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#1
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Sorry for the intrusion, but this may interest some of the denizens of
rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac |
#2
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On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote:
Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. d |
#3
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In rec.audio.tubes Don Pearce wrote:
On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote: Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. Eh, I've already put a bid ![]() --- ************************************************** **************** * KSI@home KOI8 Net The impossible we do immediately. * * Las Vegas NV, USA Miracles require 24-hour notice. * ************************************************** **************** |
#4
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"Sergey Kubushin" wrote in message
In rec.audio.tubes Don Pearce wrote: On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote: Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. Eh, I've already put a bid ![]() If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. |
#5
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In rec.audio.tubes Arny Krueger wrote:
"Sergey Kubushin" wrote in message In rec.audio.tubes Don Pearce wrote: On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote: Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. Eh, I've already put a bid ![]() If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. I also have several different test records but none of them addresses testing frequency response for RIAA compliance. They are quite useful for other testing aspects though. --- ************************************************** **************** * KSI@home KOI8 Net The impossible we do immediately. * * Las Vegas NV, USA Miracles require 24-hour notice. * ************************************************** **************** |
#6
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"Sergey Kubushin" wrote in message
In rec.audio.tubes Arny Krueger wrote: "Sergey Kubushin" wrote in message In rec.audio.tubes Don Pearce wrote: On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote: Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. Eh, I've already put a bid ![]() If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. I also have several different test records but none of them addresses testing frequency response for RIAA compliance. They are quite useful for other testing aspects though. Many of the better oldies from "the days of" , like the CBS STR series, are still very good by modern standards. Most people seem to have bought test records and then never used them, as most of the ones I got from eBay were pristene. In contrast, a modern test record like the HFN LP run about $50 or more. |
#7
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Arny Krueger wrote:
If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. Were any of them any good? It only takes one play with a Pickering to wreck the square wave tracks. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#8
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"Scott Dorsey" wrote in message
Arny Krueger wrote: If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. Were any of them any good? It only takes one play with a Pickering to wreck the square wave tracks. Many seemed to be absolute virgins. |
#9
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In article ,
(Scott Dorsey) wrote: Arny Krueger wrote: If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. Were any of them any good? It only takes one play with a Pickering to wreck the square wave tracks. What if I might ask makes the Pickering apparently worse in this regard than other pickups? -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#10
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John Byrns wrote:
In article , (Scott Dorsey) wrote: Arny Krueger wrote: If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. Were any of them any good? It only takes one play with a Pickering to wreck the square wave tracks. What if I might ask makes the Pickering apparently worse in this regard than other pickups? Oh, it was just the normal "cheap consumer cartridge that doesn't track very well" example that my boss liked to use in the seventies. His four tiered description of mastering jobs was: - It'll track on a Close 'N Play - It'll track on a Pickering - It'll track on a 681EE - It's untrackable. I have made plenty of records these days which he'd consider untrackable back then, because the folks using vinyl today are mostly people using better quality equipment than the average listener was back then. Still, you'd be surprised... and if it won't track on a Close 'N Play, the jukebox companies won't buy it.... --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#11
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In rec.audio.tubes Arny Krueger wrote:
"Sergey Kubushin" wrote in message In rec.audio.tubes Arny Krueger wrote: "Sergey Kubushin" wrote in message In rec.audio.tubes Don Pearce wrote: On Tue, 24 Feb 2009 10:44:09 -0800, isw wrote: Sorry for the intrusion, but this may interest some of the denizens of rec.audio: I've just put on eBay a CBS Laboratories STR 130 RIAA Test Record. It can be accessed as Item # 280316380901. Because of the special nature of the item, I've given it a ten-day listing. This may be your last chance to get such a disc; if you need it, good luck. Isaac There are plenty of vinyl newsgroups out there - post to some of those too. Eh, I've already put a bid ![]() If its a good deal, go for it. Test records are not terribly uncommon on eBay. I obtained about a half dozen during a few weeks of watching, none for more than about $10. I also have several different test records but none of them addresses testing frequency response for RIAA compliance. They are quite useful for other testing aspects though. Many of the better oldies from "the days of" , like the CBS STR series, are still very good by modern standards. Most people seem to have bought test records and then never used them, as most of the ones I got from eBay were pristene. Yep, all those I've got from Ebay were pristine. And they do not have to be especially good or audiofool. This particular one I need for testing my MC/MM preamps with particular cartridges because they have aperiodic correction that must be adjusted to the cartridge it works with. Inverse RIAA network can not do this and the best way to test everything is a proper test record. That allows for testing of the entire path, from cartridge/tonearm to the preamp output. In contrast, a modern test record like the HFN LP run about $50 or more. They are not modern, just less vintage, yeah? ![]() --- ************************************************** **************** * KSI@home KOI8 Net The impossible we do immediately. * * Las Vegas NV, USA Miracles require 24-hour notice. * ************************************************** **************** |
#12
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"Sergey Kubushin" wrote in message
In rec.audio.tubes Arny Krueger wrote: "Sergey Kubushin" wrote in message I also have several different test records but none of them addresses testing frequency response for RIAA compliance. They are quite useful for other testing aspects though. Many of the better oldies from "the days of" , like the CBS STR series, are still very good by modern standards. Most people seem to have bought test records and then never used them, as most of the ones I got from eBay were pristene. Yep, all those I've got from Ebay were pristine. And they do not have to be especially good or audiofool. They are a varied lot ranging from those sold by Poular Science magazine, to Stereo Review, to CBS labs. This particular one I need for testing my MC/MM preamps with particular cartridges because they have aperiodic correction that must be adjusted to the cartridge it works with. Inverse RIAA network can not do this and the best way to test everything is a proper test record. That allows for testing of the entire path, from cartridge/tonearm to the preamp output. That is IME a very important procedure, that improves sound quality. In contrast, a modern test record like the HFN LP run about $50 or more. They are not modern, just less vintage, yeah? ![]() AFAIK the current high-priced spread are very recent masterings/cuttings/pressings, not NOS. I own several. |
#13
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In rec.audio.tubes Arny Krueger wrote:
"Sergey Kubushin" wrote in message In rec.audio.tubes Arny Krueger wrote: "Sergey Kubushin" wrote in message I also have several different test records but none of them addresses testing frequency response for RIAA compliance. They are quite useful for other testing aspects though. Many of the better oldies from "the days of" , like the CBS STR series, are still very good by modern standards. Most people seem to have bought test records and then never used them, as most of the ones I got from eBay were pristene. Yep, all those I've got from Ebay were pristine. And they do not have to be especially good or audiofool. They are a varied lot ranging from those sold by Poular Science magazine, to Stereo Review, to CBS labs. This particular one I need for testing my MC/MM preamps with particular cartridges because they have aperiodic correction that must be adjusted to the cartridge it works with. Inverse RIAA network can not do this and the best way to test everything is a proper test record. That allows for testing of the entire path, from cartridge/tonearm to the preamp output. That is IME a very important procedure, that improves sound quality. Yep. In contrast, a modern test record like the HFN LP run about $50 or more. They are not modern, just less vintage, yeah? ![]() AFAIK the current high-priced spread are very recent masterings/cuttings/pressings, not NOS. I own several. I've never seen them. But anyways, I do not make phono preamps for living so I simply don't need them. --- ************************************************** **************** * KSI@home KOI8 Net The impossible we do immediately. * * Las Vegas NV, USA Miracles require 24-hour notice. * ************************************************** **************** |
#15
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Ben Bradley wrote:
I was about to ask (in my best Frank Zappa voice) if that's a Technics Close 'N' Play, or a Kenner Close 'N' Play, but I see by your mention of the seventies it has to be Kenner. I can only imagine this thing sitting in an LP/45 test facility: http://www.youtube.com/watch?v=QMoCEHkWdX4 No, this is some kind of IMPROVED Close 'N Play which has an electronic amplifier in it. The original one was purely acoustic, with a diaphragm that was vibrated by the stylus. It was EVEN NASTIER. And yes, my boss had one sitting on his desk to threaten mastering engineers with. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#16
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I still have all my CBS test records, plus the HFN&RR quad disks.
I'm going to tell a story that will get Arny very, very angry... Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. I still sometimes wonder what it might be. |
#17
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![]() William Sommerwerck wrote: I still have all my CBS test records, plus the HFN&RR quad disks. I'm going to tell a story that will get Arny very, very angry... Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. I still sometimes wonder what it might be. So you measured and found a rising treble response of +14dB at 20kHz above the reference 1kHz? And yet music sounded like there was a big treble cut. Apart from the possibility your hearing is very poor, what you heard with music and what you measure doesn't corelate at all. But you have to be aware of how they may have equalised the test record. Some do not simply have anounced test frequencies that have been recorded using the standard the RIAA recording eq. I searched for and could NOT find a test record with its announced frequencies properly eq'd for RIAA and not one of the 3 test records I have have such a simple set of test tones so that you don't have to make calculations from the weird response you may initially measure. I don't bother testing carts anymore because of the problem of not being able to get a decent test record. They have everything you don't need and nothing that you really want. Last time I tested 2 MCs and two MMs, the responses were weird with rising HF response, but all much the same, and there was serious distortion above 5kHz, like a wriggle in the sine at each zero crossing of about 20% of the main wave amplitude. Judging by the sound of my Denon 103R there isn't much wrong with the response. When I changed to the Denon from a Shure V15, the sound was cleaner, and just better, but the response was about the same. Patrick Turner. |
#18
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"Patrick Turner" wrote in message
... William Sommerwerck wrote: I still have all my CBS test records, plus the HFN&RR quad disks. I'm going to tell a story that will get Arny very, very angry... Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. I still sometimes wonder what it might be. So you measured and found a rising treble response of +14dB at 20kHz above the reference 1kHz? And yet music sounded like there was a big treble cut. Apart from the possibility your hearing is very poor, what you heard with music and what you measure doesn't correlate at all. Well, duh, yes. That was the point. But you have to be aware of how they may have equalised the test record. Some do not simply have anounced test frequencies that have been recorded using the standard the RIAA recording EQ. Stop. I was and I am. The record had RIAA EQ. Furthermore, I had tested other pickups with this disk, and their responses were reasonably flat and fairly close to published specs. I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. |
#19
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I neglected to mention (that it should not have been necessary) that I
measured the full response of the pickup, not at just one or two frequencies. I don't remember the exact curve, but it showed a gradual, then rather steep, rise in HF response. And, yes -- though, again, I shouldn't have to say it -- the response was measured with the same arm, 'table, preamp, etc, used to listen to music. |
#20
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"William Sommerwerck" wrote in
message I still have all my CBS test records, plus the HFN&RR quad disks. I'm going to tell a story that will get Arny very, very angry... Not at all. In fact it kinda excites me. Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) I'd like to see that curve. I suspect there was a bit of a dip in the 2-6 KHz range, maybe only a dB or two. I also suspect that the peak above 20 KHz was very narrow - basically a very lightly damped resonance. I also would like to know what was going on below 200 Hz. Low damping in the treble sometimes comes with low damping in the bass, so the response in the 80-160 range may have been down a bit, too. One problem is that 30 years ago, doing high precision measurements on vinyl was tough because we didn't have high-resolution FFT analyzers downloadable for free on the internet. We didn't have converters with +/- 0.05 dB response and 90 dB dynamic range sitting on the motherboards of our PCs. Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. You just might have been looking at it. I still sometimes wonder what it might be. Old data can look quite different when interpreted in the light of far newer information about audibility. |
#21
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In article ,
"William Sommerwerck" wrote: I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. A common way to cut a test disk is with constant amplitude below 500 Hz and constant velocity above 500 Hz, hope I got that straight. Many years ago when I worked at the phonograph factory, the CBS test record we used with the chart recorder was equalized that way. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#22
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"William Sommerwerck" wrote in message
... I neglected to mention (that it should not have been necessary) that I measured the full response of the pickup, not at just one or two frequencies. I don't remember the exact curve, but it showed a gradual, then rather steep, rise in HF response. And, yes -- though, again, I shouldn't have to say it -- the response was measured with the same arm, 'table, preamp, etc, used to listen to music. I think I owned the same cartridge -- at least, one of the Japanese cartridges Monster imported. My experience was identical to Mr. Sommerwerck's; the sound was dull, but the measurements showed a large peak in the high frequencies. I could never figure it out either. Peace, Paul |
#23
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John Byrns wrote:
In article , "William Sommerwerck" wrote: I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. A common way to cut a test disk is with constant amplitude below 500 Hz and constant velocity above 500 Hz, hope I got that straight. Many years ago when I worked at the phonograph factory, the CBS test record we used with the chart recorder was equalized that way. The RIAA standard is close to constant amplitude with a small boost in the mid frequencies. Cheers Ian |
#24
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![]() William Sommerwerck wrote: "Patrick Turner" wrote in message ... William Sommerwerck wrote: I still have all my CBS test records, plus the HFN&RR quad disks. I'm going to tell a story that will get Arny very, very angry... Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. I still sometimes wonder what it might be. So you measured and found a rising treble response of +14dB at 20kHz above the reference 1kHz? And yet music sounded like there was a big treble cut. Apart from the possibility your hearing is very poor, what you heard with music and what you measure doesn't correlate at all. Well, duh, yes. That was the point. Its very surprising to me that you could have a cart that gives a huge measured boost to treble and yet with music it sounds like it had no treble. I find this hard to believe. Most carts that are "bright sounding" also measure with too much treble. OR, they have little bass, all relative to 1kHz of course. With a poor bass response the music can sound thin and washed out. But you have to be aware of how they may have equalised the test record. Some do not simply have anounced test frequencies that have been recorded using the standard the RIAA recording EQ. Stop. I was and I am. The record had RIAA EQ. Furthermore, I had tested other pickups with this disk, and their responses were reasonably flat and fairly close to published specs. I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. I recall one test record I tried to use was not cut using RIAA. I recall that above and below 500Hz it had constant velocity or constant amplitude, I am not sure which exactly, but it wasn't RIAA. Patrick Turner. |
#25
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![]() William Sommerwerck wrote: I neglected to mention (that it should not have been necessary) that I measured the full response of the pickup, not at just one or two frequencies. I don't remember the exact curve, but it showed a gradual, then rather steep, rise in HF response. And, yes -- though, again, I shouldn't have to say it -- the response was measured with the same arm, 'table, preamp, etc, used to listen to music. The exact shape of the peak in treble response is important to know. Supppose you had a peak at HF at say +14dB at 20kHz but at 10kHz it was only +3dB, many people with hearing cut off at 7kHz, and with tinnitus, would maybe struggle to notice anything was wrong with the response. A young person with excellent hearing might notice the brightnes, but it wouldn't annoy them because nothing much does and they happily tolerate sound of horrible quality which really annoys people over 40. I often struggle to understand the sound tracks on movies. Once upon a time the movie makers chose actors with fine voices and diction. Then as soon as something was said, noise and music levels were eased down, and despite the noise and distortions of 1935 movies, the story could be followed because people didn't garble or mumble into a microphone or speak their lines too fast and the noise and music was minimal. So these days sound tracks make big demands on people to concentrate very hard to follow the story, and its mainly older men who fail to follow stories because of their treble cut off and tinnitus and lack of brain area relating to language and sound, something females have in greater abundance. To get over the problem of hearing music being dull and lifeless, or movie sound ruining the story because a man doesn't get critical spoken words, a boost to treble may be a blessing. If someone listens to 3 violinists playing at close range of 2 metres and seated in front of a wall right behind them you'll find they sound very much brighter, ie, screachy and scratchy than how you'd hear them in a recording. One needs to be seated about 5 metres away before the sound becomes "about right" to satisfy our expectations for a nice muse with music. Anyway, if the rise in treble response was +3dB at 2 kHz and rising at nearly 3dB / octave then by 20kHz the response would be +10dB and about what a well designed treble tone control should provide if needed, except it shouldn't ever be needed. Such a boost in treble would sound a lot brighter to an older person than if there was a sharp peak after 10kHz. Patrick Turner. |
#26
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![]() John Byrns wrote: In article , "William Sommerwerck" wrote: I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. A common way to cut a test disk is with constant amplitude below 500 Hz and constant velocity above 500 Hz, hope I got that straight. Many years ago when I worked at the phonograph factory, the CBS test record we used with the chart recorder was equalized that way. Indeed John. I think this is the one I have. So what kind of preamp filter schematic is needed to produce a flat response when plotting curves of response using announced test tones and an oscillosope to make a line of dots on a page for a graph to record voltage levels? Patrick Turner. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#27
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On 27 Feb, 01:00, Patrick Turner wrote:
John Byrns wrote: In article , *"William Sommerwerck" wrote: I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. A common way to cut a test disk is with constant amplitude below 500 Hz and constant velocity above 500 Hz, hope I got that straight. *Many years ago when I worked at the phonograph factory, the CBS test record we used with the chart recorder was equalized that way. Indeed John. I think this is the one I have. So what kind of preamp filter schematic is needed to produce a flat response when plotting curves of response using announced test tones and an oscillosope to make a line of dots on a page for a graph to record voltage levels? Patrick Turner. -- Regards, John Byrns Surf my web pages at, *http://fmamradios.com/- Hide quoted text - - Show quoted text - and its mainly older men who fail to follow stories because of their treble cut off and tinnitus and lack of brain area relating to language and sound, something females have in greater abundance. Are you sure Patrick, Its usually the whinging and nagging that spoils a good film for me :-) Perhaps men gradualy learn to turn down the background noise? and that is the problem. Matt. |
#28
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It was up something like 14dB at 20kHz. (No, there was no
significant suckout in the "presence" region.) I'd like to see that curve. I suspect there was a bit of a dip in the 2-6 KHz range, maybe only a dB or two. I know what that sort of dip sounds like, and this pickup was rather darker and duller than that. Most pickups of that era -- MF or MC -- suffered from this problem. I also suspect that the peak above 20 KHz was very narrow - basically a very lightly damped resonance. It certainly looked like a tip/vinyl resonance. The test disk didn't go beyond 20kHz, so I don't know how wide the peak was. I also would like to know what was going on below 200 Hz. Low damping in the treble sometimes comes with low damping in the bass, so the response in the 80-160 range may have been down a bit, too. The damping that affects LF behavior has little or no effect on the tip/groove resonance. The latter is often undamped or underdamped -- especially in high-inductance designs -- to mechanically compensate for electrical rolloff. Old data can look quite different when interpreted in the light of far newer information about audibility. I never cared for the Denon 103C MC pickup because of its slight depression in that range. This pickup sounded much darker than that -- and it did not have a depression that would account for it. |
#29
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"Paul Stamler" wrote in message
... "William Sommerwerck" wrote in message ... I neglected to mention (that it should not have been necessary) that I measured the full response of the pickup, not at just one or two frequencies. I don't remember the exact curve, but it showed a gradual, then rather steep, rise in HF response. I think I owned the same cartridge -- at least, one of the Japanese cartridges Monster imported. My experience was identical to Mr. Sommerwerck's; the sound was dull, but the measurements showed a large peak in the high frequencies. I could never figure it out either. Corroborative testimony. Thank you. |
#30
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![]() "William Sommerwerck" wrote in message ... I still have all my CBS test records, plus the HFN&RR quad disks. I'm going to tell a story that will get Arny very, very angry... Not at all. In fact I answered this post a couple of days back, but I don't see the answer around, so I'll redo it. Around 30 years ago, Murray Zeligman, a well-known Baltimore audiophile and amp/speaker designer, handed me a Japanese MC pickup -- I forget who the importer was -- Monster? -- and asked me to listen to it (at home). "What do you expect me to hear?" He shook his head. "Just listen." I listened. The sound was extremely dull and lacking in life/detail. So I pulled out a CBS test disk and measured the response. It was up something like 14dB at 20kHz. (No, there was no significant suckout in the "presence" region.) I have no problem with this subjective result at all. First off, I'd bet that there was a broad dip in the 2-6 KHz range, maybe a dB or two. Secondly, Y2K psychoacoustics tells us that a narrow peak, or a complete brick wall at 20 KHz could be in another universe as far as audibility goes, provided that there is no collateral damage. OTOH, a broad dip in the 2-6 Khz range, even if less than 1 dB, is pretty easy to detect. Here's your relevant reference, copied from a JAES article: http://www.provide.net/~djcarlst/abx_crit.gif Note that a 1/3 octave wide peak (which is relatively broad compared to a cartrdige or tweeter peak) @ 20 KHz is off the chart. The chart says that you could have a 5 dB peak or a 5 dB 1/3 octave dip at 18 KHz, and it would be moot as far as causing an audible discrepancy goes. The chart is actually very conservative, and is about twice as demanding as actual audibility. So, we're saying that a 10 dB peak or dip at 18 KHz is still pretty moot. And, if the peak or dip is 18 KHz, or narrower than 1/3 octave, you have even more latitude. Thus I confidentlay say that a narrow peak 14 dB high, or a complete brick wall at 20 KHz could be in another universe as far as audibility goes, provided that there is no collateral damage (e.g., clipping in the electronics due to an overload from the peak). Obviously, there has to be /some/ measurement that correlate's with the pickup's sound. I still sometimes wonder what it might be. 30 years ago our understanding of psychoacoustics isn;t what it is today. |
#31
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![]() "Patrick Turner" wrote in message ... The exact shape of the peak in treble response is important to know. Exceedingly so. Supppose you had a peak at HF at say +14dB at 20kHz but at 10kHz it was only +3dB, many people with hearing cut off at 7kHz, and with tinnitus, would maybe struggle to notice anything was wrong with the response. You are being entirely too generous. The following chart is copied from a JAES article: http://www.provide.net/~djcarlst/abx_crit.gif It says that a 2.5 dB 1/3 octave wide peak at 10 KHz is not audible to even the most sensitive listener, and with a considerable safety margin. At 20 KHz the safe tolerance is off the chart! There are anecdotes about peaks and cuts at 20 KHz and up, but they often involved low order or low Q response variations that also had considerable effects at lower frequencies. Your typical cartdrige or tweeter resonance is very high Q. usually far more than Q = 3. |
#32
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On Feb 27, 9:51*am, "Arny Krueger" wrote:
"Patrick Turner" wrote in message ... The exact shape of the peak in treble response is important to know. Exceedingly so. Supppose you had a peak at HF at say +14dB at 20kHz but at 10kHz it was only +3dB, many people with hearing cut off at 7kHz, and with tinnitus, would maybe struggle to notice anything was wrong with the response. You are being entirely too generous. The following chart is copied from a JAES article: http://www.provide.net/~djcarlst/abx_crit.gif It says that a 2.5 dB 1/3 octave wide peak at 10 KHz is not audible to even the most sensitive listener, and with a considerable safety margin. At 20 KHz the safe tolerance is off the chart! There are anecdotes about peaks and cuts at 20 KHz and up, but they often involved low order or low Q response variations that also had considerable effects at lower frequencies. Your typical cartdrige or tweeter resonance is very high Q. usually far more than Q = 3. As many of you know, HF peaks like that can also be caused electrically by the interaction of the inductance of the phono cart and the capacitance of the cable and the input resistance of the phono preamp. Also another trick is to change the speed of the record to get more frequency points and you know since it is the same track and you are just changing the playback speed it is an exact "constant amplitude" situation. This works for tape decks too. Mark |
#33
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wrote in message
... On Feb 27, 9:51 am, "Arny Krueger" wrote: There are anecdotes about peaks and cuts at 20 KHz and up, but they often involved low order or low Q response variations that also had considerable effects at lower frequencies. Your typical cartdrige or tweeter resonance is very high Q. usually far more than Q = 3. As many of you know, HF peaks like that can also be caused electrically by the interaction of the inductance of the phono cart and the capacitance of the cable and the input resistance of the phono preamp. Not the issue with the cartridge being discussed here, which is a moving-coil design. Peace, Paul |
#34
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![]() bigwig wrote: On 27 Feb, 01:00, Patrick Turner wrote: John Byrns wrote: In article , "William Sommerwerck" wrote: I can think of only two ways to cut a test disk -- either constant velocity, or with a standard EQ. A common way to cut a test disk is with constant amplitude below 500 Hz and constant velocity above 500 Hz, hope I got that straight. Many years ago when I worked at the phonograph factory, the CBS test record we used with the chart recorder was equalized that way. Indeed John. I think this is the one I have. So what kind of preamp filter schematic is needed to produce a flat response when plotting curves of response using announced test tones and an oscillosope to make a line of dots on a page for a graph to record voltage levels? Patrick Turner. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/- Hide quoted text - - Show quoted text - and its mainly older men who fail to follow stories because of their treble cut off and tinnitus and lack of brain area relating to language and sound, something females have in greater abundance. Are you sure Patrick, Its usually the whinging and nagging that spoils a good film for me :-) Perhaps men gradualy learn to turn down the background noise? and that is the problem. Matt. I don't have a missus, wife, partner, shiela-in-tow or whatever one calls it when you have a bothersome source of noise and complaints about everything. When I did have such beings in my life and I had several, and the N&C got up to a seriously distracting level, and a root wouldn't shut it up, then I'd describe the benefits of the door and the life she could have outside of it. Most left, ashamed of how they'd treated me, and I gained my peace and quiet. Many men don't learn how to turn down background noise and it becomes less tolerable as age increases unless one goes deaf. I took noise very seriously after age 34 when the first tinnitus began which wouldn't go away. That just suddenly happened and in both ears and I became a bit anti social for a couple of years and since that time I used earmuffs with religious ferver when doing my building work. When I went out to bars and clubs and discos I wore ear plugs. Its a lot better now than it was because of my good habits. Before deafness usually ppl's ears create noise of their own. Gradual fading of hearing without noise problems would be OK and all you'd have to do is turn up the volume. But it just isn't so. Much audio is doomed beyond a fix, and no amount of fiddling with a graphic eq and a good pair of headphones will allow a man to enjoy the story of a movie. Women do have better abilities at understanding what they hear. ( But almost no ability to take any notice of a man telling them something they don't like hearing, but need to hear or else ) . So many women can understand the words of an opera, pop tune, and hum along if they are musical ( many have super hearing but no musicality ) . Rye Cooder and Taj Mahal are about the only two performers I liked and who I could understand easily. And both sang songs which had meaning, humour, soul, etc. I need the subtitles for operas and pop music, and can barely hum along, but I just like the sound of music; I am not straining to find meaning or follow a story with music; the music washes over your mind sensuously and there isn't any need for it to have meaning, it need only have feeling - rather like good sex. Meanwhile, a minority of men have very good hearing and musical brains and excellent linguistic abilities. Almost none of them are able to understand simple things like impedance, or how to use a screw driver. Patrick Turner. |
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