Just a couple of thoughts since I'm here. Clearly folks will tinker with Techies and find what they find. But in the context of your new discoveries (and harking back to an earlier thread on clamps) a clamp or weight does potentially 3 thingsQuote:
Originally Posted by Marco
1) - intended - causes a better coupling of the vinyl to the support, which if we believe the impedance match energy management idea causes a better result
2) - for weights, adds strain on the bearing, and buggers the suspension on suspendeds
3) - it acts as an upside down platter in the context of ringing, energy transfer and loss etc
All of these will impact on the final sound. Whether they "improve" it is in the ears of the beholder. Sounds may be preferred, but will not necessarily by "neutral". I suspect what is finally liked by any individual depends partly on their preferences, and partly on their other equipment and how it balances with it. Martin, who has written most recently on this Techie platter changing, and the ETP, has a distinctive and unusual tonearm, which however lovely he may find the sound, at least mechanically has some distinctive features which are unlikely to make it "neutral". So his choices will be relevant to how his record player, including the arm, sound. Almost certainly that won't be the same for everyone. I remain slightly bemused, given its outstanding reception elsewhere, that I appear to be the only person on the forum to have heard an FXR on a Techie. That clearly affects how I interpret what I have heard regarding platters. (It also reflects my tastes and my "take" on "neutral". If I had to sum up the FXR sound it is "Pink Triangle". They are made for each other.)
Back to clamps/weights. Assuming a closer contact between record and support is desired, it may not be achieved by weights and clamps. Oracle had this right, by having a soft mat into which the record could be squished, and a platter which was not flat, and a clamp washer, so that the clamp "bends" the record and the force applied to the centre is spread to the edges of the record. A straight weight presses down on the middle of the record, which is likely to lift the edge of the record up a tiny bit. Either way - unless you have a soft compound mat, pressing the vinyl harder against the mat shouldn't make a difference to the contact. A soft mat will squish into the grooves and therefore have a larger overall surface area in contact
Forget 2 - it just saves me the bother of titting about with weights on the PT, and means its probably a good idea to have an upgraded bearing on the Techie
3 - the upside down platter. If we are bothered by the impedance match / energy transfer idea (and not all of my chums are) then it is going to apply to an object on the other side of the record. However, a weight is mechanically coupled to the vinyl, via a paper label and so will be a very damped impedance match. It will however receive energy and do something with it. It will also contribute its resonances. If you pick your weight up you may think it fairly "dead", but hook a wire round it and hang it by the wire and tap it with a nail and it will ring. The energy from the stylus will travel through the vinyl as previously discussed. It travels horizontally as well as vertically. The record which is thin vertically is "a very thick record" horizontally, and so, there will be energy efficiently travelled to the label area to interface with the weight. So if you worry about your platter material, you also need to worry about your weight material. And unlike the platter, the weight is not coupled to a bearing to other parts (like a sub-chassis on a PT)
As an aside - this emphasises the "rigidity" thing. The "upside down platter" of the weight has a resonance/ energy coupling relationship with the record - but no support function. If the platter were the same dimensions, only covering the label area, with the rest of the surface unsupported - well, you get my drift. This is where I struggle a bit (along with relativity, event horizons in black holes, and the big bang). A Pink Triangle acrylic platter is completely rigid in my dimensions, as is a rega RB300 arm tube. The diagrams on funks web site showing the bending on the arm, are clearly not to scale. The problem is that the stylus movements needed for low level high frequency notes are tiny in a measure I can't get my head round. And, allegedly, at this level, things bend. The easiest way I can get my head round it is to enlarge everything. Make the platter 1 mile across, and I can see how it can move a bit at the edges. If the platter moves, or the arm bends, that creates a signal in the cartridge generator by moving the generator relative to the stylus tip.
Of course all that drivel was in terms I relate to , not proper engineering or even heaven-forbid relevant scale. So keep watching out for the cats. Or just listen and go with what sounds good :)
