Hi Mike,
On your instructions you refer to an arrow marked top. My base plate has no markings or arrow on it whatsoever - Is this ok ?
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Hi Mike,
On your instructions you refer to an arrow marked top. My base plate has no markings or arrow on it whatsoever - Is this ok ?
Hi Robbie,
Did you get your Base Plate from Dave??
In the earlier version of the Base Plate when it was attached to the chassis with bolts, an arrow indicating "UP" was placed on the Base Plate, as the bolts holes were not symetrical about the centre.
In the newer version which is attached to the chassis with epoxy resin there are only the three Bearing bolt holes to worry about,
However it was sugested that one of the three possible positions be marked "UP" so as not to cause any confusion, "to wit".
I have had my MN bearing a goodly while and am more than happy with how much it has improved the SQ over the stock and Vantage bearing. I have angsted over the base plate as I can totally see how it would improve SQ still further but I just don't want the platter lifted higher (Funk and bonded achromat) and if I'm honest didn't want to shell out any more dollar. So, after much thought and trepidation I decided I would permanently bond the bearing to the chassis thereby realizing the sonic benefits of improved structural rigidity. This is not for the timid as it is irreversible but having done it I can report definite improvement in low level detail (especially instruments "well back in the mix") and tighter, deeper bass - plucked double bass in particular.
I wanted to take the deck down to remove the pitch control as I've just bought a new top plate with no cut outs for the pitch control or 45rpm adapter so this was the ideal opportunity to "do the bearing"
Having totally dismantled the deck and removed the bearing I thoroughly cleaned the bearing case and the bearing well with acetone before pouring 25ml (20ml would be better I think) of mixed fibre glass resin into the bearing well. This has about 5 minutes of working time and sets in 20 minutes so you need to be nifty. Having partially filled the well I then gently placed the MN bearing into the resin and secured as usual with the 3 motor bolts and PCB screws - you need to fit the PCB because there is a deal of play in the bearing with just the 3 bolts. The bearing will displace some resin out of the well which will fill the void between the undersurface of the bearing and the chassis which results from the 3 proud mounting lugs. All the bolts and PCB screws were fully tightened and the assembly left for 60 minutes for the resin to fully harden.
There is no going back after this! If you FUBAR the deck is scrap!! There is no way to remove the bearing. Like as not you will also find that the 3 bolts will be fixed solid as a bit if resin will find its way into the threads even if like me you remove, clean and reinsert them. However, this is not FUBAR because if you do need to remove the PCB in future you can drill out the bolt heads and slip the PCB off and then (probably) remove the bolts with a mole grip.
Having reassembled the motor fired up no problem ( phew) and the improvement in timing and detail and bass was instantly obvious. So this "tweak" worked out very well but as I say does have the potential to seriously spoil your day if you get it wrong.
As a bonus having removed the pitch control I connected the earth wire that was previously attached to it and the arm board so that the arm board was earthed direct to the PCB earth screw instead - this totally removed the little bit of hum I was getting previously since installing the Croft MC headamp. previously with no music playing there would be audible hum with the volume pots above about 5, now I can wind them right up with no hum at all!
So all in all a very worthwhile few hours
Not attached and piccies as there really isn't anything to show
Go on, show us your new top plate and I'll give you a wine gum.
Very innovative idea Stephen. It should not have been too scary for you though. If you pull peoples faces apart for a living ... somewhat more 'mission critical'?
You have got me thinking though! The idea would not work for the standard bearing as that should have the option of removing it every now and then for a service. There may be other things that could be plugged into the bearing well that would increase rigidity. hmmmmm
Too kind!
Definitely wouldn't work with the standard bearing or any variant with an "open thrust plate" design as the resin would foul the bushings - only an option with a fully enclosed design like the MN
I'll get some piccies together shortly
I honestly do not like the idea of permanently bonding my Bearing into the chassis, as you say Stephen it is rather radical, whether you use epoxy resin or fibre glass resin. There are many reasons why you just might want to remove the bearing or disassemble the whole unit.
My Bearing Base Plate is not expensive and although permanent when installed, is does allow the removal of the Bearing and PCB with ease. It also permits the use of the special steel bolts which allow for much heavier clamping force onto the Base Plate. You must understand that these bolts not only hold the Bearing down, they also serve to clamp the stator assembly of the actual motor to the Base Plate. (or the chassis in the OEM state)
Secondly the BBP covers a very large central area of the chassis which is the weakest area and so it offers greater rigidity as a mechanical structure.
Hi Mike.
Wouldn't disagree with any of that. My "tweak" comes with a health warning but definitely works in terms of improved low level detail retrieval and bass extension and control which I understand is what the base plate offers,
This is clearly an "off licence" solution and I can totally understand why you would not support it. However, I'm a Black Country man living in Yorkshire so have short arms and deep pockets :wink:
Indeed, Mike - and quite simply, it allows the bearing itself to perform to its full sonic potential. I was shocked and stunned at just how much more ‘grown up’, weighty and purposeful sounding my SL-1210 was after fitting the BBP, having up until then used one of your bearings (and loved it), but not realising *just* how good things could get!! :)
Marco.
How can I argue with a man from Yorkshire especially one with short arms.