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I may be out of touch...saw this on Instagram. Does anyone recognize this or know what mod of LP12 this is...
Follow Ups:
Here's some more specific info on that stripped down LP12.
Nt
I sent the person a message on Instagram, and the brief reply was that the modification was popular in Japan. Seems extreme...I would have thought an outboard DC motor or new arm would have been more effective. But these mods are free. The person also made some interesting speakers.
a wierdness of Japanese.
..
Nt
Nt
That Lp12 has been disassembled from its wood surround (plinth). Nothing needs be mutilated. It stands upon the three suspension studs tied to the motor plate. So the studs and motor plate provide footing while also holding the motor into position.The springs, concentric about each stud, support the subchassis with arm, as before.
It's somewhat compromised in build due to being so thin and light. It's a hack. It works, perhaps pretty good.
-Steve
Edits: 08/10/17 08/11/17
In the link posted by kuma you see exactly what is going on and the player is resting on the bottom of the suspension springs. But, the sub-chassis is still floating as the springs sit in compression with a fixed end at the bottom of the bolt just as they are when a plinth is used. The difference in this case is that external vibration enters the system from the bottom of the suspension bolts and is then filtered by the suspension before entering the floating mass. With a plinth, external vibration enters the plinth then goes to the top plate and from there into the top of the suspension bolts where it is filtered before entering the floating mass.
To a first order, the isolation should be the same but the LP12 design is notorious/famous for being sensitive to its support so this mod will likely make a difference somehow. As official Linn updates are excruciatingly expensive this one is free, as noted by MaxwelIP.
I have toyed with the idea of re-finishing the plinth of my LP12 (way down the list of my audio priorities) so maybe I'll try this one day.
Regards
13DoW
re: does this design isolate from the supporting structure or does it not?
In the top photo we can see that the three spring studs are located on 3 footers which, in turn are situated above 3 rectangular blocks of some unknown material.
As I view the photo I notice that it is the adjuster nut, located at the bottom of each spring, that makes physical contact with the footer. --(the nuts are locked into position by means of the screw threads they fit onto)-- I suppose that the three foot pads offer some sort of isolating quality. However the contact between adjuster nut and footer is a solid mechanical contact. In this configuration the only thing the springs support is the motor plate and everything attached to it. I presume this to be a lighter load than it would be if the springs were supporting the subchassis, platter & bearing and tonearm/armboard.
The only thing the springs isolate from is the motor plate with motor.
-Steve
Edits: 08/11/17 08/11/17
The springs hold up the sub-chassis from the bottom of the bolts (springs in compression). The platter and arm board attach to the sub-chassis so they are isolated from the bolts. To a first order, whether the bolts are held from the top (with top-plate attached to a plinth) or whether the bolts are supported from the bottom (as in this case) is the same for the floating stuff. If you push the center pin the platter will still bounce up and down in typical LP12 fashion. The motor is still attached to the top-plate so is 'grounded' through the suspension bolts rather than from top-plate through the plinth. The motor is isolated from the platter, as always, by the belt compliance.
13DoW
Right. Now I see it as:
The studs are rigidly tied to the motor plate. So the motor plate becomes part of the footer assembly. It also holds the motor.
The springs support the floating subchassis as before. But now the force of the stand flows up through the center of the springs within the studs.
More direct. If you put some thought into footer and support shelf isolation, it becomes quite good, perhaps.
-Steve
If it had been a very old LP12, you could have said it was available in chassis form, which it was as an option back in the 70's.
Regards,
Mike.
I am guessing that the top cover is being supported from underneath in some fashion with the sub-chassis hanging from it in normal fashion. That may be what the black block is doing. And it looks like the metal cross brace that holds the motor board is also hung from the top plate.
Or, could that black block be supporting the bottom of a suspension bolt so that rather than everything hanging from the top plate, everything is being held up by the suspension bolts with a three point contact to the support shelf? The sub-chassis would still be floating from the top-plate that itself is held up by the suspension bolts.
I think the LP12 plinth is nice to look at, especially the custom one linked.
Regards
13DoW
I must say I am more impressed with his culinary adventures than mutilating a Sondek.
Me too.
What the guy doing the plinthless mod doesn't appear to understand is the the LP 12 plinth is not just a box to hide the internal mechanics from sight. It has a function which is to act as a sink for the excess mechanical energy ( excess = that not converted into electricity by the cartridge motor) that is generated during playing a record.
In fact the material that the plinth is made from affects its ability in this area and those Linnies that have compared 'tables with different plinth materials will have found that they sound different to one another. Unfortunately some of the best looking woods make a less good sounding turntable.
" It has a function which is to act as a sink for the excess mechanical energy ( excess = that not converted into electricity by the cartridge motor) that is generated during playing a record."
Through the springs?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Good point.I'll concede on that :-)
I have always thought of a hollow TT base as being a big echo chamber for motor noise and outside vibration sources, causing problems rather than solving them.
That's just how my mind works. I could be wrong.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Yes, I have sympathy for that view. Take a matchbox, empty out the matches, place the box against your ear and lighly brush it with your finger. What a lot of noise that causes. Perhaps it serves as a simile for what goes on in a box type plinth.
draining mechanical vibrations out of the turntable? This is why footer and the support also matters equally. And extreme attention is paid to the top plate fit to the plinth. Very difficult or almost impossible to eliminate vibrations but what they are doing is to create the path for it to pass it through quickly without storing it or moving back to the turntable.
Having to experiment with various plinths, I was rather surprised there is a drastic I mean a H-U-G-E difference amongst them. I think that it's counter to neutral crazy audiophiles, but some of them give a nice colours ( like classic Afromosia gives that distinctive Sondek flavours ).
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