Hi Mike, thanks for the tweak suggestions. Pierre, the designer/builder of my 100-watt SS amp, had once very convincingly demonstrated the effects of the degaussing tweak, but these machines were no longer available (I think sold by Monarchy at the time), great to know there's a cheap and available alternative! Thanks as well for the tip on the Rat Shack tool, I'll look for it.
On the tonearm/cartridge front, more news: in fact, none of the vintage tonearms I've tried match the JMW, Morch or RS-A1 tonearms, due principally, I believe, to the suppression of internal resonances, and in some cases also the headshell resonances. The Sonus has a flimsy plastic headshell to minimize mass, and no internal damping at all. Nevertheless, the Sonus/Grado Master came close to the JMW/Grado Master, but with other cartridges the gap was rather large, showing that Grados like low mass, regardless of specs. The real advantage of vintage low-mass tonearms (excepting perhaps the lowest-mass Morch) is that they track the most difficult warps with the utmost ease (no momentum to create the ski-jump effect), and so enlarge the collection and reduce problems. They also save on suspension and stylus wear. I won't give up on the Sonus yet though, as I'll try the fab vintage Satin MC (a gorgeous sound like the Grados, but aimed more specifically at stringed instruments) I have on it next to see what's what.
I had tried the Audio Technica ATP-12 tonearm, a superbly well-built higher-mass professional tonearm with no provision for anti-skating (but seems to work perfectly well nevertheless), but better-built overall than either the AT-1009 or AT-1005 MKII. It sounded great with the Ortofon Jubilee (at 10 times the price!) and a variety of other cartridges I tried. But, compared with the JMW 10.5, there was a slight hardness/brightness, those tonearm resonances again. But it came surprisingly close! All this on my new Reference Lenco of course, I'll have tio try the Rega RB-300 and RB-250 tonearms again to see how they measure up in overall performance now that my Reference has reached new heights.
More on the Jubilee: properly set-up - and this means on a large idler-wheel drive with its clear superiority in terms of PRaT, gestalt and SLAM and transient speed to every other system so far (though we're working on optimizing DDs) - it is a stunning high-end cartridge, which at the price (just under $2K) is a steal, considering its competition lies in the <$8K league. The only high-end MC I've heard so far which matches and beats the incredible Denon DL-103 and variants which so far - for musical power and togetherness - have been King of the MC Hill. I had set up the Denon DL-103"E" (retipped by phonophono in Berlin) on the JMW nad was as always seduced by the musical power, intensity, and togetherness. But when I switched back to the Jubilee, there was all that and more, and even more musical power! As always when setting up cartridges and tonearms on belt-drives, a true idea of a given cartridge's character and performance escapes us, as the belt-drives' various speed instabilites - MOST clearly audible in the relative lack of bass when compared with idler-wheel drive, which itself is the simplest and most evident proof of the inability of belt-drives to deal with stylus force drag and so achieve true speed stability (as opposed to bogus/not real-world speed stability reached by cooking the testing books via biased testing) - cause brightness and poor tracking, among other phenomena such as loss of transient speed and timing. Take the Ortofon Jubilee and mount it on a Lenco/JMW and Bingo!-Presto! it becomes a Denon for musical power and togetherness, and as well preserves its leading-class detail, bass and overall clarity. Also, being King of the Hill when it comes to bass, its results in this one area is truly awesome when mounted to an awesome idler-wheel drive!!
Given all that, I'm still experimenting with various viable alternatives to the Mighty JMW/Ortofon Jubilee pairing, and by this I mean equal but different in overall performance and musical effectiveness. I'm hoping either a re-wired Rega RB-250/Grado Master, or the MAS 282/Grado Master pairing will do the trick.
Tomorrow, in a truly scary high-end system, I'll be setting up a Lenco/Dynavector 507 MKII/Dynavector 17D MKIII, for the previous owner of the Oracle Delphi MKIV/SME V/Dyna XX-1 VdH, already handily outperformed by the Giant Direct Coupled Garrard 401/SME/Dyna XX-1. It'll be interesting to see how the two - Lenco and Garrard - sound compared to each other in such a high-calibre system!! The Oracle is already moot :-)!! Have fun all!!