Discussion in 'Turntables' started by 4-2-7, Mar 16, 2017.
For sure, What I think is going on is you and the pig got new clamps. Maybe there has been a spindle size change. Maybe the spindle they are adjusting them on as the templet is different then these two tables have.
I got a new Reflex clamp direct from SOTA last year (or early this year) and the collet in that one was so loose that the plastic screw fell out one day. I think the key is to keep it as loose as possible (to avoid excess wear on the cam/washer) while still getting a tight grip on the spindle and achieving downward force on the record. Definitely takes some trial and error to get it right - good news is that for a new clamp not needing the "full service" the collet screw is easily accessible through the spindle hole with a hex wrench.
As note, if a record is dished down in the center, you may still get good vacuum but the record center sits below the bottom of the clamp (the gap mentioned by LotusFool) - easily remedied by using the included washer to help push the record label up into the clamp.
My clamp is not new, at least the box it came in was from the Oakland period. However it does seem to have very little use, there are no indicators of it living a hard life.
I cannot slip a sheet under the edge of the clamp with it installed. When I power it up and apply vacuum and then shut it off, there are a couple of records I can get it to slip under a bit. Seems to be record dependent.
However if I have the table running and try to slip it under its easier to do so, as the movement of the felt pad on the bottom of the clamp seems to pull the paper in.
I have no issue with how the clamp works. I can hear the difference between a properly adjusted clamp and not, and that is the final arbiter for me. When you think of how the system works I don't think you can get a super tight seal once the vacuum is applied, because the record may or may not be true, the fabric pad and rubber lip is going to have a bit of compression to it, and the felt pad of the clamp is not going to be a hard rubber type of seal.
Actually as I think about it, I believe the purpose of the clamp is to pre position the record as flat as possible against the platter, and then when the vacuum system activates, the record is further coupled to the platter. If the distance between the record and the platter is too great, or there are too many voids, then the vacuum will not be as effective as it tries to couple the record to the platter. That is my intuition of how it should work.
I think once you experience the clamp working properly, but what you hear, that should be your final measurement that its working correctly. Not a piece of paper.
Would the reflex clamp still be beneficial for non vacuum sapphires?
I just tried two clamps a really old one I repaired and a nicer one. I have two tables with the glued on washer on the mat and one without. I even have another old clamp I could try but don't think I need to.
My findings using each clamp on each table, while running taking thin paper I could not get it to slip under the clamps rubber seal.
The bottom edge, you clamp seal is felt? I'v never seen that and maybe something someone other than the factory did. They are supposed to be a soft rubber. For one thing a clamp of some sorts should be used on a vacuum table to seal the spindle hole, felt would breath and suck air.
I dunno this does not feel like rubber. Maybe not a traditional felt but something fabric like.
That's right for the old ones,it's foam rubber.
My old one had a ring like that, the newer one has a ring made of a hard fiber material.
This is exactly what my new clamp looks like from the bottom. Once again last night, it did not stay in contact with the records surface once the vacuum came on. I know from trial and error that if I push down 20Lbs. it will stay in contact, but Donna has warned me not to push down that hard on the clamp as this will be very bad for the bearing. I'm only guessing that last night I was pushing down maybe 10 Lbs. Tonight I'll get the bathroom scale in front of the SOTA to measure, and try to adjust the clamp to work using only 10 Lbs.
Failing that, I will be returning this clamp and will be asking for recommendations for other clamps that will work for my SOTA
Now this is an interesting event to relate. I have one record that I enjoy listening, but the second side has a pop on it that lasts three revolutions and is quite loud. Every time i hear it I cringe, and tell myself I need another copy of this album. Well i put it on the Sota this morning and gave it a spin. I keep forgetting about this pop you see, and I did so this morning. When it hit I cringed, and I prepared myself for two more of them. The cartridge tracked right through the next two revolutions without an issue.
Why? I got no idea. Is it the coupling of the platter, clamp, and vacuum? Is it due to the SME V having better control on the cartridge? Take your pick, all I know is it did happen, and through multpiple playbacks of the song. I have found this table/arm/cartridge combo handles vinyl noise very well, but this was not expected at all. I nice surprise really.
Are you using the rubber washer under the records where the clamp is not maintaining contact with the label? Agree it should not take that much force to seat the clamp, a picture or two of your clamp and spindle might help us who want to help you.
[edit/add] I think I mentioned in your other posts in Dan's clamp thread, sometimes a record has a mild concave dish and the center gets more easily pulled down when the vacuum hits (but the dish is not bad enough to raise the record at the edges so you still get a good vacuum). I think this is what is happening to you, that is why I am asking if you are supporting the record center with the rubber washer that comes with the Reflex clamp. Try a few records with the washer in place under the record and see if this helps.
I contacted Larry (who built my TD 165 plinth) two weeks ago about a new cabinet and he indicated he is no longer doing this. If you contact him through AK it may be different though. Hope so, is work is great and he is a pleasure to work with!
Another one bites the dust. Thes folks are not getting any younger.
Oh yeah, I am using the supplied washer each and every time. It won't work at all without it. According to Donna and others, I shouldn't even need the extra washer because I just had a new lip and mat installed by SOTA ,and there is a permanent washer affixed to the mat. So I'm smelling a rat here. Using both washers this ought to work using 10 Lbs. I'll try to loosen the set screw some more tonight to see if that helps.
Now here is something I thought I noticed last night (but I may be wrong) I thought I could see in the platter's mat an "indentation" of the record's label. As if the vacuum was pulling the record so hard, it was leaving a mark?? I have measured the vacuum at the pump to be 7". But what it the vacuum is pulling on the record too much?? That would explain why the record is pulling down and way from the clamp. Just a thought...
Hmmm..I communicated with him yesterday. I think he’s just super busy and dealing with a backlog. Really nice guy.
Speaking of reflex clamps. Please educate me on this. Is it necessary to lock it in place on every record?
Oh, good to hear!
Ok, I believe me and the reflex clamp are good to go now. I got on my bathroom scale again so I can know how hard I am pushing the clamp down. I just did three trails on the same record and each time I pushed down 10 lbs, and each time the clamp stayed in contact with the records surface.
Last night's attempts were not measured, and I'll bet I only pushed down 7 lbs.
So I'm happy with my clamp and sota now.
It sounds simply fantastic and well worth all the effort and expense!
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