Distortion mystery -- MC cart mistracking? / transformer / head amp input saturation??

this is an interesting issue. I am very alert to distortion and will study it until i figure it out. (OCD for me). I have found that the first culprit usually is gunk on the cartridge which you indicated you checked. If you have a good magnifying glass i would take a good look at the diamond to make sure its clean and not damaged. I have seen a small amount of gunk on the stylus cause the issue. Magic eraser usually good for it. I have seen a worn/damaged stylus will cause some distortion that is hard to troubleshoot.

You have seemed to cover most of the items that typically make sense, there is an issue with resonance that i have heard can cause this type of issue though i have never experienced it.

The gain/loading can affect the clarity but i find that is not record specific but more of tone related (ie cymbals or the highs get tinny, etc) and happens on all records that have similar tones

Let us know what Soundsmith says. I have been using ZYX a long time and have found them to be excellent trackers once zeroed in on vtf and vta

Peter Ledermann at Soundsmith called me upon receiving my Zyx, and he said the cartridge looks fine... minimal wear on the stylus, stylus is clean, suspension looks fine. He then asked about my setup. When I said I was not using the VPI JMW arm anti-skate gizmo, he emphatically said that was the problem causing the distortion. He said some carts like the Zyx (and his own SS carts too, evidently) really need anti-skate to track properly... and to read and carefully follow his very lengthy and specific instructions on his website regarding setting AS in general, and setting AS specifically for the VPI unipivot arms. So he is sending the Zyx back to me.

In the meantime I have spent a lot of time last couple days learning/reading and setting up AS on the table/arm ... of course Peter’s view on AS is diametrically opposed to Harry W’s. I have read a ton about this now on the various boards and there are clearly 2 fervent camps, Peter’s says gotta have it, Harry’s says no need, basically. Anyhow, following Peter’s instructions leads one to dial in A LOT of AS into the JMW arm. A LOT! I had to buy several metal washers to mount on the AS lever arm to slow the tonearm from skating inside hard, then the AS nylon string pulled so hard on the unipivot that it tilted the arm, causing an azimuth issue. So then, readjust the eccentric counterweight to offset the skewed azimuth caused by the anti skate. Jesus.

Alas, all is dialed in - at this point not using the Zyx yet as it is still in transit back from Soundsmith. But with my Koetsu and ART9, with the AS dialed in ’properly’ per Peter L, I would say things sound great. But then again, with these two carts, things sounded great before too, as these were problem free carts, unlike the Zyx which distorts. Will need to listen more and more critically to see if I prefer which camp of AS.

Zyx will be back in a few days... will try it with the AS dialed in. Hopefully it makes a difference.

Been there....you can drive yourself crazy with this stuff. I first thought it was alignment, so I got the Mint mirror protractor. It helped a little but did not solve the issue. I then went down the AS road and bought the Telarc OmniDisc for the test tracks. That was another minimal improvement but the mistracking on hotter passages (especially on inner grooves) remained.

I truly wish you luck here, but seeing as you already have the ART9, I'd mount it up and move on...

jblnut

Hi,
While I have no experience with the VPI tonearm, I've owned a ZYX Airy 3 (.24 mV output) and used  both with a Moerch DP-6 (13 g armwand) and with a Siggwan tonearm.  While it benefits from a little bit of antiskating force, the amount is close to the MINIMUM possible with both arms.  Further increasing anti-skating with the ZYX Airy 3 has a very negative effective on the sound.
It is puzzling (particularly since you've described your careful troubleshooting) that you need a lot of anti-skating force using Peter Ledermann's method, which (as you know) is to cue down the tonearm-stylus in the leadout area in between leadout grooves, and adjust anti-skate so arm moves very little or very slowly inward.
Good luck in sorting this out.
Harvey