possible help for stylusless Sonus owners

[wualta]

No, I haven't found a cheap source of Blue Label or Gold Blue or Super Blue styli. I wish. No, just an observation based on looking, which is to say, the pole-piece "mouth" of the Sonus is pretty much the same one that designer Peter Pritchard had been using since the latter days of the ADC Bricks, ca. 1970.

You've already guessed where this is going if you're an ADC fan at all, and the answer is yes, you can indeed use an XLM stylus on a Sonus standard-mount body. With some caveats.

The fit is very tight. Some of the early non-carbon-fiber-reinforced stylus grips may crack. This is especially true of aftermarket styli. You must be careful of the cantilever as you apply force to press/slide/snap the stylus over the Sonus body.

The bodies of most Soni are around 150 mH, which puts them lower than most ADC XLM-style bodies. In fact, I've never found an XLM that low.

The point is, 150mH puts you in the Mk I or Mk II stylus category, and these styli are becoming rare. A Mk III would fit and make sound, but it would be quite noticeably bright.

The closest match to the Sonus body would actually be the original XLM stylus, if you can find one.

To get the flattest response with a Mk I or Mk II (not Mk II Improved), you'll have to resort to lowering the resistance loading or turning the treble down a little. Of course, you might just like it as-is, so try it both ways if you have the option. If you're adventurous and feel confident you can correct the treble rise by ear, try a ZLM Improved or XT-IV stylus, and be prepared for a lower output level than when these styli are used in their "native" or "home" bodies.

These days, this is about the only way to put a Pritchard stylus in your Pritchard Sonus for reasonable money.

 

[dlaloum]

:thmbsp: thank you!

 

[wualta]

Just taking advantage of Pritchard's frightening level of consistency over the decades he was in the cartridge-making business.

The Sonus bodies don't appear to have the thin metal cylinder that lined the "throats" of the XLMs. I've always guessed that this cylinder was the eddy-current damper that constituted what the marketing copy for the XLM called Controlled Electrodynamic Damping.

Maybe the Sonus styli didn't need it or didn't want it (they do show strong ringing at resonance in contemporary tests). So here's everyone's chance to hear undamped XLM styli.

I should point out that no one is guaranteed to like the results of this still- experimental setup. All I can promise you is that without madly changing the VTA or trimming any plastic bits, you can get the wiggly end of an XLM/VLM/QLM's cantilever near enough to the pole pieces of a Sonus body to play music, simply because the Sonus body is so similar in shape and function to the XLM's body.

But it does sound good to me.