@Richard.Dane could I request that this thread is re-opened and this post added to it please?
In doing some upgrades to an LP12 I’ve swapped plinths but didn’t go to the lengths of a total strip down to the bare top plate.
So perhaps unsurprisingly I’ve got slight gap at the motor corner which rattles a bit when you tap it in a small area.
It’s a non studded top plate in an 80s Greaves fluted plinth.
The motor is now a Radikal DC type so has the foam ring between the motor and top plate unlike the old motor it replaced which was metal on metal.
I’ve read Peter Swain’s post about top plates on the Cymbiosis website and it is also discussed in his excellent set-up guide, which contains this warning:
It’s of critical importance that the top plate in the motor corner does not rattle against the plinth as this has dire consequences for the sound quality.
I will do a full strip down if and when I have the time and might even treat it to a trip out to Cymbiosis for a rebuild. I’m not confident I could bend the plate correctly so option 2 is most likely.
However it sounds pretty good to me, definitely the order of improvement I was expecting over a Lingo 2 and AC motor, so I’m wondering what I might be missing out on, if anything?
Has anyone any experience or opinion on the effect of a rattly top plate (especially with a Radikal motor?)
I still have my top plate from 1987.
About ten years ago I was very fortunate to make Peters acquaintance and on his first visit to our home set about some wrestling with the top plate on the living room floor.
Needless to say his intervention has delighted on many visits since.
Hi
Once you have a very competent fettler that knows how to do the top plate then the choice of motor with regards to rattle shouldn’t really matter.
But needless to say the Radikal is a very significant contribution to uber LP12 performance fettler permitting.
Bearing then Power supply motor combinations being the most important components.
It’s got a Karousel and Kore so is mechanically of modern spec except for the top plate and plinth (and an old Ekos).
Where I was aiming the question is whether the issue is made less critical with the DC motor, foam interface, tachometer feedback loop etc
Also, I’m interested to know any perfomance aspects where the rattling is known to cause problems - top end presence perhaps?
I really can’t fault the bass depth, punch and timing.
Hi
Bear in mind that there are two versions of Radikal other than standard and Klimax there is a first version and a Radikal 2
The latest one has a far better motor mounting arrangement and motor size to eliminate a variable problem sometimes occurring with the early one.
Yep, it’s the Radikal/2 with the brass bushings in the motor housing.
So you can nip 'em up nice and tight
And it’s an old Trampolin so there’s no fouling of motor and foot either.
Years ago a Linn dealer showed me how to correctly form the top plate bend over the knee (which is obviously comically pi** poor in terms of getting repeatable accuracy) and yet MUST result in zero rattle at both motor and switch corners before proceeding any further. According to him it’s THE minimum requirement to getting full performance from any Sondek.
This is one of those that to me just makes the LP12 sound “off” but it’s hard to pinpoint exactly why. The tonality will still be similar, but it just won’t be as engaging. If you’ve heard it how it’s supposed to sound, it is obvious, but if you haven’t it will still be a “competent” TT, so I don’t think you’d know it.
That’s the response I expected
The seeds were sown as soon as I noticed the rattle.
So now I find myself trying to pick out what might be wrong and not appreciating what is right.
Acoustic perception is mostly psychology after all.
Which is why we all love/hate this hobby isn’t it?!
To be honest, the only thing you’re really looking for is that it’s rattle-free all over. For someone experienced they will get it rattle-free every time and fairly quickly, so sounds like pretty repeatable accuracy to me. That said, it’s not that easy to build that familiarity.
Having heard the other two “big” alternatives to the original (Khan and Karmen), I still don’t think anyone’s managed to improve on the sound of it, even if they may be easier to put together.
