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

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

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

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.

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

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.

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...

Ok just re read the entiler post and the other guys could be on the right track with the over loading. but also look at Load of the cart as well.

I didn’t read every post here so if I’m repeating sorry. But I has a similar situation and like you when I added more load on the cart is seemed to go away after some talk with my audiophile club friends they recommend more loading. I think you are not loading your new cart enough so you get some issues especially at higher frequencies. If like you mentioned it’s better at a 100ohm load there is your evidence that more load is what you need. The audionote SUTs do not have much load I was looking at the same SUT you have and it was just not enough load for my VAn Den hul cart I'm sure your looking at a similar situation 

Jjss49, yes, that could very well be a contributing factor to the issue, as 5 cm/sec and 3.54 cm/sec differ by 3 db, **if** the two numbers are defined on a consistent basis.

However that discrepancy, which is commonly seen when comparing cartridge specs, is somewhat ambiguous. In part because the amplitude of a sine wave can be defined on either a peak basis (the maximum amplitude it reaches during any part of each cycle) or on an RMS basis (its amplitude as computed on a root-mean-square basis, which may be thought of as a kind of average value). And for a sine wave 5 cm/sec peak equals 3.54 cm/sec RMS.

For further discussion of this see the posts in the second half of this thread, beginning with the posts dated 7-4-2012.

Regards,
-- Al

Further on this... I have discovered the Zyx cartridges' output is measured at 3.54 cm and the ART 9 output is measured at 5 cm... so measurement standards are in fact quite different.  

So taken at face value, the R100H output is 41% higher than the ART 9, or measured at the higher standard, R100H output is at least 0.68 mv (vs the ART 9 spec'd at 0.5 mv)!

That would explain some input overload at the head amp!!

to dover and almarg

yes you are both quite right... thank you

almarg - my unit is a ANS2 ’H’, thank you so much for your calculations

i had been using the L setting of the ANS2, which in fact provides slightly more gain than the H setting (counter-intuitive, but I am now clear on this) ... my error -- in due course i will try the H setting on the transformer -- the internal impedance of the R100H is somewhere in the middle of the two impedance ranges quoted for the ANS2 settings... I should indeed run the other and see if it cures the ill...

by the stated ANS2 specs the gain is only +/- 2 db in the 2 settings, so not much, on paper at least, but almarg your calcs make it more obvious that into 47k ohms the gain differential is much greater... thus most likely the root cause of my problem - THANK YOU :)

sidebar -- that Mockingbird/Jasmine 2.5 unit is very very nice... punchy, quiet, big stage... plenty of gain of LOMC... incredible value for an active head amp, very glad I tried it after reading A Salvatore’s notes on it...

Dover 4-9-2017
What do you mean by "low gain setting".
The ANS2 has 2 IMPEDANCE settings - L and H.
L is for ultra low internal impedance cartridges and has HIGHER gain.
H is for higher impedance cartridges and has LOWER gain.

+1. Excellent point by Dover.

Also, according to its manual there are two versions of the AN-S2 transformer. The AN-S2/L, which has an input impedance switchable between 3 and 12 ohms, and the AN-S2/H, which has an input impedance switchable between 15 and 60 ohms. Which version is yours?

According to my calculations, and assuming a 47K load on the transformer’s output (as you indicated), the gains of the transformer are as follows:

AN-S2/L at 3 ohms: 42 db
AN-S2/L at 12 ohms: 36 db

AN-S2/H at 15 ohms: 35 db
AN-S2/H at 60 ohms: 29 db

Most of those numbers are MUCH too high for use with a 0.48 mv cartridge. A gain of 20 db would correspond to a voltage multiplication of 10x, which would raise the output of a 0.48 mv cartridge to 4.8 mv, which would be just right for a MM input.

If you have the H version of the transformer the high impedance (60 ohm) setting **might** be ok, depending on the overload margin of your phono stage.

Jjss49 4-8-2017
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.

Sharp transients have substantial high frequency content. RIAA equalization that is present on a recording boosts high frequencies substantially (the boost gradually increasing to about 20 db, or a factor of 10 in voltage, at 20 kHz relative to 1 kHz), while reducing low frequencies substantially (the reduction gradually increasing to about 20 db at 20 Hz, relative to 1 kHz). The opposite equalization occurs in the phono stage during playback. It is therefore quite conceivable that overload distortion is occurring in phono stage circuitry that is "ahead of" its RIAA equalization circuitry, that will only occur as a result of the high frequency content of transients. While not occurring on lower frequencies even though they may be at considerably higher volumes.

As to why this happens with the ZYX but not with the ART9 (which has a similar output rating of 0.5 mv), perhaps the frequency response of the ZYX in the treble region rises a bit, relative to the response of the ART9. Or perhaps the output ratings of the two cartridges are based on somewhat different test conditions (which is not uncommon).

Hope that helps. Regards,
-- Al

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.

You should also consider using magic eraser for cleaning.

I had a similar distorting in the transients and high-volume passages experience myself.  In my situation it was simply too much gain from the phono stage. Looking back, one would think this would be a very easy problem to figure out, but for one reason or another it bewildered me for quite some time! Anyway, a touch less gain, no more  overloading, and problem was solved. This may or may not apply to your scenario exactly, but I thought it may be helpful in someway.

" @sfall  I totally get it that carts change a lot with break in... but this distortion sounds like mistracking or some kind of input overload.... not sure a less-than-broken-in cart would sound this way.... or am I wrong about that? "

It depends on the cart. Some need so much break in they sound defective when new. I mean that literately. If that's the case, putting more hours on it should resolve the issue. But I still recommend you try plugging your TT directly in to your MM phono pre.It will only take a minute. That's how you check for an input overload.

What do you mean by "low gain setting".
The ANS2 has 2 IMPEDANCE settings - L and H.
L is for ultra low internal impedance cartridges and has HIGHER gain.
H is for higher impedance cartridges and has LOWER gain.

According to audio note the H setting is for cartridges with an internal impedance between 4 & 20ohms, L setting is for cartridges 3-12ohms.

If you are using the L setting, try the H setting, it will have less gain and less likely overload the phono stage ( you should be using MM ).

Your cartridge has an output of .48mv and internal impedance of 8 ohms.

@sfall  I totally get it that carts change a lot with break in... but this distortion sounds like mistracking or some kind of input overload.... not sure a less-than-broken-in cart would sound this way.... or am I wrong about that?

It's possible that your new cart is not fully broken in. Phono carts change a lot with break in. More than any other component.

Otherwise, it sounds like you have a bit too much gain. MM is the lowest amount of gain, so you can't do much about it from that end. I believe the H on the ZYX stands for high output. If that's true, plugging you TT directly into your MM input should fix the problem. You won't be doing anything wrong or dangerous to your equipment. MM is the correct setting for a high output MC.

I had almost the exact same issue with two different Transfiguration carts on my Classic 1. I would get occasional distortion (which I think was mistracking) on hotter cuts during difficult passages. I too went to the ART9 and I have never looked back. I am convinced not all carts work well on the VPI arm. The Temper Supreme was astounding most of the time, but you never knew where or when it would trip up and shatter the illusion. The AT is maybe 85-90% as good but never falters. Ever...it tracks superbly.