To Clamp or Not to...

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  • 10-15-2009, 07:53 AM
    poppachubby
    To Clamp or Not to...
    Good Day AR party people. I will try and simplify this as best I can. There are 2 hifi shops in my city. They both sell top shelf products, particularily when it comes to vinyl.

    Shop number 1 pushes clamps in general. They have several varieties for sale. They are also the local Pro-Ject dealer and push Pro-Ject clamps and upgrades. Clearly, they are for the science of clamping.

    Shop number 2 has a no clamp policy. They sell none and advise against them. Let me add that these guys sell Linn products and are highly reputable. They feel that since the clamp attahces itself to the spindle, vibrations from the bearing will create sonic issues during playback.

    The problem I am having is this, I am in the middle of a "DIY" tweak for one of my tables. I am presently writing a CNC program to machine a piece of acrylic. I am going to use it like a mat with a clamp and see what the results are. I wasn't expecting to hear anything objectional about clamps.

    To me, the science of clamping makes perfect sense. Do you guys think I should worry about this? I am using a Technics SL Q2, not the greatest table in the world. They actually had said that the worse the table, the more likely the problem will occur.

    Hope to hear your input, Chubbs
  • 10-15-2009, 09:20 AM
    JohnMichael
    There are clamps, weights and weights that clamp, there are matless platters and matted platters. Some tables have heavy duty main bearings, others medium and some the shaft is the motor shaft.

    OH any way I do not use any clamps or weights. Of course I have a Rega and I am indoctrinated into the Rega way to play a record. Once my platter is spinning it does not stop until I am finished playing vinyl. So no chance to clamp since the platter never stops. I do use the Ringmat platter mat which I enjoy and it is far superior to the felt mat and probably most rubber mats.

    Not all bearings can handle the excess weight of a heavy clamp. I would be more careful with direct drive turntables. Also records can be weighted or clamped too much and the record can dish leaving the center lower than the edges. Turntables designed with a platter and clamp to compliment one another can be quite good.

    With your table I think you are on the right path to improve the mat and would be curious to read how the acrylic works for you. I am curious are you making the mat out of acrylic or a replacement platter. Again be concerned if there is an increase in weight if you go whole platter. Also as you may well know if the platter is too much thicker your vertical tracking angle will change and the difference in sound may have more to do with how the stylus rides the groove than an improvement in mats. Good luck and let us know what you decided.
  • 10-15-2009, 09:32 AM
    poppachubby
    Quote:

    Originally Posted by JohnMichael
    There are clamps, weights and weights that clamp, there are matless platters and matted platters. Some tables have heavy duty main bearings, others medium and some the shaft is the motor shaft.

    OH any way I do not use any clamps or weights. Of course I have a Rega and I am indoctrinated into the Rega way to play a record. Once my platter is spinning it does not stop until I am finished playing vinyl. So no chance to clamp since the platter never stops. I do use the Ringmat platter mat which I enjoy and it is far superior to the felt mat and probably most rubber mats.

    Not all bearings can handle the excess weight of a heavy clamp. I would be more careful with direct drive turntables. Also records can be weighted or clamped too much and the record can dish leaving the center lower than the edges. Turntables designed with a platter and clamp to compliment one another can be quite good.

    With your table I think you are on the right path to improve the mat and would be curious to read how the acrylic works for you. I am curious are you making the mat out of acrylic or a replacement platter. Again be concerned if there is an increase in weight if you go whole platter. Also as you may well know if the platter is too much thicker your vertical tracking angle will change and the difference in sound may have more to do with how the stylus rides the groove than an improvement in mats. Good luck and let us know what you decided.

    Great points John and thanks! To start, yes I have considered all of the fallout from my project. I am essentially making an acrylic mat which will sit on the platter of a direct drive table. My current mat is 5mm and this acrylic will be 10mm. I have tested this thickness and the VTA will be fine. If this works out as well as I am hoping, I may attempt an acrylic platter for a belt drive I have.

    I too have a ring mat and enjoy it. I'm not sure if I'll get everything out of the acrylic without the clamp. After seeing some higher end Pro-Ject tables at work, I think it's a great idea. We'll soon see...

    I was actually looking at a Rega specific clamp as they are designed to grab a small amount of spindle. My spindle just peeks out with this mat. I will be finishing the work on it hopefully tonight, I'll post some pics for sure.
  • 10-15-2009, 02:52 PM
    JohnMichael
    All this talk of clamps and platters I had to pull out the Funk Firm Achroplat platter. Since my system is more revealing with the Krell I thought I should give it a listen. Sounds good, better than I remember. Of course with the Achroplat on the table there is not much Rega left of my Rega.
  • 10-15-2009, 03:19 PM
    poppachubby
    Quote:

    Originally Posted by JohnMichael
    All this talk of clamps and platters I had to pull out the Funk Firm Achroplat platter. Since my system is more revealing with the Krell I thought I should give it a listen. Sounds good, better than I remember. Of course with the Achroplat on the table there is not much Rega left of my Rega.


    Never tried one but with a name like Funk Firm, how could it be bad? Great funkin name!

    I'm at work John and I've completed the "mat". It looks amazing, I'll take some pics when I get home, around 12/1. It's clear acrylic, however, I had to mill down one side to thin it out. The Gerber machine leaves a nice symettrical footprint of lines though. Not bad at all.

    The acrylic piece cost me 35 bucks and I have access to the CNC machine here. To pay for machining might be another 40 - 50 bucks. Not too sure. I may mill it down another 2 mm. It's presently 10mm thick and approx. 650g heavy. Chat soon...
  • 10-15-2009, 03:25 PM
    02audionoob
    What's the diameter of this work of art?
  • 10-15-2009, 04:35 PM
    poppachubby
    Quote:

    Originally Posted by 02audionoob
    What's the diameter of this work of art?


    292mm or for you Yankee Doodle, 11.5 inches, the exact diameter of the stock mat that came with the table.
  • 10-16-2009, 08:42 AM
    poppachubby
    Not too much response on this thread. I thought this topic would be of great interest for any anolog fans.

    So on that note, here now for it's first public display.....for the legion of awaiting fans (2 fans)....and for the audio world as a whole....

    .........The Acri-Mat!!!

    http://gallery.audioreview.com/uploa...3/DSC02482.JPG

    Not a bad name huh? LOL. I have some rough finishing to do on the edges and the spindle hole. I am now going into work to mill it down to 6mm thickness. Unfortunatly, this is a requirement to accomodate a clamp. It's still a nice, solid piece. I'll post some more photos once it's fully completed and ready for mass production in Japan, part of the deal I have with Sony.

    I also have some more thoughts to post regarding clamping and a few other, broader topics.
  • 10-16-2009, 10:17 AM
    poppachubby
    1 Attachment(s)
    Due to issues with the upload tool, I will post a couple pics, each in its own reply. I was quite proud of my tolerances on this cut, as you can see, it's balancing on end with no assistance.
  • 10-16-2009, 10:20 AM
    poppachubby
    1 Attachment(s)
    Oh ya....
  • 10-16-2009, 10:24 AM
    poppachubby
    1 Attachment(s)
    Well, that's it for now. You can see that the edges need finishing, which they'll get. Strictly aesthetics at this point.

    I will give some impressions once I've listened for a couple of days. What I really want to know though, is how it sounds with the clamp. For this we'll need to wait. Any ideas or suggestions are welcome...
  • 10-16-2009, 10:48 AM
    02audionoob
    Quote:

    Originally Posted by poppachubby

    .........The Acri-Mat!!!

    Not a bad name huh?

    What about Acrylimat? I've got dibs on that one.
  • 10-16-2009, 11:44 AM
    JohnMichael
    I could not tell from the picture but is there a dished out area for the record label. The label area can be a little thicker so the record will not rest flat on the platter if it does not have a recessed area for the label.
  • 10-16-2009, 01:20 PM
    poppachubby
    Quote:

    Originally Posted by JohnMichael
    The label area can be a little thicker so the record will not rest flat on the platter if it does not have a recessed area for the label.

    Sorry John, you'll have to explain that again. I think I'm understanding. The Acryli-Mat*TM noob Lic., is smooth across the entire surface. Are you suggesting a recessed or thickened diameter where the label sits?

    Not sure what thickened would accomplish...just explain your meaning again John, I didn't catch it fully. I can tell you at this point, I could recess the label area on the surface, but any thickening will mean reducing the overall thickness which I'm not willing to do.

    Perhaps the next one...I'm at work right now so I'll have to wait to divulge some chatter that's on my mind. I had a pretty mind blowing day. I went to store "2", from the OP of this thread. Spoke directly with the turntable expert, a Linn man. Incredible knowledge, not just of audio equipment but the concept of audio enjoyment as a whole. Somehow, we got totally off topic.

    I'm sure that quite a few guys on here are long past me. They know exactly what they want to hear coming out of their speakers. More importantly, they know which producers will provide the correct synergy to get it. In short, we spoke about this and a few other topics, stemming from the clamp issue.

    It was almost discouraging to realize that there's alot about myself that I am not sure about when it comes to audio enjoyment. I think the bottom line is simply this...

    LISTEN!!!

    I plan to do much more listening. You see guys on here, and all over with "upgrade plans". I personally have no plan. I wonder about the validity of such a plan anyhow. If you're not 100% certain of what you are trying to achieve sonically, no plan really matters. It's almost a certainty that you will achieve your plan and after some amount of time, be re-planning. I need to do much more listening to try and narrow down where it is I want to go in terms of gear.

    I think for now I'll enjoy what I have. Let the listening begin!!
  • 10-16-2009, 01:42 PM
    JohnMichael
    Look at your ttables original mat. Is there an indented space around the center? That is for the label area of the record. Most records are thicker at the outer edge and center label. That is why you made the mat smaller in diameter than the record. In order for the record to be supported by the mat you need a slight recess in your new mat the size of the record label. Again look at the original mat and I think you will see what I mean.
  • 10-16-2009, 02:36 PM
    02audionoob
    Here's a decent photo of an acrylic platter indented at the label area...

    http://farm3.static.flickr.com/2471/...99e5388519.jpg
  • 10-16-2009, 02:45 PM
    poppachubby
    Super, I can do that easy. I'll just use the rubber mats measurements. Thanks guys!
  • 10-26-2009, 04:46 PM
    jrhymeammo
    That's pretty cool, Chubby.

    How much does that platter weigh? Also, how does that affect your Vertical Tracking angle?

    JRA
  • 10-26-2009, 05:57 PM
    poppachubby
    Quote:

    Originally Posted by jrhymeammo
    That's pretty cool, Chubby.

    How much does that platter weigh? Also, how does that affect your Vertical Tracking angle?

    JRA

    The platter weighes approx. 375 grams and is now 5mm in thickness, same as the mat before it and does not affect the VTA. I am enjoying it quite alot and look forward to adding a clamp to the mix.
  • 10-31-2009, 01:55 PM
    hifitommy
    clamps not weights
    i have a nearly weightless clamp from france which i sometimes use bot mostly i use the sota relfex clamp. it takes a rubber washer under the record and presses the vinyl slightly down over it. i use this on my sota sapphire and alternate with an orsonic (small) clamp.

    i recommend the ttweights lightweight clamp and its price isnt prohibitive. ulstimately i want to get their periphery ring which holds down the outer edge fo the LP, great for some warps.

    i like your acrylic but wonder about how much spindle there is for the clamps to purchase onto. i might use some blu-tac or cheeep equivalent under the acrylic and on top of the aluminum (ooopsy, did i leave out an i for you canuks?).

    i once modified a rabco st4 tonearm for low mass by cutting the counterweight exactly in half (weighed in the lab at the hospital with a triple beam). i wont outline the entire mod here but suffice it to say i was able to reduce the required vtf on the XLM from 1.5gr to 1.0gr. modding can be fun if you stay within your capabilities.
  • 10-31-2009, 03:03 PM
    poppachubby
    Quote:

    Originally Posted by hifitommy
    i have a nearly weightless clamp from france which i sometimes use bot mostly i use the sota relfex clamp. it takes a rubber washer under the record and presses the vinyl slightly down over it. i use this on my sota sapphire and alternate with an orsonic (small) clamp.

    i recommend the ttweights lightweight clamp and its price isnt prohibitive. ulstimately i want to get their periphery ring which holds down the outer edge fo the LP, great for some warps.

    i like your acrylic but wonder about how much spindle there is for the clamps to purchase onto. i might use some blu-tac or cheeep equivalent under the acrylic and on top of the aluminum (ooopsy, did i leave out an i for you canuks?).

    i once modified a rabco st4 tonearm for low mass by cutting the counterweight exactly in half (weighed in the lab at the hospital with a triple beam). i wont outline the entire mod here but suffice it to say i was able to reduce the required vtf on the XLM from 1.5gr to 1.0gr. modding can be fun if you stay within your capabilities.

    Great advice Tommy, the spindle was a great concern and ultimately dictated alot of how the mat would turn out. The Clearaudio clamps are good for little spindle and of course clamps designed for Rega decks will grab almost nothing.
  • 11-01-2009, 10:02 AM
    JoeE SP9
    Quote:

    Originally Posted by hifitommy
    i have a nearly weightless clamp from france which i sometimes use bot mostly i use the sota relfex clamp. it takes a rubber washer under the record and presses the vinyl slightly down over it. i use this on my sota sapphire and alternate with an orsonic (small) clamp.

    i recommend the ttweights lightweight clamp and its price isnt prohibitive. ulstimately i want to get their periphery ring which holds down the outer edge fo the LP, great for some warps.

    i like your acrylic but wonder about how much spindle there is for the clamps to purchase onto. i might use some blu-tac or cheeep equivalent under the acrylic and on top of the aluminum (ooopsy, did i leave out an i for you canuks?).

    i once modified a rabco st4 tonearm for low mass by cutting the counterweight exactly in half (weighed in the lab at the hospital with a triple beam). i wont outline the entire mod here but suffice it to say i was able to reduce the required vtf on the XLM from 1.5gr to 1.0gr. modding can be fun if you stay within your capabilities.

    That lightweight clamp, could it be a Planax?
  • 11-01-2009, 11:05 AM
    hifitommy
    planax it IS
    i got it in a small group ofitems at a hifi store that took some stuff in trade. it requires some hand and finger strength to use it. for a while, my arthritis prevented me from its use. otherwise it does a GREAT job of immobilizing the disc on the platter.
  • 11-01-2009, 08:53 PM
    JoeE SP9
    I've had one since the early 80's. They are great for spring suspended TT's. No weight and pressure adjustable. I know you know this. This is for the benefit of others.
    I wonder why no one makes them anymore. Maybe I'll make (or have made) a couple and try to sell them.
  • 11-02-2009, 06:11 AM
    hifitommy
    its fremch
    and the design is quite different from others. i doubt that it is in production anymore.