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

Could use some input from the experienced high end record spinners here....

Context: VPI Classic 3/JMW 10.5 metal arm (damped w oil)/ZYX R100H --> Audio Note ANS2 xformer (low gain setting) --> Jasmine/Mockingbird modded LP2.5 DU active phono stage on MM 47kohms setting... anti skate off.

Recently switched cartridge over from my Audio Technica ART 9 cart to this ZYX R100H to check it out (bought ’low hours’ from a well reputed A-gonner). On some records, am hearing an occasional distortion in the vocals and mid-upper piano range... usually on transients of increasing volume. I first thought it is mostly at the 1st half of the record... but it seems like it happens throughout the sides of records where it happens (...I know the VPI jig sets minimum tracking error at end of sides). Seems to happen on records that play a little ’louder’... as opposed to audiophile records where volume levels are lower.

Checked ZYX alignment using the VPI jig couple times... am right on. Tracking at 1.9 grams, VTA level. Azimuth good via the balance beam pole on headshell. Tried different tracking forces - up to 2.1 grams, raised and lowered VTA - still distorts. Using Zerostat/CF brush on record, and Zerodust on the cart tip. Record washed with Okki Nokki. Very good hygiene I think.

As an experiment, I removed the AN transformer, and ran the Jasmine in MC mode at 100 ohms loading, and the distortion seems to have lessened greatly. Could the AN transformer be overloading the MM input at the phono stage? But then why just distortion on transients?? Many other loud passages do not distort.

By the way, I have no such trouble in 200-300 hrs with the ART 9 cartridge... just pure musi, clean and gorgeous... just hearing this with the ZYX.


Thanks in advance...

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no i am now determining that it isn’t electrically overloading

the cartridge distorts at the same points on the same records using all step-up and amplification methods

the zyx is definitely not tracking properly or is somehow damaged

i have used the same vpi arm jig set up procedure for ART 9, Koetsu and Zu Denon 103 - the other carts don’t distort

Zyx being sent to Soundsmith for evaluation...
Have you actually looked at the stylus to be sure it is clean?

They sell "60x magnifiers" on ebay for less than $10 and I recommend one to everyone with a turntable.
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...