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In article , Eeyore
wrote: Jim Lesurf wrote: Eeyore wrote: If you look at what Stewart wrote (Hi, Stewart! :-) ) that seems to be comparing the effect of the room reverb with a situation where such reverb would be absent. At least that is my understanding of his saying, "...having them in an average living room gives you another 3dB or so of reverberant sound..." If that is wrong, I'm sure he will correct me, but that was what I then was referring to. Sorry if you didn't follow what I wrote. It's certainly true that a domestic room will have a far or ambient field that is greater than an anechoic chanber. Ever been in one btw ? Yes. Although 'retired' as an academic I still have my old University anechoic chamber as a 'lab'. (This translates to my also using its anteroom as my 'office' when in the physics building. :-) ) They're really odd. Indeed. :-) But then again does one listen to one's speakers at 1 metre distance usually ? so the SPL will have dropped off by X dB anyway by the time it reaches the sofa. Indeed. That will tend to happen. Are you familiar with nearfield and farfield measurements ? Yes - although you haven't said which particular mechanisms you have in mind for the factor(s) which affect how they differ, so I don't know which one(s) you have in mind. Have you read the article I referred to? Don't need to. In the near field, SPL will drop off at a rate of 6dB per doubling of distance (inverse square law). You haven't noticed that close-in that general assumption may break down? Consider what happens for example when your distance from the source is both less than a wavelength and less than a source diameter. Have you seen the AES papers, etc, that deal with sound levels close in? There is an analogy here with RF antennas. Near to the antenna the fields are not simply 'radiated in free space', and the change in level with nominal distance isn't inverse square. Nor is the wave impedance always the same as for open space propagation. So the difficulty here is that 'near field' has more than one defining meaning. For room acoustics it may mean relative to the boundary between being dominated by the direct radiation and the reverberant. But there are other effects. In the far field it's anyone's guess due to all the factors previously mentioned. Where the far field begins depends the size of your room and those other factors. Indeed. This is one of the reasons the MF 'sliderule' was somewhat misleading. BTW I just paused as I heard that Winter is approaching. The geese are flying over. So loud that I can hear them though the double-glazing. Nice sound, but sorry to wave farewell to summer... Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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In article
, wrote: Jim Lesurf wrote: However if your audiolab seems to you not to clip or overheat I doubt you will have a problem with most other = 50Wpc amps in terms of power unless your speakers drop to low impedance. The 8000 series tends to have pokey small heatsinks[1], but can IIRC deliver reasonably high peak currents. Above said, I haven't yet seen you say anything that makes me feel you would benefit from a new amp. Except perhaps in the way of feeling pleased to own and use a newer and - allegedly - 'better' one. Well the phono sockets needed replacing 18 months ago - I'd like an amp with sockets which don't self destruct. I'm not sure that phono-socket lifetime is a spec you will find quoted for most amps. :-) Why did they need replacing? The 8000 I have was given to me by a colleague as one of the drivers had blown, but the sockets seem fine. Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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In article , John Phillips
wrote: On 2008-10-14, Jim Lesurf wrote: In article , Eeyore wrote: Jim Lesurf wrote: I also still have my natty copy of the 'sliderule' he had sent out with one issue of HFN. This seems to imply I should change to a more powerful amp. I confess seeing this was one of the things that prompted my curiosity and lead to the HFN article I mentioned. Like yourself, I suspect, I've spent far more hours than any sane person should watching a scope display, etc, of power amp output whilst playing music to see what demands the music waveforms place on the amp and speakers. Some time ago John Crabbe reported published work in which listeners' perception of the same absolute loudness was rather different when they were listening in a large concert hall compared to a domestic listening room. This would suggest you do indeed need less in SPL terms at home than you get in the auditorium. Yes. I should make a public acknowledgement to JC here for that. I had read his articles and long since forgotten about them. He then saw my article and politely pointed out his own. I should have mentioned his articles as references for people to check out. Will do so if I get a chance to write more on the topic. He - and some readers - described the perception as being a sort of audio claustrophobia. This seems to be due to the short-time-delay nature of the reflections in small domestic rooms. So the work in my article may point at the cause. But at present it is hard to say for sure as there is a lack of experimental data so far as I am aware. Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
Amplifier power
In article , Eeyore
wrote: John Phillips wrote: Jim Lesurf wrote: Eeyore wrote: Jim Lesurf wrote: I also still have my natty copy of the 'sliderule' he had sent out with one issue of HFN. This seems to imply I should change to a more powerful amp. I confess seeing this was one of the things that prompted my curiosity and lead to the HFN article I mentioned. Like yourself, I suspect, I've spent far more hours than any sane person should watching a scope display, etc, of power amp output whilst playing music to see what demands the music waveforms place on the amp and speakers. Some time ago John Crabbe reported published work in which listeners' perception of the same absolute loudness was rather different when they were listening in a large concert hall compared to a domestic listening room. This would suggest you do indeed need less in SPL terms at home than you get in the auditorium. Because the nearfield and farfield are closer at home. You may be confusing cause and effect with a situation where the same mechanism is causing two effects. :-) Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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In article , Eeyore
wrote: Marky P wrote: tony sayer wrote: I Wonder how may pro recording bits of gear are around with 5532's;).. Just about most of it in current use. Are they at all similar to 5534's? Sure I used them in a phono pre-amp in the 80's, copied out of a R. A. Penfold book. Yes, they're the dual version and about 3dB noisier although not quite sure why. Not knowing why, my immediate suspicion was substrate noise caused by having two lots of bias currents. But that is just a spur of the moment guess. :-) FWIW I came to prefer the HA12017 as a general purpose audio op-amp. But I appreciate this is quite a weird choice. Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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In article , Eeyore rabbitsfriendsandrel
scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer |
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In article , Anton Gÿsen
scribeth thus tony sayer wrote: In article s.com, scribeth thus Jim Lesurf wrote: However if your audiolab seems to you not to clip or overheat I doubt you will have a problem with most other = 50Wpc amps in terms of power unless your speakers drop to low impedance. The 8000 series tends to have pokey small heatsinks[1], but can IIRC deliver reasonably high peak currents. Above said, I haven't yet seen you say anything that makes me feel you would benefit from a new amp. Except perhaps in the way of feeling pleased to own and use a newer and - allegedly - 'better' one. Well the phono sockets needed replacing 18 months ago - I'd like an amp with sockets which don't self destruct. Phileas Wonder if that was a poor batch none of mine are duff at all!... I believe it's a common problem with 8000As. Well I've got Four of them and their all fine;!... Funnily enough we've got four Band 1 transmitters , yes those frequencies are still used, and the cores in one have all disintegrated away whereas in the other their fine all about the same age!.. What is it that fails, the plastic moulding?.. -- Tony Sayer |
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In article ,
Robert Orban wrote: In article , says... ..and there's also this, which explicitly references peak level measurements: Pre- and Postemphasis Techniques as Applied to Audio Recording Systems JAES Volume 33 Issue 9 pp. 649-658; September 1985 Thanks for the above. I've now had a chance to have a quick read-though of it. I've probably missed things, and would need to check some of its references, but my initial reactions were... Firstly, that the levels reported are somewhat larger than asserted by others elsewhere - e.g. already in this thread is values from MF. This tends to support my suspicion that people assert numbers which may be misleading if they don't actually know where they came from at origin. Hence my preference for measured results. :-) I wonder how that may relate to the following. Secondly, that the paper doesn't give any real details of the peak meter used. For example, not the bandwidth when 'flat', nor the response times of the peak function. e.g. no value for underread of something like a bandwidth-limited impulse. This might well affect results, but hard to say more without any details. Thirdly that the stats seem to be on a 'peak per concert' basis IIUC. Makes me wonder what the time stats are as that might be a better guide. However, thanks, very interesting. :-) Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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"tony sayer" wrote in message
I Wonder how may pro recording bits of gear are around with 5532's;).. Tons and tons. But 5532s used right are really very good pieces, even by modern standards. And for the price...! The scarier part is how may pro recording bits of gear are around with TL074s, or even NJM4558s in the signal path. |
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On Oct 15, 8:52*am, Jim Lesurf wrote:
I'm not sure that phono-socket lifetime is a spec you will find quoted for most amps. :-) *Why did they need replacing? The plastic body just fell apart. It wasn't as if I kept plugging things in and out. I do leave the amp on continuously - could this have an effect? Phileas |
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tony sayer wrote:
In article , Anton Gÿsen scribeth thus tony sayer wrote: In article s.com, scribeth thus Jim Lesurf wrote: However if your audiolab seems to you not to clip or overheat I doubt you will have a problem with most other = 50Wpc amps in terms of power unless your speakers drop to low impedance. The 8000 series tends to have pokey small heatsinks[1], but can IIRC deliver reasonably high peak currents. Above said, I haven't yet seen you say anything that makes me feel you would benefit from a new amp. Except perhaps in the way of feeling pleased to own and use a newer and - allegedly - 'better' one. Well the phono sockets needed replacing 18 months ago - I'd like an amp with sockets which don't self destruct. Phileas Wonder if that was a poor batch none of mine are duff at all!... I believe it's a common problem with 8000As. Well I've got Four of them and their all fine;!... This site: http://www.theaudiocellar.co.uk/ specialises in, amongst other things, RCA socket replacements for Audiolab 8000As. I can't comment on 8000As because I have a new model 8000S. Funnily enough we've got four Band 1 transmitters , yes those frequencies are still used, and the cores in one have all disintegrated away whereas in the other their fine all about the same age!.. What is it that fails, the plastic moulding?.. I think so but I'm not sure. I've seen a couple on eBay which have been damaged in transit, so be careful if you ever move yours. |
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tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus Did you check the spec of the LME49720 ? http://www.national.com/pf/LM/LME49720.html They had to devise a special method to measure the THD without the noise dominating. They're not even that shockingly expensive. Shockingly enough in small quantities;!... From the likes of Farnell maybe £4 seems a lot but compare that to a $400 wooden volume control knob ! http://uk.farnell.com/1367613/semico...roduct.us0?sku =national-semiconductor-lme49720ma-nopb&_requestid=131459 That's only £2 per divine op-amp ! What were those $150 ones for then?.. Evaluation boards I think ? Wonder what Doc Martin would have to say;?... You lost me Him of Neve descent, didn't you work together once?.. DOC ? Martin ? I knew a Martin forget his surname who was in R&D. Not Martin (M.H) (Hartley) Jones PhD you mean ? He'd left by the time I arrived. I later did some work for him at Kelvin Hughes radar. Lovely chap. I still talk to him very occasionally. In fact I was just on the point of asking if he'd be happy to be a reference on my CV ! http://www.ibd-uk.com/members/jones-martin.htm Graham |
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tony sayer wrote: Eeyore scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! Graham |
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Jim Lesurf wrote: Eeyore wrote: John Phillips wrote: Jim Lesurf wrote: Eeyore wrote: Jim Lesurf wrote: I also still have my natty copy of the 'sliderule' he had sent out with one issue of HFN. This seems to imply I should change to a more powerful amp. I confess seeing this was one of the things that prompted my curiosity and lead to the HFN article I mentioned. Like yourself, I suspect, I've spent far more hours than any sane person should watching a scope display, etc, of power amp output whilst playing music to see what demands the music waveforms place on the amp and speakers. Some time ago John Crabbe reported published work in which listeners' perception of the same absolute loudness was rather different when they were listening in a large concert hall compared to a domestic listening room. This would suggest you do indeed need less in SPL terms at home than you get in the auditorium. Because the nearfield and farfield are closer at home. You may be confusing cause and effect with a situation where the same mechanism is causing two effects. :-) How large is your living room ? I can assure you it'll be an issue for many Americans. ;~) Graham |
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In article
, wrote: On Oct 15, 8:52 am, Jim Lesurf wrote: I'm not sure that phono-socket lifetime is a spec you will find quoted for most amps. :-) Why did they need replacing? The plastic body just fell apart. It wasn't as if I kept plugging things in and out. Interesting. Some polymers do deteriorate or change size shape with time. I recently had problems with an ancient cartridge where the plastic body had altered so the contact pins were loose. I do leave the amp on continuously - could this have an effect? Not sure. When I get a chance I'll try seeing if the ones of the 8000 I have have a similar problem, but they seemed OK when I last checked. Slainte, Jim -- Change 'noise' to 'jcgl' if you wish to email me. Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
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Jim Lesurf wrote: Eeyore wrote: Marky P wrote: tony sayer wrote: I Wonder how may pro recording bits of gear are around with 5532's;).. Just about most of it in current use. Are they at all similar to 5534's? Sure I used them in a phono pre-amp in the 80's, copied out of a R. A. Penfold book. Yes, they're the dual version and about 3dB noisier although not quite sure why. Not knowing why, my immediate suspicion was substrate noise caused by having two lots of bias currents. But that is just a spur of the moment guess. :-) FWIW I came to prefer the HA12017 as a general purpose audio op-amp. But I appreciate this is quite a weird choice. Weird isn't the word for it. ;~) Ever come across NJM 4560s, 4580s or 2068s ? From JRC/NJR (New Japan Radio Company). Not at all bad and the 4560 doesn't burn as much current but is a bit noiser than 5532s but still around TL07x levels. Btw - don't EVER confuse the NJM4562 with the LM4562. Someone dropped a minor clanger there and I think it was National, why is why the same device (apparently) turns up as the LME49720 as well. Graham |
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Jim Lesurf wrote: Robert Orban wrote: ..and there's also this, which explicitly references peak level measurements: Pre- and Postemphasis Techniques as Applied to Audio Recording Systems JAES Volume 33 Issue 9 pp. 649-658; September 1985 Thanks for the above. I've now had a chance to have a quick read-though of it. I've probably missed things, and would need to check some of its references, but my initial reactions were... Firstly, that the levels reported are somewhat larger than asserted by others elsewhere - e.g. already in this thread is values from MF. This tends to support my suspicion that people assert numbers which may be misleading if they don't actually know where they came from at origin. Hence my preference for measured results. :-) I wonder how that may relate to the following. Secondly, that the paper doesn't give any real details of the peak meter used. For example, not the bandwidth when 'flat', nor the response times of the peak function. e.g. no value for underread of something like a bandwidth-limited impulse. This might well affect results, but hard to say more without any details. Fast track and hold would be the only viable method. Graham |
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Arny Krueger wrote: "tony sayer" wrote I Wonder how may pro recording bits of gear are around with 5532's;).. Tons and tons. But 5532s used right are really very good pieces, even by modern standards. And for the price...! And to think they were around in the 1970s too ! And Philips / Signetics initially only thought they were going to sell it into the telecoms market because of the 600 ohm drive ! Philips = NE5532 Signetics ( Philips N.A.) = SE5532 btw. The scarier part is how may pro recording bits of gear are around with TL074s, or even NJM4558s in the signal path. TL07Xs are still ok for some stuff, especially because of the jfet front end but 4558s ? YUCK ! Graham |
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In article , Eeyore rabbitsfriendsandrel
scribeth thus tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus Did you check the spec of the LME49720 ? http://www.national.com/pf/LM/LME49720.html They had to devise a special method to measure the THD without the noise dominating. They're not even that shockingly expensive. Shockingly enough in small quantities;!... From the likes of Farnell maybe £4 seems a lot but compare that to a $400 wooden volume control knob ! http://uk.farnell.com/1367613/semico...rs-integrated- circuits/product.us0?sku =national-semiconductor-lme49720ma-nopb&_requestid=131459 That's only £2 per divine op-amp ! What were those $150 ones for then?.. Evaluation boards I think ? Wonder what Doc Martin would have to say;?... You lost me Him of Neve descent, didn't you work together once?.. DOC ? Martin ? I knew a Martin forget his surname who was in R&D. Not Martin (M.H) (Hartley) Jones PhD you mean ? He'd left by the time I arrived. I later did some work for him at Kelvin Hughes radar. Lovely chap. I still talk to him very occasionally. In fact I was just on the point of asking if he'd be happy to be a reference on my CV ! http://www.ibd-uk.com/members/jones-martin.htm Graham Yes thats the one, my next door neighbour. I thought he'd be retiring by now but he's as busy as ever:)... I'd expect he'd give U a reference;).. -- Tony Sayer |
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BTW I just paused as I heard that Winter is approaching. The geese are
flying over. So loud that I can hear them though the double-glazing. Nice sound, but sorry to wave farewell to summer... What summer was that then?.. Slainte, Jim -- Tony Sayer |
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In article , Anton Gÿsen
scribeth thus tony sayer wrote: In article , Anton Gÿsen scribeth thus tony sayer wrote: In article s.com, scribeth thus Jim Lesurf wrote: However if your audiolab seems to you not to clip or overheat I doubt you will have a problem with most other = 50Wpc amps in terms of power unless your speakers drop to low impedance. The 8000 series tends to have pokey small heatsinks[1], but can IIRC deliver reasonably high peak currents. Above said, I haven't yet seen you say anything that makes me feel you would benefit from a new amp. Except perhaps in the way of feeling pleased to own and use a newer and - allegedly - 'better' one. Well the phono sockets needed replacing 18 months ago - I'd like an amp with sockets which don't self destruct. Phileas Wonder if that was a poor batch none of mine are duff at all!... I believe it's a common problem with 8000As. Well I've got Four of them and their all fine;!... This site: http://www.theaudiocellar.co.uk/ specialises in, amongst other things, RCA socket replacements for Audiolab 8000As. I can't comment on 8000As because I have a new model 8000S. Interesting to see how the owners of those "Tractors" like to keep 'em going;). Funnily enough we've got four Band 1 transmitters , yes those frequencies are still used, and the cores in one have all disintegrated away whereas in the other their fine all about the same age!.. What is it that fails, the plastic moulding?.. I think so but I'm not sure. I've seen a couple on eBay which have been damaged in transit, so be careful if you ever move yours. -- Tony Sayer |
Amplifier power
In article , Eeyore rabbitsfriendsandrel
scribeth thus tony sayer wrote: Eeyore scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. Graham -- Tony Sayer |
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On Wed, 15 Oct 2008 19:06:26 +0100, Eeyore
wrote: Arny Krueger wrote: "tony sayer" wrote I Wonder how may pro recording bits of gear are around with 5532's;).. Tons and tons. But 5532s used right are really very good pieces, even by modern standards. And for the price...! And to think they were around in the 1970s too ! And Philips / Signetics initially only thought they were going to sell it into the telecoms market because of the 600 ohm drive ! Philips = NE5532 Signetics ( Philips N.A.) = SE5532 btw. The scarier part is how may pro recording bits of gear are around with TL074s, or even NJM4558s in the signal path. TL07Xs are still ok for some stuff, especially because of the jfet front end but 4558s ? YUCK ! Graham Well, since we're on the subject of IC's, I've dug out my little drawer of IC's left over from my 80's electronics days :-) Can't remember if any of these are op amps, but here are the numbers: LM382N LM380N LM3482A LM741 (pretty sure this is an op amp) M5K4164ANP (ain't a bloody clue what this is) TIP31A ZTX300 (a little 3 pin thing) ZN414 (this is an FM radio on a 3 pin chip) MJE2955 NE555P (loads of these buggers, I know they are timers). Sorry for hijacking this post ;-) Marky P. |
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tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus Did you check the spec of the LME49720 ? http://www.national.com/pf/LM/LME49720.html They had to devise a special method to measure the THD without the noise dominating. They're not even that shockingly expensive. Shockingly enough in small quantities;!... From the likes of Farnell maybe £4 seems a lot but compare that to a $400 woodenvolume control knob ! http://uk.farnell.com/1367613/semico...rs-integrated- circuits/product.us0?sku =national-semiconductor-lme49720ma-nopb&_requestid=131459 That's only £2 per divine op-amp ! What were those $150 ones for then?.. Evaluation boards I think ? Wonder what Doc Martin would have to say;?... You lost me Him of Neve descent, didn't you work together once?.. DOC ? Martin ? I knew a Martin forget his surname who was in R&D. Not Martin (M.H) (Hartley) Jones PhD you mean ? He'd left by the time I arrived. I later did some work for him at Kelvin Hughes radar. Lovely chap. I still talk to him very occasionally. In fact I was just on the point of asking if he'd be happy to be a reference on my CV ! http://www.ibd-uk.com/members/jones-martin.htm Yes thats the one, my next door neighbour. I thought he'd be retiring by now but he's as busy as ever:)... I don't think he wants to stop. And your neighbour too ! What a small world it is. I'd expect he'd give U a reference;).. I damn well hope so after I saved a project there ! Do you see him often ? Say Graham Stevenson sends his regards and let's see if it clicks. Graham |
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On Wed, 15 Oct 2008 20:58:29 +0100, tony sayer
wrote: In article , Eeyore rabbitsfriendsandrel scribeth thus tony sayer wrote: Eeyore scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. Graham What station's that then? Marky P. |
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tony sayer wrote: Eeyore scribeth thus Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. What's a community station ? :-( For me, radio is all but finished. Apart from Radio 4 of course. It's the same pap from every broadcaster. I can even recall several times changing channel and finding the very same track being played on the new one. Grrrrrrrr. Graham |
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Marky P wrote: Eeyore wrote: Arny Krueger wrote: "tony sayer" wrote I Wonder how may pro recording bits of gear are around with 5532's;).. Tons and tons. But 5532s used right are really very good pieces, even by modern standards. And for the price...! And to think they were around in the 1970s too ! And Philips / Signetics initially only thought they were going to sell it into the telecoms market because of the 600 ohm drive ! Philips = NE5532 Signetics ( Philips N.A.) = SE5532 btw. The scarier part is how may pro recording bits of gear are around with TL074s, or even NJM4558s in the signal path. TL07Xs are still ok for some stuff, especially because of the jfet front end but 4558s ? YUCK ! Graham Well, since we're on the subject of IC's, I've dug out my little drawer of IC's left over from my 80's electronics days :-) Can't remember if any of these are op amps, but here are the numbers: LM382N LM380N Maybe a crappy low power audio amp. LM3482A No idea about the above. LM741 (pretty sure this is an op amp) Pretty lousy one too by today's standards. M5K4164ANP (ain't a bloody clue what this is) Sounds like a Mostek part number. Does it have lots of legs ? TIP31A TO-220 medium power transistor. Forget which polarity. ZTX300 (a little 3 pin thing) Ferranti (now Zetex) small signal npn ? transistor. Their version (E-line) of TO-92. ZN414 (this is an FM radio on a 3 pin chip) For a TRF design. MJE2955 PNP complement of the 2N3055. TO-3 115W 60V device. NE555P (loads of these buggers, I know they are timers). They are. Single timers. Graham |
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In article , Eeyore rabbitsfriendsandrel
scribeth thus tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus tony sayer wrote: Eeyore scribeth thus Did you check the spec of the LME49720 ? http://www.national.com/pf/LM/LME49720.html They had to devise a special method to measure the THD without the noise dominating. They're not even that shockingly expensive. Shockingly enough in small quantities;!... From the likes of Farnell maybe £4 seems a lot but compare that to a $400 woodenvolume control knob ! http://uk.farnell.com/1367613/semico...rs-integrated- circuits/product.us0?sku =national-semiconductor-lme49720ma-nopb&_requestid=131459 That's only £2 per divine op-amp ! What were those $150 ones for then?.. Evaluation boards I think ? Wonder what Doc Martin would have to say;?... You lost me Him of Neve descent, didn't you work together once?.. DOC ? Martin ? I knew a Martin forget his surname who was in R&D. Not Martin (M.H) (Hartley) Jones PhD you mean ? He'd left by the time I arrived. I later did some work for him at Kelvin Hughes radar. Lovely chap. I still talk to him very occasionally. In fact I was just on the point of asking if he'd be happy to be a reference on my CV ! http://www.ibd-uk.com/members/jones-martin.htm Yes thats the one, my next door neighbour. I thought he'd be retiring by now but he's as busy as ever:)... I don't think he wants to stop. And your neighbour too ! What a small world it is. I'd expect he'd give U a reference;).. I damn well hope so after I saved a project there ! Do you see him often ? Say Graham Stevenson sends his regards and let's see if it clicks. Graham M8!, he's out running around 5 am 'ish and off to work before I fall downstairs and amble out to my office;!.. And gawd knows when he comes home either!, but if I do I will;).. -- Tony Sayer |
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In article , Marky P
scribeth thus On Wed, 15 Oct 2008 20:58:29 +0100, tony sayer wrote: In article , Eeyore rabbitsfriendsandrel scribeth thus tony sayer wrote: Eeyore scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. Graham What station's that then? http://www.209radio.co.uk Soon to have a new upgraded mixed polarisation aerial system to improve coverage:).. Pix on mb21 as soon as its done, with the newly refurbished one at Ely Cathedral.. Marky P. -- Tony Sayer Bancom Communications U.K. Tel+44 1223 566577 Fax+44 1223 566588 4 Wingate close, Cambridge, England, CB2 9HW E-Mail |
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In article , Eeyore rabbitsfriendsandrel
scribeth thus tony sayer wrote: Eeyore scribeth thus Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. What's a community station ? :-( For me, radio is all but finished. Apart from Radio 4 of course. It's the same pap from every broadcaster. I can even recall several times changing channel and finding the very same track being played on the new one. Grrrrrrrr. Its a version of small scale local radio with very public access to offer more locally focused programming. Some downright weird .. some wonderful:) Sunday's are excellent and "evening under lamplight" is as good as anything the BBC could produce.. But NO centralised playlists and no talking down to the listener like BBC local radio. Almost entirely staffed by volunteers.. http://www.209radio.co.uk/schedule/ Graham -- Tony Sayer |
Amplifier power
On Wed, 15 Oct 2008 23:11:16 +0100, Eeyore
wrote: Marky P wrote: Eeyore wrote: Arny Krueger wrote: "tony sayer" wrote I Wonder how may pro recording bits of gear are around with 5532's;).. Tons and tons. But 5532s used right are really very good pieces, even by modern standards. And for the price...! And to think they were around in the 1970s too ! And Philips / Signetics initially only thought they were going to sell it into the telecoms market because of the 600 ohm drive ! Philips = NE5532 Signetics ( Philips N.A.) = SE5532 btw. The scarier part is how may pro recording bits of gear are around with TL074s, or even NJM4558s in the signal path. TL07Xs are still ok for some stuff, especially because of the jfet front end but 4558s ? YUCK ! Graham Well, since we're on the subject of IC's, I've dug out my little drawer of IC's left over from my 80's electronics days :-) Can't remember if any of these are op amps, but here are the numbers: LM382N LM380N Maybe a crappy low power audio amp. LM3482A No idea about the above. LM741 (pretty sure this is an op amp) Pretty lousy one too by today's standards. M5K4164ANP (ain't a bloody clue what this is) Sounds like a Mostek part number. Does it have lots of legs ? Yep. 16. TIP31A TO-220 medium power transistor. Forget which polarity. ZTX300 (a little 3 pin thing) Ferranti (now Zetex) small signal npn ? transistor. Their version (E-line) of TO-92. ZN414 (this is an FM radio on a 3 pin chip) For a TRF design. MJE2955 PNP complement of the 2N3055. TO-3 115W 60V device. NE555P (loads of these buggers, I know they are timers). They are. Single timers. Graham Thanks for that! Now I've gotta decide whether to bin 'em or keep 'em for nostalga's sake :-) Marky P. |
Amplifier power
On Wed, 15 Oct 2008 23:04:45 +0100, Eeyore
wrote: tony sayer wrote: Eeyore scribeth thus Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. What's a community station ? :-( For me, radio is all but finished. Apart from Radio 4 of course. It's the same pap from every broadcaster. I can even recall several times changing channel and finding the very same track being played on the new one. Grrrrrrrr. Graham People used to slag off ILR radio in the past, but it's much worse now than it's ever been! Haven't listened in a long time (only for evaluation purposes). Marky P. |
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On Thu, 16 Oct 2008 08:55:57 +0100, tony sayer
wrote: In article , Marky P scribeth thus On Wed, 15 Oct 2008 20:58:29 +0100, tony sayer wrote: In article , Eeyore rabbitsfriendsandrel scribeth thus tony sayer wrote: Eeyore scribeth thus Robert Orban wrote: says... Seems to be tricky to find anything actually. This mic has a max input SPL of 134dB which receives the comment "Hi-SPL handling is perfect for suspension over choirs and orchestras" http://www.dv247.com/invt/11582/ Try this: Dynamic-Range Requirement for Subjectively Noise-Free Reproduction of Music JAES Volume 30 Issue 7/8 pp. 504-511; August 1982 A dynamic range of up to 118 dB is determined necessary for subjectively noise-free reproeuction of music in an audio recorder with a white-noise floor. Maximum peak sound-pressure levels in music are compared to the minimum discernible level of white noise in a quiet listening situation. Microphone noise limitations, monitoring loudspeaker capabilities, and performance environment noise levels are also considered. Author: Fielder, Louis D. Affiliation: Ampex Corporation, Redwood City, CA Well, I never imagined I'd have Bob Orban backing me up on a technical issue ! Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. Graham What station's that then? http://www.209radio.co.uk Soon to have a new upgraded mixed polarisation aerial system to improve coverage:).. Pix on mb21 as soon as its done, with the newly refurbished one at Ely Cathedral.. Marky P. Oh, of course. Should've known ;-) Marky P. |
Amplifier power
Marky P wrote: Eeyore wrote: Marky P wrote: M5K4164ANP (ain't a bloody clue what this is) Sounds like a Mostek part number. Does it have lots of legs ? Yep. 16. Ah ! 4164. That's ancient DRAM 64k x 1 IIRC. Graham |
Amplifier power
Marky P wrote: Eeyore wrote: Marky P wrote: ZN414 (this is an FM radio on a 3 pin chip) For a TRF design. IIRC I recall someone once asking for one of those sci.electronics.components. You could offer them on there rather than junk them. Graham |
Amplifier power
Marky P wrote: Eeyore wrote: tony sayer wrote: Eeyore scribeth thus Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. What's a community station ? :-( For me, radio is all but finished. Apart from Radio 4 of course. It's the same pap from every broadcaster. I can even recall several times changing channel and finding the very same track being played on the new one. Grrrrrrrr. People used to slag off ILR radio in the past, but it's much worse now than it's ever been! Haven't listened in a long time (only for evaluation purposes). BBC local radio is better ( three counties here ) but it's still sonic wallpaper. And the number of people who ring in about their cat / dog / hamster etc. Drives you up the wall. Graham |
Amplifier power
On Thu, 16 Oct 2008 14:02:20 +0100, Eeyore
wrote: Marky P wrote: Eeyore wrote: tony sayer wrote: Eeyore scribeth thus Thanks Bob ! Graham Him being the one who will be criticised on other groups for making DAB and FM ever more distorted;!... -- Tony Sayer You can't win 'em all ! No but theres a local station round these parts where the engineer does give a monkeys but the programme controller only knows LOUD LOUD and LOUDER!!! cos the bloke at the other station down the road is the same;; All thinking LOUD is better.. The local community station ****es over all of them for absolute sound quality:)).. What's a community station ? :-( For me, radio is all but finished. Apart from Radio 4 of course. It's the same pap from every broadcaster. I can even recall several times changing channel and finding the very same track being played on the new one. Grrrrrrrr. People used to slag off ILR radio in the past, but it's much worse now than it's ever been! Haven't listened in a long time (only for evaluation purposes). BBC local radio is better ( three counties here ) but it's still sonic wallpaper. And the number of people who ring in about their cat / dog / hamster etc. Drives you up the wall. Graham Three Counties here too (near St. Neots). Actually, I think BBC local radio has generally improved over the years. I prefer talk radio to music radio generally. Marky P. |
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