Tracking down cause of distortion on vinyl


Hi all -

Recently LPs on my modest system (Technics SL-1200 w/ KAB Groovemaster) have been sounding off - kind of thin and distorted, especially on loud tracks or passages. The stylus on my cart was destroyed by someone in the house, and I had to replace it with a JICO back in February. The JICO was fine at first (although the suspension was not as good as the original - did not track as well and needed higher force), but I have heard they have quality control issues and suspect that is the cause. But how can I actually verify this?

Is it worth getting a test LP (I hear mixed opinions on the worth of these) - is there anything typically there that would isolate mistracking, say, as the cause?

I love the cartridge, but don't love the idea of ponying up for another questionable stylus (assuming I'm unlikely to get any credit on it now), if that is indeed the problem.

Also, is it true that if it is mistracking badly it is damaging any vinyl I put on?
dmsantini
Hi Richard,

You obviously know way, way more about this stuff than I do. The KAB Groovemaster was one of Stanton's DJ carts, fitted by Kevin @ KAB with a stylus along the lines of a Pickering D3000. That stylus was destroyed by someone accidentally (I went to play a record one day, and it was bent completely sideways).

The JICO imitation stylus sounded perfectly good for the first few months, so I don't think the diamond was off-alignment in the beginning. However, there were immediate differences from the original - with the JICO, records were much more likely to skip from anyone walking around the room, lead-groove skip became common, etc.

I suppose it's possible that whatever inferior material they used has caused the suspension to sag, changing the VTA of the diamond. I did mess with adjusting that some, and it did seem to help a little bit, but just a little.

Right now I'm playing with a Grado Gold I got from someone on here, trying to get that aligned perfectly. First attempt was not great, second attempt pretty good, but I think there's still room for improvement. But I fear that whatever mistracking the old cart was doing did do some damage to some records (comparing a few that I know I listened to and heard distortion with the old cartridge to records that I did not play at all during that period), so I'm loath to do much more testing with that needle.
"with the JICO, records were much more likely to skip from anyone walking around the room, lead-groove skip became common, etc."

That's the key sentence. The compliance of the new assembly is different than the original. It's like putting the wrong shocks on a car. Read on...

http://www.theanalogdept.com/cartridge___arm_matching.htm
http://www.vinylengine.com/cartridge_database.php
http://www.soundfountain.com/amb/ttcartridge.html

Setting up a phono cartridge can be a pain in the butt, but must be taken seriously and done properly. If you decide to purchase a new cartridge, make sure it will match well with your arm. Hopefully, you know the overhang spec and have a way to measure it.
For $50 at least get yourself an AT30 and see if the problem is the replacement stylus or otherwise.