Nice hiccup from you as well, my dear chap, two posts on it,!
Yes, the upgraded power supply is allowing the Marantz to drive the nasty dip in the crossover impedance with more authority, better current delivery. With regard to the high end of the AR94, have you tidied up the crossover feeds to the treble driver? As in, completely hardwired, and a nice, fresh, blocking cap,
Frank, really? You bother to ask?
By now, you should have known that if I get my hands on it, it will leave me wired with Neotech pure silver cable throughout. So it was here.
However, when refreshing them, my key problem were the disappered foam bass and mid/bass surrounds. To my great pleasure, the guy charged with that has a very thick catalog of a German company manufacturing rubber surrounds, with a very comprehensive list of specfic loudspeakers, in which we found my very speakers. They were ordered, the price was very correct, and in two weeks, I had them on the drivers.
The Xovers were recapped with composite caps, i.e. using two or three caps in parallel to obtain the rerquired value, typicall mixing polycarbonate and polypropylene, while the wire wound resistors were replaced by Motorola's metal oxyde resistors of the71 and 72 series.
All of which helped to get what they were capable of.
On the motor drives I designed for Rockport I made them a current drive system. It addressed two problems. First the current waveform was low distortion even if the voltage was not. That would reduce the higher order harmonics in the drive. Second, it automatically compensated for the speed variations. On one version that had to drive from 16 RPM to 90 RPM (using a 2 speed motor) it worked great. I included the output transformer in the feedback loop (needed 120V nominal drive at least at startup) so the transformer was also compensated for. I used a 2 phase drive to manage the phase relationship at all the frequencies.
Those used an outer rotor hysteresis motor with induced poles. It was similar to Pabst motor and worked quite well. I gather they were expensive and I don't know if anyone makes an equivalent today.
The next gen Rockport used a much more complex direct drive system integrated with an air bearing. I think they cost around $20K ea. I don't think anyone made any money on that project.
One error in all that: The TD-160 platter was made of zinc alloy, not aluminum. Zinc has a density about twice that of aluminum; I don't know about the alloy used in the platter. (There is also the matter of generations, as MkII and later had, I think, a plastic inner platter.)
I got my brand new DL110 to put in the LP12. There is a nice circa 2 g weight to go with it which I will need. Wouldn't it be great if the TD145 killed it. In terms of accuracy it is very good. I read the DL110 is temperature compensated. That's some PU for the £138 I paid. I even got the Denon Japan 12 x DL110 carton. I will keep that.
Looking at silly solar maths. The most interesting fact about Mercury is the day is exactly 2/3 of a Mercury year ( 58.647 . 87.9705 Earth days ) . So it is a very weird planet. Maybe the divisor of the Earth year ( 365.2425 ) they speak of is Mercury year x 1 + 1/Pi. That is 87.97 x 1.31831 = 115.971721 . As Earth is 365.2425 that is 3.14941 or 1/4 % out. The spooky text says exact. Even 22/7 is only 0.04% out. If THD some might even say good enough.
Just for fun Venus has a day of 116.75 I believe? That is a better candidate. 3.1284 or 0.42 % out.
I did the Gregory–Leibniz series for fun . My phone is superb at these things. At +1/29 I gave up. Taking the average between -1/27 and +1/29 that is 0.7675 and 0.8020 in the sequence. When perfect both will be the same ( forever ) . Taking the mid point x 4 that is 3.139 or 0.083% out. Twice as bad as 22/7.
Looking at silly solar maths. The most interesting fact about Mercury is the day is exactly 2/3 of a Mercury year ( 58.647 . 87.9705 Earth days ) . So it is a very weird planet. Maybe the divisor of the Earth year ( 365.2425 ) they speak of is Mercury year x 1 + 1/Pi. That is 87.97 x 1.31831 = 115.971721 . As Earth is 365.2425 that is 3.14941 or 1/4 % out. The spooky text says exact. Even 22/7 is only 0.04% out. If THD some might even say good enough.
Just for fun Venus has a day of 116.75 I believe? That is a better candidate. 3.1284 or 0.42 % out.
I did the Gregory–Leibniz series for fun . My phone is superb at these things. At +1/29 I gave up. Taking the average between -1/27 and +1/29 that is 0.7675 and 0.8020 in the sequence. When perfect both will be the same ( forever ) . Taking the mid point x 4 that is 3.139 or 0.083% out. Twice as bad as 22/7.
Looking at the synchronous as an alternator I posted the other day it looks a tough nut to crack. The waveform it generates is almost triangular. And guess what, so are the slots. It might be stretching a point to say QED. It strikes me the window slots might be better shaped to assist? Happy to be wrong about that.
I took the point about motor core saturation. This is confirmed in the THD.
One idea suggested to me was motional feedback or better still negative output impedance. Seems what others are saying confirms it stands a chance.
The hysteresis type is already very good ( - 52 dB ). I have found putting it in the negative feedback loop helps greatly. It seems to do more than just control the output transformer. I found this by accident. No matter how much feedback I added the output transformer wasn't being compensated for as it should . Having built valve amps I know it should. Then I realized the motor was part of the feedback information. Makes me wonder what speakers really do?
I took the point about motor core saturation. This is confirmed in the THD.
One idea suggested to me was motional feedback or better still negative output impedance. Seems what others are saying confirms it stands a chance.
The hysteresis type is already very good ( - 52 dB ). I have found putting it in the negative feedback loop helps greatly. It seems to do more than just control the output transformer. I found this by accident. No matter how much feedback I added the output transformer wasn't being compensated for as it should . Having built valve amps I know it should. Then I realized the motor was part of the feedback information. Makes me wonder what speakers really do?
My apologies,
... my thoughts were in the wrong zone at that moment !! But, I am interested in the significance of the driver characteristics here - I can't recall, do you take warming up of the drivers into consideration? I bumped into the local enthusiast just the other day, and he's set up a new, lower cost system in an outside shed ... unprompted, he mentioned that the "lesser" speakers require far more "hammering" to get them into a good zone, a few hours in fact, at normal volumes ...
IOW, if you drive the AR's hard, really hard for an extended time, does that significantly alter the apparent behaviours?
Well, as you can imagine, once I'm up, showered and ready to start the day, I do need my morning coffee, or my slew rate goes assymetrical. Then wife goes to work, la-la-la, and before you know it, it's past 10 AM. Since I always get up 7:30-8:00, and since my first semi-concious act of the day is to switch the sound on, by then it has been working for at least 2 hours.
So, even if I'm allmeasurements that day, before I can even start, it's been ON for at least 2 hours. Quite enough for everything to reach it's normal operating temperature. Since I'm not deaf (yet), I do not need to cook it at some unrealistic temperature which it would not normally ever have.
So, even if I'm allmeasurements that day, before I can even start, it's been ON for at least 2 hours. Quite enough for everything to reach it's normal operating temperature. Since I'm not deaf (yet), I do not need to cook it at some unrealistic temperature which it would not normally ever have.
Thanks you folks. Was just trying to guess that if platter coast down time is good enough to negate the minor speed variations. There ought to be best platter weight/motor/bearing combination so as it needs least intervention of controller.
A little different topic. I did a stylus-groove drawing to see how much difference a parallel tracking and pivot arm makes regarding stylus tip touching both groove walls. I put in approximate figures of 213 mm pivot to spindle length, 20 degree offset and 220 mm pivot to stylus length. made a 40 µm groove. And a circle to represnt stylus. If placed on outermost groove both side of the groove wall touches the stylus perpendicularly. When moved to inner most groove to calculate the deviation it makes to both groove walls it came about 20 µm. So how much difference this will make to stereo information/phase difference(if mono)/tracking error (Sorry for bad graphics)
Regards
Would that be 701 ?
A little different topic. I did a stylus-groove drawing to see how much difference a parallel tracking and pivot arm makes regarding stylus tip touching both groove walls. I put in approximate figures of 213 mm pivot to spindle length, 20 degree offset and 220 mm pivot to stylus length. made a 40 µm groove. And a circle to represnt stylus. If placed on outermost groove both side of the groove wall touches the stylus perpendicularly. When moved to inner most groove to calculate the deviation it makes to both groove walls it came about 20 µm. So how much difference this will make to stereo information/phase difference(if mono)/tracking error (Sorry for bad graphics)
Regards
Attachments
Still not getting the answer I'm after,
. If I was tasked to assess that speaker, I would use a particularly testing recording, say 5 minutes from a cold start for the speaker. Then I would let it simmer nicely for an hour or two as you have done, and assess again. Finally, I would hammer them for an hour or so with high energy R&R, say, and then try that testing recording again. That would give me a pretty decent handle on whether conditioning was relevant or not ... Just started using my new computer in Windows 8. What a daft system. I wanted to use XP. It wasn't compatible with the motherboard etc. The idea is to have a spare. The old one will be reconfigured in XP and have as many tasks removed to give it an easier life. XP would run all my old Windows 3.1 programs even. I have an emulator called DOS BOX 0.74 that does that now. Fire Fox is now Water Fox . Works the same so happy with that. I have the old Solitaire in DOS BOX . The game Windows used to teach mouse control.
What makes this peculiar is have used Mac and Linux without having to learn it ( borrowed them ). Windows 8 should be 99% as any windows. It is the most different of all.
On a positive note the graphs card and DAC are sensible cheap devices. Wow my photographs look good. If the DAC is half as good I will be happy. Maybe I should get a Freeware analyzer program and compare with my real ones. The computer cost £180 in parts using a recycled high grade PSU. It is almost silent in use.
Talking of tracking on turntables . The mass loaded Denon DL110 tracking 2g Shure and 1.83g Electronic ( yep, trust Shure myself ). Has the best tracking I ever met. If the Thorens arm helps I don't know? Turntable designers often speak nicely of gimble bearings . Maybe it helps. Maybe Thorens were not stupid ??? Also the suggestion it is broadcast type sound seems correct and correct is the best word for it. How it can get the old dog Quad 33 to work defeats me . It's 45 kHz response should cause all sorts of trouble, and yet it doesn't. The Quad has a very steep 20 Hz filter years before the 7950 uS suggestion. As the Thorens and LP12 have a reputation for enhanced 25 Hz that may be synergistic? Quad was often used with Garrard or TD150 so it makes sense. The ESL couldn't handle sub 30Hz bass and make no music from it. The SMGa also.
There was a French mat called Audio Ref Le Mat . It was designed for the TD160 and used measurements like Denon used to look at resonance ( looks to me they copied Denon ). Also the various cork-neoprene mats work.
A friend asked about cheap RIAA for his parents. Chinese kit for $25. It looks to be OK. Uses NE5532 and has chip holders. James can try a few. They make a posh version with AD797. My instinct is MC33078 as I like them. It has a gain of 36 dB. I will add gain options using shunt resistors. 50 dB to suit DL110. I suspect passive75 uS active 3180/318. Hope so. It should beat the Quad by a mile. Not least I have a very nice ready made PSU for it ( 1000 in fact ). If it is pleasing I will let you know. If only to feed the sound card it might save work. I recently built similar on strip-board. Absolutely no problems at all. Gain of 10 000 at 20 Hz. I brought everything to one ground point and built the circuit exactly as circuit diagram.
What makes this peculiar is have used Mac and Linux without having to learn it ( borrowed them ). Windows 8 should be 99% as any windows. It is the most different of all.
On a positive note the graphs card and DAC are sensible cheap devices. Wow my photographs look good. If the DAC is half as good I will be happy. Maybe I should get a Freeware analyzer program and compare with my real ones. The computer cost £180 in parts using a recycled high grade PSU. It is almost silent in use.
Talking of tracking on turntables . The mass loaded Denon DL110 tracking 2g Shure and 1.83g Electronic ( yep, trust Shure myself ). Has the best tracking I ever met. If the Thorens arm helps I don't know? Turntable designers often speak nicely of gimble bearings . Maybe it helps. Maybe Thorens were not stupid ??? Also the suggestion it is broadcast type sound seems correct and correct is the best word for it. How it can get the old dog Quad 33 to work defeats me . It's 45 kHz response should cause all sorts of trouble, and yet it doesn't. The Quad has a very steep 20 Hz filter years before the 7950 uS suggestion. As the Thorens and LP12 have a reputation for enhanced 25 Hz that may be synergistic? Quad was often used with Garrard or TD150 so it makes sense. The ESL couldn't handle sub 30Hz bass and make no music from it. The SMGa also.
There was a French mat called Audio Ref Le Mat . It was designed for the TD160 and used measurements like Denon used to look at resonance ( looks to me they copied Denon ). Also the various cork-neoprene mats work.
A friend asked about cheap RIAA for his parents. Chinese kit for $25. It looks to be OK. Uses NE5532 and has chip holders. James can try a few. They make a posh version with AD797. My instinct is MC33078 as I like them. It has a gain of 36 dB. I will add gain options using shunt resistors. 50 dB to suit DL110. I suspect passive75 uS active 3180/318. Hope so. It should beat the Quad by a mile. Not least I have a very nice ready made PSU for it ( 1000 in fact ). If it is pleasing I will let you know. If only to feed the sound card it might save work. I recently built similar on strip-board. Absolutely no problems at all. Gain of 10 000 at 20 Hz. I brought everything to one ground point and built the circuit exactly as circuit diagram.
Tracking error. Elite ( Max Townsend ) used to do a very nice gauge that allowed the distortion to be calculated in the simplest way . It was very interesting to see the result of changing the complete geometry with a different offset ( about 2 degrees ). It was possible to average the distortion so as to never reach the zero points but be lower at the end of sides. I think it did sound better.
The big problem with this is my friend uses binocular magnifiers so as to find even the simplest zeros, Then the question has to be is everything square. Next is the cartridge set accurately in the coils. The old 63.5 + 119 mm zero points were from the 1920's 78's . Percy Wilson who's house I pass going to the cinema ( Phoenix Walton Street Oxford , Him Plantation Road ) won a competition in I guess 1927 when new electric pick ups were being fitted to turntables. To this day arms are set around these points more than most realize .
Frank Schroeder who has made a study of this chooses 66 and 120.9 mm.
Most parallel tracking arms I have used are disappointing. I don't know what I expected. I certainly didn't hear anything very different. I think often the extra engineering brings new problems. For what it is worth a uni-pivot of good design sounds more like what I expected. Good uni-pivots show what some call trailing edge detail. If very well designed they don't loose the leading edge. Why I have been so impressed with the Thorens TIP 16 is it sound very like a uni-pivot. As it was made in numbers lets hope mine isn't a better sample of mostly a bad design. In it's day it was usually junked ASAP. The conceptual engineers hated it. As far as I can see an arm needs to be a torsion bar for a Formula one car in their eyes. The high prices for Ortofon arms begs the question. Why was the Ortofon junk in the past and now??? The TP16 looks no worse if the head-shell is slightly forgiven.
And now the easy way.
http://www.audiomods.co.uk/papers/baerwald.pdf
The big problem with this is my friend uses binocular magnifiers so as to find even the simplest zeros, Then the question has to be is everything square. Next is the cartridge set accurately in the coils. The old 63.5 + 119 mm zero points were from the 1920's 78's . Percy Wilson who's house I pass going to the cinema ( Phoenix Walton Street Oxford , Him Plantation Road ) won a competition in I guess 1927 when new electric pick ups were being fitted to turntables. To this day arms are set around these points more than most realize .
Frank Schroeder who has made a study of this chooses 66 and 120.9 mm.
Most parallel tracking arms I have used are disappointing. I don't know what I expected. I certainly didn't hear anything very different. I think often the extra engineering brings new problems. For what it is worth a uni-pivot of good design sounds more like what I expected. Good uni-pivots show what some call trailing edge detail. If very well designed they don't loose the leading edge. Why I have been so impressed with the Thorens TIP 16 is it sound very like a uni-pivot. As it was made in numbers lets hope mine isn't a better sample of mostly a bad design. In it's day it was usually junked ASAP. The conceptual engineers hated it. As far as I can see an arm needs to be a torsion bar for a Formula one car in their eyes. The high prices for Ortofon arms begs the question. Why was the Ortofon junk in the past and now??? The TP16 looks no worse if the head-shell is slightly forgiven.
And now the easy way.
http://www.audiomods.co.uk/papers/baerwald.pdf
July 2003 Trading Tips Newsletter
More curious solar system maths ( trading is last part ). I guess harmony of motion would dictate some of this? It is interesting how 1.618 and 3.142 come into things. Probably more unusual if they didn't ? The spiral and circle are seen everywhere in nature.
I asked myself a question I never asked before. How large is a sphere that sits inside a cubic box? I would have assumed 67% roughly . It is 52.36 % . Although the ancient world was fascinated about circles inside and outside of squares there seems no great interest in spheres inside cubic boxes.
People in the packing industry are very interested and the maths exists for spheres with small spheres . The maths really says the boxes we use already are the best solution.
More curious solar system maths ( trading is last part ). I guess harmony of motion would dictate some of this? It is interesting how 1.618 and 3.142 come into things. Probably more unusual if they didn't ? The spiral and circle are seen everywhere in nature.
I asked myself a question I never asked before. How large is a sphere that sits inside a cubic box? I would have assumed 67% roughly . It is 52.36 % . Although the ancient world was fascinated about circles inside and outside of squares there seems no great interest in spheres inside cubic boxes.
People in the packing industry are very interested and the maths exists for spheres with small spheres . The maths really says the boxes we use already are the best solution.
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Nigel, I think you will enjoy reading this:
https://ia700307.us.archive.org/31/items/worksofarchimede029517mbp/worksofarchimede029517mbp.pdf
George
https://ia700307.us.archive.org/31/items/worksofarchimede029517mbp/worksofarchimede029517mbp.pdf
George
I think you must have read my mind. It will be printed . I will indeed enjoy it.
LP12 shoot out in the morning ( cartridge will need running in ). I read that the LP12 Ekos as now costs about the same as a tiny house for restoration in Limoges France. I even more want the TD145 (TD160) to beat it because of that. Mine is not bang up to date but 100 % perfect of it's type. Tony from Linn tried to sell me the update bits. I said no thanks as I could make them myself in an afternoon. He looked dumfounded and couldn't move. The timing difference as Linn call it was obvious. Still not a top draw turntable to me. Lets be fair the Quad might be the leveler. All the same. A Garrard 401 later serial number I feel outperforms a LP12 of the latest type. I have a hunch a sorted out Lenco also. The Lenco has better timing!
Here is a thing . An underpowered turntable will play the record at exactly the same average speed as the same turntable correctly powered. The difference is the start of the leading edge is wrong and the peak of the wave is with a wobble. If we think a bit this means these areas of performance must be universally important. That is wave 0 and maximum points. Perhaps the ear does exactly what the digital output filtering does and joins the dots. Possibly all the music we hear is constructed from these datum points? Get them slightly wrong and the illusion is lost. Thus vinyl with all of it's errors is forgiven because in the more ideal types the timing errors are not too great. This might go some way to explain why harmonic distortion in reality is not too critical.
Thanks George.
6/Pi is Cube to Sphere. It is nicely obvious I guess? That goes for surface and volume.
LP12 shoot out in the morning ( cartridge will need running in ). I read that the LP12 Ekos as now costs about the same as a tiny house for restoration in Limoges France. I even more want the TD145 (TD160) to beat it because of that. Mine is not bang up to date but 100 % perfect of it's type. Tony from Linn tried to sell me the update bits. I said no thanks as I could make them myself in an afternoon. He looked dumfounded and couldn't move. The timing difference as Linn call it was obvious. Still not a top draw turntable to me. Lets be fair the Quad might be the leveler. All the same. A Garrard 401 later serial number I feel outperforms a LP12 of the latest type. I have a hunch a sorted out Lenco also. The Lenco has better timing!
Here is a thing . An underpowered turntable will play the record at exactly the same average speed as the same turntable correctly powered. The difference is the start of the leading edge is wrong and the peak of the wave is with a wobble. If we think a bit this means these areas of performance must be universally important. That is wave 0 and maximum points. Perhaps the ear does exactly what the digital output filtering does and joins the dots. Possibly all the music we hear is constructed from these datum points? Get them slightly wrong and the illusion is lost. Thus vinyl with all of it's errors is forgiven because in the more ideal types the timing errors are not too great. This might go some way to explain why harmonic distortion in reality is not too critical.
Thanks George.
6/Pi is Cube to Sphere. It is nicely obvious I guess? That goes for surface and volume.
GORGEOUS ARISTON RD11 model E - RARE!! | eBay
Here is why Linn succeeded. As the first 50 RD11 were LP12's is is hard to see how Ariston could get it so wrong. Ugly and illogical. Note how the bracing bar is missing from the sub chassis ( and cross brace ) . £2 saved? The TD 145 also is nicer. This RD11 is like the most horrible motorcars of the time. I had no idea they were this bad. The bearing looks totally different. The RD 80 was fine and much cheaper. The strange thing is the production engineering for this awful machine would have been expensive. The LP12 was cheap because it is just wood and metal plate. How stupid to spend money to get it this bad. Each RD 80 I put together was badly made. It didn't matter as I just did the same as a LP12 and then it was nice. Linn threw them together in 15 minutes and used dedicated dealers to do the 4 hours they needed. Not a problem except I fell for it and felt important. The difference is Ariston said no need to set them up as it's ready to play. My eye it was. To be clear the LP 12 was of 100 % inspected parts. Training the dealers to finish them was some mind control.
A RD 80. Look how nice it is.
https://www.youtube.com/watch?v=j1GYDy1s9GE
A later RD 11 looks OK. I still think RD 80 better as it is more like the LP12 original.
https://www.youtube.com/watch?v=6RCh0FgmcsY
Here is why Linn succeeded. As the first 50 RD11 were LP12's is is hard to see how Ariston could get it so wrong. Ugly and illogical. Note how the bracing bar is missing from the sub chassis ( and cross brace ) . £2 saved? The TD 145 also is nicer. This RD11 is like the most horrible motorcars of the time. I had no idea they were this bad. The bearing looks totally different. The RD 80 was fine and much cheaper. The strange thing is the production engineering for this awful machine would have been expensive. The LP12 was cheap because it is just wood and metal plate. How stupid to spend money to get it this bad. Each RD 80 I put together was badly made. It didn't matter as I just did the same as a LP12 and then it was nice. Linn threw them together in 15 minutes and used dedicated dealers to do the 4 hours they needed. Not a problem except I fell for it and felt important. The difference is Ariston said no need to set them up as it's ready to play. My eye it was. To be clear the LP 12 was of 100 % inspected parts. Training the dealers to finish them was some mind control.
A RD 80. Look how nice it is.
https://www.youtube.com/watch?v=j1GYDy1s9GE
A later RD 11 looks OK. I still think RD 80 better as it is more like the LP12 original.
https://www.youtube.com/watch?v=6RCh0FgmcsY
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I will have to revise and revisit this. I have found, since this posting, that the 40th Anniversary releases are done by Steve Wilson, who also did the recent King Crimson and EL&P; rather than Peter Mew, like the This Was Collector's Edition. There are several available. I have a feeling those reviews that got me more or less ignoring that TaaB are probably from those that like what Mew had done. I am now awaiting shipment of several additional copies of Tull albums, and based on the EL&P and King Crimson work, suspect that Wilson's redo of Benefit and A Passion Play will be to die for. If so, I will be praying that he wants to take a look at Songs From The Wood, at some pointThe recent one with the DVD size case and extras, isn't it? I read less than stellar reviews, and decided to skip it.
And, from the, "source," as it were: "“I have to make my judgments based on selling as many records as possible. That’s my brief. So even though there might be audiophiles who say you shouldn’t do this, well, I’m sorry, audiophiles, you’re a very small part of the market.”"
TIL...
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A lot of the "answers" as to why some playback is "magic" and other, nominally "better" setups are a dead loss, are in there. The brain is joining a lot of the dots, but if the dots are too confusing, then it gives up, and rejects the sound as "unworthy". So, make sure the dots come out in a way that suits the brain, and you'll be way in front ...
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