Help with vinyl frustration?


I guess it is my turn for some frustration with set up. I've read posts about it, but haven't encountered it until now.
I bought a new ScoutMaster about 4-5 months ago. I installed a brand new Dynavector 20XL which is supposedly a good match. However I have never sensed the magic that I believe this TT is capable of providing. I have checked and rechecked all calibrations. I have been up and down the scale of VTF/VTA. The problem persists.
The problem is that on certain songs on certain albums the vocals and upper mids/mid bass have a slight distortion. This might happen on one song and the next song sounds fine. This began just about the time of break in for the cartridge, maybe 50-75 hrs. As I said, I have checked and rechecked. I can find nothing wrong. I get the feeling that it is a very minor thing. Then sometimes I wonder if it is the cart itself?
I only notice this on classic rock albums which is what I play the most. I haven't heard this on classical albums. Which causes me to ask, Am I seeing to deeply into a poorly recorded record? But if so, why only certain songs on the album? And always the same place; vocals? This doesn't seem like an acceptable answer. Certainly if it is I guess I shouldn't have sold my MMF-7. However the SM kills the 7 on classical.

Anyone with any suggestions?
128x128artemus_5
I'm not familiar with your cartridge, other than its name. However, I wonder if you have too much output for your phono stage. What is your preamp/phono stage and what is the rated output of the cartridge? If the distortion seems to be happening with "louder" music or passages, it could be an overload of the preamp's line stage from the RIAA output. I had exactly this problem with an ARC PH5 phono stage and a lesser preamp. When I upgraded to a VTL preamp that had tons more dynamic range, the problem went away in a way that seemed like a miracle. An alternative would have been to have ARC pad down the input to the phono stage (terminals are factory provided for that). I suppose it could have been done in a quicker/dirtier way with an atenuated cable of some sort, but I think would do your excellent phono setup a disservice.
Cmo
I have used the ortofon alignment tool (2 point) and the VPI (1 point). didn't seem to make any difference. Record proximity IE end of record makes no difference. It might happen anywhere on the record so i don't think it is anti skate, but will try anything at this point.

Pscialli & Cmo
It does seem to happen moreso on more "congested" songs rather than simple passages. AAMOF, simple passages might sound great in the same song. This makes me wonder about overload. Actually that is the exact word I would use to describe the sound that i am hearing. So you may be right. I can turn down the output on the phono stage via the output (volume) pots on the Wright phono stage. Thanks for the suggestion. Don't know why I didn't think of that. Duh

Onhwy61 & Hals den. Thanks. I've thought about the same thing but it seems odd that it is sporadic across the album. You may be right but I hope you're wrong.
That was it. Overload. That was the word that kept running through my mind when I heard it but I never thought about the phono preamp overloading. Duh! it was turned down but not enough. The Wright has 65db gain w/o the 1:10 tranny. I've got it turned down as low as it will go now and the distortion has gone. At least it has on the 2 of the songs that were leading offenders.
Thanks a bunch
it sounds like a cartridge problem to me too. an alignment issue would be the first place to check.
Distortion can also be aggravated by too little vertical tracking force (VTF). I found this to be the case with a couple of cartridges I owned. In both cases, I was using an inaccurate measuring device. Once I got a more accurate stylus force gauge I was able to clear this up significantly. Finally, skating can cause distortion, but you'll typically hear it in a single channel when that's the case. Since it seems like overloading correction has solved the issue, this post may be moot, but hopefully still useful.