sasaki@harvard.ARPA (Marty Sasaki) (07/25/85)
Just a few questions...
o What is a "reflex" record clamp?
o Does anyone have any information about Merrill's clamp? The ad's
claim that the clamp clamps the edge of the record. How does this
work?
o Does anyone have any experience with the solid mats? By solid, I
mean out of stiff material (like acrylic). The Goldmund and the
new SOTA mat are two examples of this.
o Someone made a funny mat/clamp that was a vacuum clamp. The funny
thing is that you used a pump to produce the vacuum, then you
disconnected the pump to play your record. Was this any good?
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Marty Sasaki net: sasaki@harvard.{arpa,uucp}
Havard University Science Center phone: 617-495-1270
One Oxford Street
Cambridge, MA 02138herbie@watdcsu.UUCP (Herb Chong [DCS]) (07/28/85)
In article <275@harvard.ARPA> sasaki@harvard.ARPA (Marty Sasaki) writes: > o Does anyone have any experience with the solid mats? By solid, I > mean out of stiff material (like acrylic). The Goldmund and the > new SOTA mat are two examples of this. i may be biased, but i've said this before, i can't find a physical justification to use an acrylic mat unless it can be shown to have exceptionally high internal losses to damp out any record resonances that may be transmitted to it. the name of the game in turntable platter mat is to kill resonances. even the best acrylics don't do as good a job as a rubber mat. if the acrylic mat is extremely hard to transmit vibrations to, then all the sonic energy in a record just reflects around until it finally loses energy through the damping of the record vinyl itself. the Rega's have this problem with their glass platters. the thing rings in the upper midrange and the felt mat doesn't kill the vibrations. a good rubber mat like the mission or platter matter cleans up the midrange provided that a clamp is used as well. > o Someone made a funny mat/clamp that was a vacuum clamp. The funny > thing is that you used a pump to produce the vacuum, then you > disconnected the pump to play your record. Was this any good? the mat you are refering to is made by audio technica. i haven't used it, but i have used Luxman vacuum platter turntables. they work exceptionally well. no warp flutter no matter how warped the record itself is, and very good damping because the underside of the platter is where all the damping material is. it is not as good as it could have been because the platter itself is hollow and it is possible to get the platter to resonate from what's being played. there was a motor driven vacuum model and a hand lever model. no need to use a clamp with these. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu