Well that's definitely a wealth of knowledge posted by
analogsurviver.
The Koetsu/Graham combination I run doesn't have any resonance issues -- it's a superb pairing. But as I listen, I'm staring down the throats of gigantic 15-inch 96dB/Watt woofers that cover everything below 1.1kHz, and I listen loud, so any small subsonic energy that gets through (including stuff on the record itself) is going to be visible. On most records, the woofers stay quite "still".
I did get to try the Technics EPA 500 (dynamic damping like the EPA 100) on my old SOTA several years back. No, I didn't do the extreme setup, and the arm wand it had was a very marginal match for my Ortofon Kontrapunkt c at the time, but it still sounded extremely nice -- at least on par with the Fidelity Research FR64fx I was using. I should've bought the damn thing just to have it.
I should have written the exact description of the Technics B500 base, EPA-501H, EPA-501G, EPA-501M, EPA-501E, EPA-501P, ...
http://www.vinylengine.com/library/technics/epa-500.shtml
there are six wands in the series, 5 for normal 1/2" mount, one for T4P P-Mount cartridges. For various cartridge mass/compliance combinations - BUT ALL WITH FIXED ANTIRESONATOR FREQUENCIES AND Qs . It is not perfectly adjustable as with EPA-100 , EPA 100MK2 ( by far the best of the bunch - about triple the price of its siblings ) or EPA-250
http://www.vinylengine.com/library/technics/epa-250.shtml
( which is also part of the EPA-500 system, fitting the B-500 base and sporting S- arm tube, removable IEC headshell and adjustable frequency ( and Q ? ) of the antiresonator ). The most common EPA 500 wand is EPA-501H ( which I own ) - which was a perfect match for the Benz MC Reference some 15 years ago ( pre - Lukaschek times, when the compliance was higher ) - but it usually pairs well with a cart of lower mass and higher compliance. All 500 antiresonators are set to the frequency approx 10 Hz ( except E, which is for highest compliance carts, which require for resonant frequency of 10 Hz zero - or even negative - tonarm effective mass, therefore antiresonator is set to a frequency that is practical in such cases - around 7 Hz ). EPA-501H was the want supplied by default as the "EPA-500" tonearm - and other, much rarer wands may in today*s market burn a larger hole in your pocket than ( B500+EPA501H = EPA 500 ) would.
EPA 500 series is the worst sounding of all EPAs with antiresonator - due to structural resonances within the audio band. But it is possible to DIY them out, bringing the arm(s) to an entirely different level.
Koetsu/Graham is no different in fundamental cartridge suspension compliance/tonearm + cartridge effective mass resonance ( ideally at 10 Hz ) than any of the normal arms - it is no match for the properly adjusted/matched EPAs. Once heard the effect of amelioration - or, in really good cases, complete elimination of - that fundamental "10 Hz resonance", it is difficult to go back to anything that does not allow for its suppression - regardless how good it might be otherwise.
With any of the methods that bring the fundamental resonance close to zero, the woofers will stand "still" ; however, the lower the frequency of this (even compensated for ) resonance, the higher will be the effects of the warps. The only system known to me that does succeed in overcoming this almost-taken-for-granted weakness of the vinyl playback is Transcriptors Vestigal arm ( as the first that did it ) - or, as I have put it upon first seeing/working with it "finally a well executed Vestigal " - the Versa Dynamics TURNTABLE SYSTEM. Both of these arms employ extremely low effective length in vertical sense ( I doubt you can mount the Koetsu on Versa - not enough room for connectors due to long(ish) cartridge body ) - but only if and when used with very low mass cartridges with high compliance. The reason is the little known and even less understood term of SEESAW FREQUENCY - which is the frequency at which the tonearm fitted with cartridge set to track at zero tracking force oscillates if excited from the resting position. With any normal length arm ( approx 8 inches or more ) , the seesaw frequency will be around 1-2 Hz - which is WAY below the fundamental system resonance of around 10 Hz. That means any record warps below 10 Hz must be dealt with exclusively by the stylus suspension - as the cart/arm can no longer follow these. Vestigal or Versa - with a LIGHT cartridge (say up to 3 g, plastic hardware used to screw the thing together ) with enough compliance to allow for fundamental 10Hz (or lower ) resonance will be completely devoid of "woofer dance" ; when I first measured Versa + Ortofon OM Super ( any decent stylus from the series will do, I used OM20), I could not believe my eyes - for the first time, the output of the turntable looked like the output from the signal generator. No aberrations typical for conventional cart/tonearm combos - whatsoever. Substituting Ortofon OM20 (almost bottom of the line, extremely light high compliance cart ) for MC-7500 (then top of the line, but heavy and low compliance cart ) had so devastatingly negative results I really felt sorry for the friend - it would put me, as it did him, on the brink of open crying.
For those not familiar with either Vestigal or Versa - both would only work properly with a totally flat record. That*s WHY I called the Versa "finally well made Vestigal" - as Versa is a TURNTABLE SYSTEM ( TT + arm), neither of which is (or should be/have been ) available separately. The key element and fundamental condition that has to be met is record flatness - as low effective lengths like these two ( LESS than a typical IEC/SME headshell ) create far too high error in VTA over warps of normal records. It can also be heard as "wow" - dullness as the cart/arm is lifted from "flat" to "peak", then sharpness when it descends from the "peak" back down to flat. Versa incorporates vacuum record suction system - and logic built into the electronics of the turntable prevents rotation of the turntable itself unless the satisfactory vacuum seal has been achieved in the first place. All that remains of the vertical motion of the stylus/cartridge/arm (besides modulation of the grove, of course ) is the discrepancy of the thickness of the vinyl record(s) itself - but that is inherent flaw of any real pressed vinyl record copy.
I can not afford the Versa - but have been able to reproduce almost the same result using (heavily modified) Vestigal/low mass high compliance cart with vacuum suction systems on various turntables.
