Platter mat insanity


I was doing an idler upgrade to my 401 (more anon) and when finished used the Keystrobe disk to ensure speed. I use a 10" EP as a platter mat. I played a bunch of albums and it sounded fantastic. On the 6th side, I noticed I'd forgot to remove the 4" strobe disc. Duh. I took it off and figured VTA was responsible. So I lowered the arm to see if that made it sound so good. Nope. Put back on the 4" strobe disk and raised arm. The awesome sound returned. So air under the record removed haze, smearing, flattened soundstage and muddled bass; and made it so more musical. Comments... 
128x128noromance

Showing 5 responses by lewm

Sleepwalker, Please tell me how a platter mat can affect wow and flutter.  Maybe there would be an effect on measurable rumble, depending upon where and how you measure it, but I am straining to understand your comment on wow and flutter. 

Also, I have owned two SP10 Mk2s and now own an SP10 Mk3.  In all cases, I could not fall in love with the factory-supplied rubber mat(s), thick and heavy though they may be, once I compared them to other options. I am using a Boston Audio Mat2 on my Mk3; this is consonant with the belief that the mat should be acoustically "like" the vinyl LP.  I tried a BA Mat2 on my Victor TT101 and liked it but since then have come to like an SAEC SS300 metal mat, better.  (There's surprisingly very little difference, but I favor the SAEC for better transient response.) On my Kenwood L07D, I have absolutely fallen in love with a custom made copper "platter sheet" that replaces the OEM stainless steel platter sheet.  (Here is where EMI shielding may well play a pivotal role.) These experiences have caused me to throw out the rule book when it comes to mats, except I always have found any sort of rubber mat to be inferior to the other approaches.  That's just me and my experience in my systems.
These last few posts sort of illustrate the "dilemma", if this issue could take on the dimensions of a real dilemma.  I cannot disagree in the slightest with what Tom Mackris wrote.  It makes perfect sense.  But then we have to take into account the actual experiences of the rest of us.  Mats with an acoustical impedance close to that of vinyl are preferred by many but not all.  And why do metal mats occasionally sound really good?  Many of us pay many hundreds of dollars for copper mats, because we think they sound great and that copper sounds better than other metals, for example. (In this case, I think part of the mechanism has to do with the copper mat acting as an EMI shield, and maybe copper, being softer than many metals, is closer in its acoustic impedance to vinyl than other metals.) Likewise, I am not going to tell a person who loves the ringmat or the resomat that they are "wrong".  I would agree that some of these choices are preferred because they may generate a kind of euphonic distortion, but that's OK.  Platter mats are like seasoning on food; a small detail that makes a big difference.  Anyway, for noromance, I am convinced that he is liking the undamped sound that arises from raising the LP off the platter.  I think he proved that to himself with his experiments.

Can't agree that any of this pertains to the thick rubber mats that were typically supplied with even the best Japanese turntables of the 70s and 80s.  Almost any alternative will sound better, IMO.
noromance, The intent of my post was not to suggest that you purchase a Resomat.  I was merely trying to point out that possibly the inadvertant effect of leaving the strobe disc on your platter, thereby raising the LP off the surface of the mat, was analogous to the effect deliberately achieved by using the Resomat.  You may be liking that effect of letting the LP resonate freely in air, essentially. 

By the way, the Resomat was not by any means the first and only implementation of the idea.  Decades ago, the Transcriptors platter did the same thing; the LP sat on felt dots mounted on a set of regularly arranged pucks fixed to the surface of the platter.  It was not even possible to use a conventional mat with the Transcriptors.  I am guessing that the Transcriptors idea must have influenced Vic of Trans-fi, in his design of the Resomat.  Vic is English.  Transcriptors was a British product.
Have you ever heard of the "Resomat", made by Trans-fi in England?  Contrary to most dogma, it raises the LP above the platter on a bunch of rubber tips. This permits the LP to resonate freely.  That mat has a loyal following.  So, maybe you are in a way correct about why the strobe disc effects an improvement in SQ, according to your ears.  Of course, be aware that VTA may play a role, in fact.