PS: There are two new models available:
i-qual IQ1300A
There is also another solution available ... Yukimu cvs-1
Both are about 900 - 1000euros as new now. Not cheap at all. Based on that, I got mine very cheaply.
I've seen that IQ1300a indeed on the WWW.
That yukimu is new to me.
€1000 is exactly 20 times as much as I paid for my AT666 (and the materials for the diy pump were maybe €30 or so)
Regarding vacuum pumping while the platter is spinning: We go to great lenghts to make a turntable vibration free and to have a bearing run as smoothly as possible.
If the vacuum system is run through a bearing, first of all the chances of leaks increase, as 2 airtight rotating seals are necessairy, so the old Micro seiki's and luxmans have more chance on that (and that Yukimo too).
2nd: starting and stopping suction gives a pressure wave (especially if it goes through that hose), so that is a big risk in inducing yet more vibrations into the turntable.
Also to create suction without pressurepulses (from a pump), it requires 1 or 2 vacuum tanks, so it quickly becomes cumbersome and expensive. Ideally you want a system with a proportional valve that is very controllable if no vibrations should reach the platter.
Also, a vacuum pump makes noise. Who wants to listen to that while the music plays? Maybe install it in the next room and run the hose over a distance....
If the vacuum can be hold longer than 1 side play takes, I don't really see the point.
There's not that much vacuum needed, the goal is to flatten the record so there is no warp.
Mine also holds vacuum easily longer than 30min. But that might depend on how warped and how many warps the record has. I have no real experience with that.
I also don't use it that much, I have 2 turntables that can fit the AT666 (that have enough VTA adjustment room and not subchassis)
Another issue might be, that if your platter isn't 100% straigth, you can get a little wobble between the vacuum platter and the normal platter.
Of course this shouldn't happen with a quality turntable, but a lot of turntable we play around with are 40+ years old, and a lot can happen in that time. Bent/warped platters happen.
A 0,2mm warp in a platter might not be that noticeable when there's a 4mm rubber mat on it and then a record that,s probably not that consistent in thickness, but if 2 metal plates rest on top of eachother and there's a 0,2mm gap on 1 side, you notice straight away a wobble when pressing from 1 side to the other and you hear that metal tick.
I have such a platter on a ps-x75 biotracer. I don't know if it's a factory defect (quality control issue) or that something happend to it, but I have 2 ps-x75's (one is a parts machine) and one platter is dead straight and one is slightly warped. That platter is odd anyways, its a concave platter (probably also to put a little strain on the edge of the record, also to reduce very small warps), and it's cast. I haven't really looked if the at666 rests on the cast (and unmachined) inner part or on the machined outer part.
But these little niggles can also happen. Not that good if you invest in a €1000 IQ1300a and have to return it (or find a better turntable)
Short answers:
* Nope, I have no record press (yes, I have seen photos of that (or how Luxmans versions of the same looked like). I just have pump and the mat. Is that really necessary? Perhaps one could be done by yourself (DIY)?
I guess whether or not it's useful depends on how warped your record is.
Without the press, there is no suction/vacuum if there is a warp large enough to give a gap at the seals; you have to press the outer edges of the record to close that gap.
I don't have that many warped records (actually only one that I know of...), and I manage to create suction with that record pretty easily, but I have to press with my finger on a few spots on the edges to create the vacuum.
You can see that in the video below (and the record with my largest warp can also be seen). At some point the seals grab and vacuum is pulled.
(in the description of the video a summary on how I build the pump and what materials I used can be found)
But with extreme and multiple warps, I can imagine that press to be really handy. Then again, if you're finished with it, where do you put the thing....(dismantle it again?)
And if you're a bit clumsy...what is the chance you accidentally hit the arm with it when taking it off or putting it on...
That press can be seen in the picture below.
shouldn't be very diffucult to make if you need it (it basically holds the edge of the record down all around so the seals can do its thing).
The design is not that sophisticated; a press that you can fold out real easy would be so much better (like folding out a smalll tripod, or fold the legs out in a rotating way)
?
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