| Page 2 of 2 | 1 | 2 |
|
|
|
No wonder people can't hear the difference...
"Rob" wrote in message
... How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? What would cleaning a dirty plug do to the sound? You are confusing mains power connectors with audio interconnects, it was the later about which Graham referred to cleaning the plug. Poor contact on audio interconnects (and on switches carrying audio) can adversely affect sound quality. David. |
No wonder people can't hear the difference...
"Phil Allison" wrote in message
... "David Looser" Indeed, unlike the 405 in which the TL071 op-amp is in the signal path. ** The original Quad 405 used LM301A op-amps. http://www.geocities.com/quad_esl63/...c/power405.jpg Well OK, but it was changed to a TL071 in later production. The TL071 did not exist when it was designed. So when was the 405 designed?, and when was the TL071 launched? I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, and I've got an early production 44 control amp which is full of TL071s. David. |
No wonder people can't hear the difference...
David Looser wrote:
"Phil Allison" wrote in message ... "David Looser" Indeed, unlike the 405 in which the TL071 op-amp is in the signal path. ** The original Quad 405 used LM301A op-amps. http://www.geocities.com/quad_esl63/...c/power405.jpg Well OK, but it was changed to a TL071 in later production. The TL071 did not exist when it was designed. So when was the 405 designed?, and when was the TL071 launched? I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, and I've got an early production 44 control amp which is full of TL071s. David. 405 released 1975 - ceased 1982 64,000 units 405-2 released 1982 - ceased 1993 100,000 units 44 released 1979 ceased 1989 40,000 units I have no idea when the TL071 surfaced but it would have to be mid to late 1970's. |
No wonder people can't hear the difference...
Rob wrote: Eeyore wrote: " wrote: Yet in a high resolution system, power cables.......can make a difference. Compared to wet string maybe. Otherwise a properly rated power cord willl have ZERO difference. Have you ANY IDEA how the AC mains gets mangled to produce the DC for an amplifier ? The possibility of some ultra-linear power cord affecting it is beyond laughable. And I DESIGN this stuff btw, so I DO know what I'm talking about. In great detail. How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? What would cleaning a dirty plug do to the sound? Remove potentially rectifying oxides. Also re-tighten the connection, making it more secure / less electrical resistance. Graham |
No wonder people can't hear the difference...
David Looser wrote: "Phil Allison" wrote in message "David Looser" Indeed, unlike the 405 in which the TL071 op-amp is in the signal path. ** The original Quad 405 used LM301A op-amps. http://www.geocities.com/quad_esl63/...c/power405.jpg Well OK, but it was changed to a TL071 in later production. The TL071 did not exist when it was designed. So when was the 405 designed?, and when was the TL071 launched? I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, and I've got an early production 44 control amp which is full of TL071s. There's a few years in it IIRC. Graham |
No wonder people can't hear the difference...
"Eeyore" wrote in message
... David Looser wrote: So when was the 405 designed?, and when was the TL071 launched? I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, and I've got an early production 44 control amp which is full of TL071s. There's a few years in it IIRC. I can't remember exactly when I first encountered the TL071/2/4, but I was certainly designing around them in the second half of the 1970s, so there can't have been that many years between them. David. |
No wonder people can't hear the difference...
"David Tosser" "Phil Allison" Indeed, unlike the 405 in which the TL071 op-amp is in the signal path. ** The original Quad 405 used LM301A op-amps. http://www.geocities.com/quad_esl63/...c/power405.jpg Well OK, but it was changed to a TL071 in later production. The TL071 did not exist when it was designed. So when was the 405 designed?, ** Prior to 1975. and when was the TL071 launched? ** July 1977. ...... Phil |
No wonder people can't hear the difference...
David Looser wrote: "Eeyore" wrote in message David Looser wrote: So when was the 405 designed?, and when was the TL071 launched? I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, and I've got an early production 44 control amp which is full of TL071s. There's a few years in it IIRC. I can't remember exactly when I first encountered the TL071/2/4, but I was certainly designing around them in the second half of the 1970s, so there can't have been that many years between them. My 1980 copy of the Bifet Design Manual dates the TL080 data sheet as Feb 77 and TL070 as Sep 78 FWIW. Graham |
No wonder people can't hear the difference...
"David Tosser" I was using TL071s (and TL072 and TL074 dual and quad versions) in the mid seventies, ** Not until after July 1977 you were not. " While there are definite limits on human intelligence - there is no limit to human stupidity. " As D. Tosser continually proves. ...... Phil |
No wonder people can't hear the difference...
Eeyore wrote:
Rob wrote: Eeyore wrote: " wrote: Yet in a high resolution system, power cables.......can make a difference. Compared to wet string maybe. Otherwise a properly rated power cord willl have ZERO difference. Have you ANY IDEA how the AC mains gets mangled to produce the DC for an amplifier ? The possibility of some ultra-linear power cord affecting it is beyond laughable. And I DESIGN this stuff btw, so I DO know what I'm talking about. In great detail. How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? I take it you don't mean mains plugs - they can be as grubby as you like? Your post at midnight above seems to refer to mains and audio. What would cleaning a dirty plug do to the sound? Remove potentially rectifying oxides. Also re-tighten the connection, making it more secure / less electrical resistance. I was clearing out the last of the accumulated rubbish following a move the other day, and came across some 'Goldring Magic Contact Cleaning Fluid' - a bit of a faff involving two liquids and pipe cleaners. In view of the fact I haven't cleaned a lead since buying it (20 odd years ago) I might as well use it up - although i'd assume normal contact cleaner or isopropanol alcohol would be just as good? Rob |
No wonder people can't hear the difference...
Phil Allison wrote:
"Rob" Eeyore wrote: Not to memntion that changing the lead would 'clean' the contacts in the process which could easily have an effect. How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? ** How about you make sure to post UNDER any words you are referring o - instead of creating a false para- phrased version of your own. What would cleaning a dirty plug do to the sound? ** Not what was previously written - is it ? Dickhead. Potty mouth. |
No wonder people can't hear the difference...
David Looser wrote:
"Rob" wrote in message ... How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? What would cleaning a dirty plug do to the sound? You are confusing mains power connectors with audio interconnects, it was the later about which Graham referred to cleaning the plug. Poor contact on audio interconnects (and on switches carrying audio) can adversely affect sound quality. Yes, I gather, thanks. Rob |
No wonder people can't hear the difference...
On 2008-07-30, Jim Lesurf wrote:
On 30 Jul, wrote: In article , wrote: I recently changed the IC's in a Quad 306 power amplifier (TI's to Burr-Browns) playing through some Quad 988s. My wife (not an audiophile), walked in the room and immediately asked what had changed... "it sounded more alive" was her comment. Comment much as above. It is a common experience that what we hear 'changes' from one situation to another. Afraid that simply isn't a basis for deciding *why* a 'change' was heard. Far too many other possible causes or reasons which your simple anecdote fails to deal with. BTW I just looked at my copy of the 306 diagram. If you are referring to 'IC1' (TLC271) then you might like to note that IIUC its role seems to be to null the dc offset of the amp. The 2M2 resistor (r33) and 680nF cap (c3) mean it only really does much around the 1 Hz region and below. You loudspeakers (and wife) are remarkable if they can hear this. ... Even if a recording had content in the subsonic frequency range capable of "fooling" the R33/C3 integrator, the input HPF formed by C2 (100 nF) and R6 (120 kOhms) has a time constant that is about 125 times smaller. So that subsonic content would suffer at least 7 octaves worth of attenuation just in the 306 input stage. That's before even mentioning Fletcher and Munson. -- John Phillips |
No wonder people can't hear the difference...
Have a look at this if you like contentious stuff.
http://www.diyaudio.com/forums/showt...hreadid=111973 I'm not interested in any of this myself, but thought it might appeal to others who like arguing. Andy |
No wonder people can't hear the difference...
Rob wrote: Eeyore wrote: Rob wrote: Eeyore wrote: " wrote: Yet in a high resolution system, power cables.......can make a difference. Compared to wet string maybe. Otherwise a properly rated power cord willl have ZERO difference. Have you ANY IDEA how the AC mains gets mangled to produce the DC for an amplifier ? The possibility of some ultra-linear power cord affecting it is beyond laughable. And I DESIGN this stuff btw, so I DO know what I'm talking about. In great detail. How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? I take it you don't mean mains plugs You are correct in your interpretation. - they can be as grubby as you like? Your post at midnight above seems to refer to mains and audio. What would cleaning a dirty plug do to the sound? Remove potentially rectifying oxides. Also re-tighten the connection, making it more secure / less electrical resistance. I was clearing out the last of the accumulated rubbish following a move the other day, and came across some 'Goldring Magic Contact Cleaning Fluid' - a bit of a faff involving two liquids and pipe cleaners. In view of the fact I haven't cleaned a lead since buying it (20 odd years ago) I might as well use it up - although i'd assume normal contact cleaner or isopropanol alcohol would be just as good? Isopropyl will remove greases but not much else AFAIK. God only knows what's in 'contact cleaner'. I try and avoid the stuff. Graham |
No wonder people can't hear the difference...
Andy Evans wrote: Have a look at this if you like contentious stuff. http://www.diyaudio.com/forums/showt...hreadid=111973 I'm not interested in any of this myself, but thought it might appeal to others who like arguing. Since loudspealers aren't 8R2 resistors, the different results surprises me not one jot. Hence the initial assumption is incorrect. Graham |
No wonder people can't hear the difference...
Eeyore wrote:
Rob wrote: Eeyore wrote: Rob wrote: Eeyore wrote: " wrote: Yet in a high resolution system, power cables.......can make a difference. Compared to wet string maybe. Otherwise a properly rated power cord willl have ZERO difference. Have you ANY IDEA how the AC mains gets mangled to produce the DC for an amplifier ? The possibility of some ultra-linear power cord affecting it is beyond laughable. And I DESIGN this stuff btw, so I DO know what I'm talking about. In great detail. How do you reconcile this 'no difference' claim with your notion that a clean plug can affect sound? I take it you don't mean mains plugs You are correct in your interpretation. - they can be as grubby as you like? Your post at midnight above seems to refer to mains and audio. What would cleaning a dirty plug do to the sound? Remove potentially rectifying oxides. Also re-tighten the connection, making it more secure / less electrical resistance. I was clearing out the last of the accumulated rubbish following a move the other day, and came across some 'Goldring Magic Contact Cleaning Fluid' - a bit of a faff involving two liquids and pipe cleaners. In view of the fact I haven't cleaned a lead since buying it (20 odd years ago) I might as well use it up - although i'd assume normal contact cleaner or isopropanol alcohol would be just as good? Isopropyl will remove greases but not much else AFAIK. God only knows what's in 'contact cleaner'. I try and avoid the stuff. Graham So it's an 'oxide remover' that's needed? Then, I suppose it depends on the oxide, and gold is less likely to oxidise than other things, so it's more muck removal? I'd guess you use, or would use if forced, Brasso or somesuch? No idea what's in the Goldring stuff, or indeed this: http://www.cybermarket.co.uk/shopscr1655.html which seems to work on switches, in the sense they don't crackle after use - although the effect doesn't last forever, which might be related to why you don't use it. Anyway, I'll keep a look out. Rob |
No wonder people can't hear the difference...
Rob wrote: Eeyore wrote: Rob wrote: Eeyore wrote: Rob wrote: What would cleaning a dirty plug do to the sound? Remove potentially rectifying oxides. Also re-tighten the connection, making it more secure / less electrical resistance. I was clearing out the last of the accumulated rubbish following a move the other day, and came across some 'Goldring Magic Contact Cleaning Fluid' - a bit of a faff involving two liquids and pipe cleaners. In view of the fact I haven't cleaned a lead since buying it (20 odd years ago) I might as well use it up - although i'd assume normal contact cleaner or isopropanol alcohol would be just as good? Isopropyl will remove greases but not much else AFAIK. God only knows what's in 'contact cleaner'. I try and avoid the stuff. So it's an 'oxide remover' that's needed? And general muck and dust remover. A clean cloth can be very effective. Then, I suppose it depends on the oxide, and gold is less likely to oxidise than other things, I believe gold should not oxidise in normal domestic use. A 'proper' decent thickness of gold plating that is. so it's more muck removal? I'd guess you use, or would use if forced, Brasso or some such? Used to use Brasso to clean studio patch cords which were once unplated brass. No idea what's in the Goldring stuff, or indeed this: http://www.cybermarket.co.uk/shopscr1655.html which seems to work on switches, in the sense they don't crackle after use - although the effect doesn't last forever, which might be related to why you don't use it. Indeed. Tends to be a temp fix only. Graham |
No wonder people can't hear the difference...
Eiron wrote:
This one? A56AK http://www.maplin.co.uk/Module.aspx?...34128&doy=28m7 Yup, that's the beast! Was £2 cheaper in store... -- Squirrel Solutions Ltd Tel: (01453) 845735 http://www.squirrelsolutions.co.uk/ Fax: (01453) 843773 Registered in England: 05877408 |
No wonder people can't hear the difference...
"Glenn Richards" wrote in message
. uk... Eiron wrote: This one? A56AK http://www.maplin.co.uk/Module.aspx?...34128&doy=28m7 Yup, that's the beast! Was £2 cheaper in store... Thanks for pointing me in that direction. I bought one, not that I'm too bothered about "bit perfection" for the application, but I needed an SPDIF output from a laptop, and that seemed the easiest and cheapest way. Unfortunately I needed a co-ax output rather than an optical one, but a 74HCU04, a couple of resistors and a phono socket sorted that. David. |
No wonder people can't hear the difference...
"Bob Latham" wrote in message
... In article , David Looser wrote: [Snip] Unfortunately I needed a co-ax output rather than an optical one, but a 74HCU04, a couple of resistors and a phono socket sorted that. Could you point me at any info on that please? The logic-level SPDIF signal, as present at the drive pin of the optical transmitter, is buffered by one section of the 74HCU04. The output of that section drives three other sections in parallel. The outputs of those sections are connected, via individual 1K resistors, to the output phono socket. A 100 ohm resistor is connected across the output socket. The chip (DIL) is mounted on a tiny off-cut of double-sided veroboard (groundplane on the top). A 100nF X7R ceramic capacitor is connected as physically close as possible between the chip's power pin and the groundplane. OK, that's actually 2 resistors and one ceramic capacitor more than I said above. Hope that helps David. |
| All times are GMT. The time now is 08:18 AM. |
|
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.0.0
Copyright ©2004-2006 AudioBanter.co.uk