was a time when it might have been wiser on your part not to describe your experience.
Interesting times we live in, I guess.
If you are looking for ear MEASUREMENTS, canyoncruz, then you are correct. But discerning listening differences usually takes maturity and directed experience. Of course, you might choose your food choices with a 10 year old as well, and perhaps even wine differences, (they don't have to swallow the wine). '-)
It would be more work than merely listening to a stereo for a given period of time.
The number given to develop expertise that simon7000 referred to is for "directed practice." That means constantly working on skill improvements, usually under the direction of some kind of teacher or mentor.
The number given to develop expertise that simon7000 referred to is for "directed practice." That means constantly working on skill improvements, usually under the direction of some kind of teacher or mentor.
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What's so strange about that? Why would one lose one's hearing, if one is not overdoing it?
If listening to a decent tuner (in my case, a Revox B760, said on an FM dedicated site to be one of the best eight tuners ever made) attached to one's stereo system counts, it would make me listen to my stereo over 12 hours a day, almost 365 days a year. Fortunately for me, I do have several technically and musically very good quality stations available 24/7 I dislike silence, and am known to pause in my work just to be able to hear a song I like through, so it's not all idle listening to whatever.
But I am not a headbanger, just decent loudness levels fir for home, and if necessary a crossover to headphones.
I remember reading about one of Stevie Ray Vaughan's recording sessions where he played thru 10 amplifiers. They mostly recorded live so some of the smaller amps were in adjoining room so the mics could pick them up. He kept hearing a distortion no one in the studio heard. It turns out it was one of the small (15 W) amps in the next room.
If you ever saw Stevie Ray Vaughan play, you can probably surmise he had ear damage. But did he also have golden ears? Maybe better than a journalist audiophile?
If you ever saw Stevie Ray Vaughan play, you can probably surmise he had ear damage. But did he also have golden ears? Maybe better than a journalist audiophile?
Perhaps he did, for guitar amps at least. His listening expertise may have mostly in that area, however. Hard to say at this point.
Also, maybe better if we could avoid the term Golden Ears. There are connotations to that which may not be helpful here.
In addition, learned listening expertise is probably much more in the brain than in the ears. Would you want to say Golden Brain? I wouldn't.
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That's my argument, what people hear critically is learned and somewhat faddish. I remember the first time I listened to a high end system, I was a kid in the early 70's. We were visiting a friend in the Hollywood Hills and they had a listening room with a giant system. I never made it out to the pool. I remember the impact on me. Didn't know how to listen, it was simply the best sounding system at that point of my life and i couldn't get enough.
It can be faddish or not. People are exceedingly complex, and they change over time and with circumstances.
That being said, research indicates people on average tend to like music they were exposed to a lot during their teens and very early 20's.
Certainly some people who were in that age group during the height of the loudness wars when extreme clipping distortion became common still think it sounds good, or that it connects emotionally more than other music. Is that a fad exactly, more some kind of learned conditioning, or something else? Whatever it is, calling it a fad doesn't seem the best fit to me.
That being said, research indicates people on average tend to like music they were exposed to a lot during their teens and very early 20's.
Certainly some people who were in that age group during the height of the loudness wars when extreme clipping distortion became common still think it sounds good, or that it connects emotionally more than other music. Is that a fad exactly, more some kind of learned conditioning, or something else? Whatever it is, calling it a fad doesn't seem the best fit to me.
Same here ---- listen every day, most of the day.... sometimes very attentive and sometimes not... but same room etal every day for who knows how long.... started 'listening' from <1 year old. Mother would place my crib in front of record player console and play a stack of classical music LP and 45's. That was my entertainment.
When I got my first job (summer job -- brutal manual labor) I spent my whole pay on LP's. At the end of the summer I had no money for college, car gas etc. Didn't think ahead much then.
You have to love music, listen a lot and you can detect changes others cannot.
-Richard
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I would add to that, as a service tech one gets to hear an extraordinary range of brands, models and types of audio gear.
Whilst running unchanging and good bench monitor/reference gear., one learns to hear the sound of the DUT perfectly clearly.......aural training 50 times per week.
From this one comes to clearly hearing minor subtleties and signatures including 'house' sounds.
From this one learns correlations of what causes 'house' sounds.
One also gets to hear examples of famous/renouned gear and compare to reviews.
In the audio world there is the 10,000 hours experience and there is also the 10,000 examples experience, both are required.
Dan.
Whilst running unchanging and good bench monitor/reference gear., one learns to hear the sound of the DUT perfectly clearly.......aural training 50 times per week.
From this one comes to clearly hearing minor subtleties and signatures including 'house' sounds.
From this one learns correlations of what causes 'house' sounds.
One also gets to hear examples of famous/renouned gear and compare to reviews.
In the audio world there is the 10,000 hours experience and there is also the 10,000 examples experience, both are required.
Dan.
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