david ellwood
Kirabosi Kognoscente
I think the Captain is either pretending to be stupid, or he is stupid.
A new belt for the Linn LP12
- Thread starter Mike P
- Start date
Tony L
Administrator
In fairness belts are far more complex than one initially thinks, especially in a turntable such as a Linn where it also impacts the suspension. Belt thickness also impacts the speed as the arc over a curved surface such as a pulley is the mid-point of the belt thickness. The thicker the belt the wider the arc. On a very fast-running drive system such as a TD-124 this can become significant and you’ll find different belts need differing amounts of fine-speed adjust.
PS I actually figured this out when getting grilles made for my JR149s: to know the length you need you have to measure half the grille thickness wider than the circumference as when you bend a material it will usually compress and stretch around its mid-point, i.e. the outside gets bigger, the inside smaller. The problem is different materials behave in slightly different ways here so it gets complicated real fast!
PS I actually figured this out when getting grilles made for my JR149s: to know the length you need you have to measure half the grille thickness wider than the circumference as when you bend a material it will usually compress and stretch around its mid-point, i.e. the outside gets bigger, the inside smaller. The problem is different materials behave in slightly different ways here so it gets complicated real fast!
The Captain
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Hi Mike, what is this difference in material? Both are rubber, no? The mechanical characteristics are surely for it to just spin the platter at 33rpm- as I assume the blue one will, I mean surely this is page 1 stuff for any belt's role.
The Captain
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What a charming post. Most kind you are david.
The Captain
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Hi Tony, but surely the aim of any new belt is simply to be of the correct thickness to spin it at 33rpm like the Linn one does. Ok if it's too thick, then it'll either be slightly slow or fast. So the new one needs to be made so it's not either, but bang on 33rpm. That's page 1 design principle; if I need a new belt, this is something I expect.
Furthermore if you do find a new belt -fractionally- off.. 1/8th turn of the motor screw, & that's sorted.
If on the rare time you do find it's more than a fraction, it's faulty, so you send it back for a replacement.
Tony L
Administrator
Yes, that is all perfectly fair, and I have no opinion on Mike’s belt as an LP12 replacement. I’d expect it to be different though as it is a very different material, far more compliant. I can’t remember what it is, but it isn’t normal rubber. My comments are entirely based on experience from the TD-124 where the correct size (most if not all 124 belts are far too tight on the 50Hz pulley), lower tension, and lack of shedding is a total game-changer IME. I’ll leave assessing LP12 performance to others, I can’t predict if I’d like it or not in that context. I only ever used Linn belts way back when I owned one. Never experimented with any third-party alternatives.
flatpopely
Prog Rock/Moderator
When I swapped the Linn belt for the blue one I did notice a drop in overall 'noise' when playing vinyl. This allowed more micro details to come through and make the music more enjoyable.
sq225917
Bit of this, bit of that
It's measurably different to a qlinn belt in terms of speed stability. I'm not sure if the image links are still live where I measured it back to back vs a linn belt. I did a spectral power analysis of multiple test runs and the blue belt was always cleaner, ie closer to the test record recoded pitch.
The Captain
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But measuring something in terms of microscopic tiny differences is surely one thing, & sitting with ears & actually being able to detect these micro differences is a very different matter. Surely. Unless.. you've been genetically cross bred with an owl, or maybe you sit with one of those dog shame collars on & lie flat twds the Lp12 to detect things.
The Captain
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HiFlatP,
I'm just trying to ascertain how this is at all physically possible really, one rubber belt to another. I am very sceptical: I've read some people actually saying they can hear a difference one side of the felt mat.. to the other! Now that.. is preposterous nonsense, them just hearing what they want to believe. Isn't this in a similar vein-? A rhetorical Q of course.
Tony L
Administrator
Surely you could make exactly the same argument about every one of the hundreds of changes that have been made to the LP12 since 1972? Power supplies, corner braces, glued vs. welded subchassis, armboard marterial, different springs, motor bearing cup, grommets, multiple main bearings, baseboards etc etc etc. Nothing on the LP12 stays the same!
The Captain
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Well yes I agree: tiny things like replacing grommets, turning the mat over, or even taking the lid off & saying they can hear a difference, instead of just wishfully thinking they can, is all preposterous nonsense.
flatpopely
Prog Rock/Moderator
I and YNWAN once believed the orientation of the mat could not make a difference, then we heard it.
flatpopely
Prog Rock/Moderator
No it’s not.
The Captain
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Yes it is.
I've tried each of these 3 things FlatP, a good few times over the 20 years+ I've had my Lp12.. & then trying my damndest to hear one iota of difference afterwards; if I cannot then I can say with certainty, it is utter nonsense.
The Captain
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I'm just trying to understand how anyone could argue that a different rubber belt can possibly make any sonic difference. Just saying 'it does' isn't especially useful.
How can one argue in terms of function, that another rubber belt can somehow (it seems magically unless I'm told how) make the motor quieter- I mean just typing that seems absurd. I'm trying to understand the thinking, that's all.
How can one argue in terms of function, that another rubber belt can somehow (it seems magically unless I'm told how) make the motor quieter- I mean just typing that seems absurd. I'm trying to understand the thinking, that's all.
The Captain
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Haha! That is so utterly ridiculous. I never thought anyone would actually admit to this magic act.
How do you suppose it does this then?? This'll be amusing to read, but I don't suppose an answer will be forthcoming.
flatpopely
Prog Rock/Moderator
Are you calling me a liar?
The Captain
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Not neccessarily; I am calling you a fantasist FlatP.
flatpopely
Prog Rock/Moderator
The same fantasist who once correctly named the mains cable being used (out of 2) 6 times.
Honestly just buy a blue belt for £25 and hear for yourself rather than projecting your disbelief on those who have one. Otherwise you're just trolling, check the AUP.
Honestly just buy a blue belt for £25 and hear for yourself rather than projecting your disbelief on those who have one. Otherwise you're just trolling, check the AUP.