Love the 19th century look, I have a couple of Weston voltmeters where the patent numbers don't go past 1900.
The older I get the more I follow the following
1. I'm probably imagining it
2. I have too much music to enjoy to worry about trying to do a controlled test.
Last 'OMG' moment I had was 1989 when I replaced a NAD power amp with a radford STA25. They really did sound different. Maybe one day I will sweat the differences again but for now just loving the music is so much more enjoyable.
And I can understand a 'house sound'. Certain companies have a house sound, but I still am not sure that below an (argued) threshold you could tell the difference between topologies.
Well, from humans on our planet to Suns in the galaxies, and galaxies themselves, no object has his exact twin in the universe.
Who is the believer in numbers, reflecting the perfect accuracy of our technology ?
We try our best to simplify, with our limited mind, but no perfect sphere or even strait line in the universe.
If we have to stay modest about what we know for now of the universe (<20% ?), what about what we try to build with this very limited knowledge ?
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Thanks. Even though there is some sand under the hood (what look like tubes are actually transformers), I put a great deal of effort into keeping everything else as authentic as possible.
The top plate is ebonite (hard rubber) which was the commonly used material back in the '20s. Near impossible to find in sheet form, but eventually found a little place in Tokyo that has been producing ebonite since the '50s that is still making it in sheets.
The binding posts were the toughest nut to crack. I fell in love with them after seeing them on an old Western Electric 7A amplifier from 1924. But after a thorough Google image search for binding posts, I couldn't find anything like them and figured they were long out of production.
However when researching how long the knob I was using has been around, I found myself over on radioshackcalogs.com where they've digitized all the Radio Shack catalogs back to the very first one in 1939.
I found the knob, thought I'd continue browsing through the catalog. On the very next page, I saw the exact same binding posts that were used on the Western Electric amplifier. And unlike a lot of commodity parts in the catalog, they actually had a name attached to them. Eby.
So I thought with that information, I might be able to find some surplus place with a bunch of them that I could hoard.
But ultimately what I found was that not only was Eby still in business, but they still had the molds for those old binding posts which were patented back in 1925. I had to pay for them to do a full production run, bit by God I ended up with the exact binding posts that were on that Western Electric amp!
The brass plates are etched and enamel paint filled, and not just screen printed or anything like that.
In spite of the frustrations, it was a real labor of love.
Here's a better shot of those binding posts.
An externally hosted image should be here but it was not working when we last tested it.
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Are we to presume you've been inspired by fresh topological opportunities available when passage of dc in the coil is permitted ? Keen to explore what happens as magnetic operating point varies ?
Funny that, the binding posts are what first inspired my comment. Believe it or not Tuft's EE Dept back around 1990 threw all their old instruments into a dumpster. We filled our station wagon with as many as we could, maybe 100 or so. We sold duplicates but I still have a few, especially beautiful are the 1940's era power meters and electrostatic voltmeters. The jeweled movements and mechanical technology are amazing.
Thanks, Jan. It's a terrific effort on behalf of the guy behind the stop frame animation, and the depth of field in the sem is great. It's a great tease, because I'd just love to see real time play in high fps slow-mo with the resolution and depth of field SEM can bring.........it's impossible to do though, I think.
I predict that, in real time, the cantilever would be seen to flex during play, and any indentation of stylus into vinyl would be negligibly shallow. The effect on signal tracing distortion is very similar from flex and indentation, and they are hard to tell apart because of this. I would love to settle that by observation..........or otherwise.
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You are forcing a motor generator to produce more current. You can hear that, but there seems to be a point where it starts to happen as you increase the load. It behaves in predictable and familiar ways - and it sounds like damping and it's the only thing that can explain it.
Cheers, Joe
PS: The Jubilee went from producing 0.35mV to about 0.23mV. That's the penalty.
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Do you include custom cables that adapt the binding posts
to RCA jacks ?
It may be the only thing you can think of, but there may be other possibilities. You might try to do some experiments to confirm or refute your hypothesis.
I think you've hit the nail there. If Scott provided about 15 dB of gain before feeding his cart directly into the A-D, there would still be circa 25 dB OL margin at HF on a 5mV cart at 5cm/s. .
Very nice!
Great guess, looks like I wasted 12dB or so on my first shot, not a single pathological tick or pop.
Unfortunatley when you put physical numbers on this the arguments make no sense. A 100uV out at reference level MC with 6 Ohms coil resistance gives 16.7uA current (shorted) so by these arguments 16.7uA into the cartridge should defect the stylus as much as the reference level groove. Damping requires force, right?
Guess I'm on Joe's ignore list just as well.
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Get a motor to play with - turn the spindle and put a Volt meter on the terminals - you will see the meter moving. Use another motor to drive it and the voltage will be constant. Now short the terminals - the load will now be the internal DCR of the motor's coil - note now how much more force it takes to turn the spindle (you can even at this point calculate I as you can measure R and you know the value of the unloaded V). Similarly experiment with a driver/speaker - the force required to move the cone is higher with the terminals shorted as it now produces current into its own DCR. Same principle.
If you can think of any other experiment(s) to try to falsify 'hypothesis' - then let me know.
I have told hundreds of users about tweaking cartridge loads for over 30 years - interesting that you can hear easily when you over-damp a cartridge by using a too low R load. But this is good since we are now likely to find a sweet spot.
Also, whenever a sweet spot is heard, and it can be quite dramatic when you do, then it always seems to have an R that gets a lot closer to the DCR of the cartridge. The DCR is a good guide to the generator's impedance, especially with MCs. I also like MMs which have lower DCR and low inductance, as they seem to respond the best. A Grado Platinum is a case in point - 2K versus 47K? Something good is happening and it is consistent in results.
Cheers, Joe
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Are we to presume you've been inspired by fresh topological opportunities available when passage of dc in the coil is permitted ? Keen to explore what happens as magnetic operating point varies ?
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You got it put a current in the cartridge and watch the stylus move...not. Think about it, a motor and speaker require a substantial power conversion efficiency, a phono cartridge delivers a minuscule amount of power to the load compared to all the energy dissipated dragging it down the groove and waggling with the entire tonearm assembly. Basic conservation of energy.
Simple de-Q'ing electrically does not necessarily have anything to do with electo-mechanical damping.
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