Sorry Stefanl, other than what I've written I can't say anymore, as I haven't had a noise problem to deal with. That said, looking at the logic of the Ladder of Importance - i.e. that the source is most important as losses here cannot be made up further up the chain (which is why it is turntable first, then tonearm, then cartridge) - the whole debate about DD, belt-drive and idler-wheel drive demonstrates that first and foremost within the turntable is the drive system. And behind the drive system is the motor (the various motor improvements and mods, DC vs AC and so on)! This is doubly true of the motors in idler wheel drives and DDs, as these are directly (DD) or near-directly (idler) coupled to the platter. So a lot of attention must be paid to, and in the case of both the Lencos and the Garrards, HAS been paid to, the superbulosity (TM ;-)) of the motors.
Given that the motors in these superb idlers are indeed themselves superb, I believe anyway that as little as possible must be done which might interfere with the drive system/motor. Also, to me, Dynamics are Sacred, which is one reason I always caution against overdamping. And the further I go the more I am against any type of damping, period. The problem with damping materials (Sorbothane, Dynamat, sand, lead) is that they do not differentiate between noise and music, thus, when damping noise and vibration, they also damp dynamics and detail (though a balance can be struck in which enough noise is suppressed to allow detail to emerge more clearly). I no longer use Dynamat or any other noise reduction, other than the plinth itself, which is "hard" and yet soft enough to absorb noise (especially with Direct Coupling) and not reflect it as stone would (aaahh the humble simplicity of good'ol wood), and glass epoxy, which controls vibration by stiffening the top-plate and is a form of CLD in its own right to cancel out noise (but does not damp in the classical sense like Dynamat, Sorbothane, sand or lead). Now, Direct Coupling is difficult to achieve without damaging the signal/music, but if done correctly, it is all positives (great reduction of noise drained into the plinth, even inaudible noise, meaning the noise floor drops precipitously) and no negatives (no loss of PRaT, bass or other sonic information). With the reduction of noise comes much greater focus, separation of instruments, transparency, speed, transients, bass detail, midrange, imaging, etc.....effectively a BIG step up the ladder.
Similarly dynamics. Do as little to reduce the torque of the motor as possible (effectively, I believe do nothing to reduce torque), and the extra (even inaudible) dynamics will be heard as finer and finer micro- and macro-dynamics, which means being able to hear more detail, even better transparency and separation, faster transients which allows better differentiation and better decay/tonality, and so on.
When one combines Direct Coupling, Glass Reinforcement and the total torque of the drive system with the elimination of all damping materials (in the classical sense of noise suppressors like Sorbothane and lead) except the plinth itself, one achieves (especially with a Giant plinth which magnifies all these attributes thanks to the Direct Coupling) a level of reproduction which must be heard to be believed, and even then is hard to believe!! This is because the idler-wheel drive system is then unfettered (from noise as well), freed and allowed to accomplish the task to which it is set: spin the record at as precise a 33 1/3 while actually playing a record as it is possible to do. Spinning a perfect speed, one reaps the 10X the information which actually lies encoded in those licorice grooves, while eliminating the one area in which digital media have a musically-significant advantage (over belt-drives anyway): speed stability.
So, I've essentially eliminated damping materials, left the motor to spin utterly unfettered thus maximizing torque, and relied on both motor tuning and Direct Coupling (to the largest plinth practicable) in order to eliminate/reduce noise. Furthermore, I LIKE the original Lenco top-plates, their shape and their knobs, and so by using glass-epoxy to replace damping materials (reinforcement and CLD of actual damping), I have aimed to preserve some of the looks/style/ambiance, while Funkifying a dated design. All of this thinking has been combined in my latest project, as well as a return to some simple fun in design in the Burled Funky Lenco I have just inserted under my "system". Please excuse yet another plinth, last one for a long time promise....except the multi-armed and also-funky Garrard plinth I am planning for myself soon!
Finally, some observations on the Lenco vs Garrard: the Garrard has a "fatter" bass than the Lenco, and sounds more big-hearted and colourful/dramatic as opposed to the apparently more accurate and precise Lenco. But. The RS Labs sound stupendous on the Lenco, but it has one weakness (relative to tonearms which are superb in this respect): the bass seems slightly overdamped (depending on recording). But mount the RS Labs on the Garrard and suddenly this changes, and the RS Labs bass is perfect in every way and all snicks into place with perfection, detail, imaging, dynamics, etc (this with the Denon DL-103"E" anyway). Similarly, some tonearm/cartridge combos simply sound better (within the context of my system) on the Lenco. The more I listen, the more I think I'll mount my RS on the Garrard and leave it there. All this to say, that no matter how superb and high-flying any record spinner, synergy issues will always come along to confuse us (as mysterious phenomena beneath our radar work beneath the surface, forcing us to rely on our ears in order to optimize). So keep an ear out and optimize your respective systems!!
And just in case some want to read between the lines and jump to the conclusion that belt-drive also only need optimization in order to compete: only if you want to improve an inferior system. A properly set-up quality idler-wheel drive is superior in every way, not just some, to their sad belt-drive brethren. As I always say to those who want to preserve their politically-correct philosophy and try to force me to "admit" it is a matter of taste: "Sure, if by matter of taste you mean a great deal more detail, dynamics, bass, imaging, tonality, gestalt and PRaT." Which is why we are now in the $100K belt-drive league (and climbing) as logically, why are such extremes necessary in order to extract such performance, if not the problem of making an inferior system perform up to the heights now being reached with more effectiveness/lesser cost by DDs and idlers?
And btw, idlers are also superior to DDs, as their motors spin at much higher RPMs (roughly 1800 RPM), which means that momentum and torque in this case truly does go a long way to eliminating motor speed imperfections (further eliminated by the flywheel-platters), while DDs must depend on complex circuits and electronic tricks to try to eliminate the relatively much-amplified motor imperfections (since they spin at only 33 1/3, being directly driven, thus making the imperfections - all physical systems are imperfect - much more audible). The problem at these very low revolutions is that quartz-locking becomes audible, leading to an unnatural sound very much like that of digital media, dynamically constrained relative to idlers, and dry relative to belt-drives. Idlers are the current champions in terms of superiority of drive systems in the here and now. Vive la Idler-Wheel!! Have a Merry Idler Christmas!!!
