Distortion in loud passages

[orangeshasta]

Hi all,

I'm somewhat new to the vinyl world, at least in the realm of hi-fi. A couple months ago, I got a great deal on a used music hall mmf-5 table with an upgraded Adcom crosscoil cartridge. The cartridge has definitely seen some use, but the previous owner seemed to think it still had a fair amount of life left in it (he demo'd it for me with his setup, and I concurred).
Anyway, I've been noticing a problem when I play records - in any loud passages, the sound distorts...it sounds like something is saturating, I guess. I thought it might have been my record selection, because most of what I play are the "dollar bin" variety from used record stores, or those given to me by people getting rid of their collections. However, I just picked up a virgin copy of the new Robert Plant/Alison Krauss album (which, by the way, has a MUCH better mastering job than the over-compressed catastrophe that is the CD) - and I noticed the same problem with that.
Any ideas what might be causing this? I'm playing it through the phono preamp built-in to my Kenwood home theater receiver, so might that be the culprit? Or maybe there's an issue with the stylus?
Any ideas would be much appreciated, thanks!

[orangeshasta]

Also, this is probably relevant - I do clean all my new acquisitions before playback on a vacuum RCM, and before each time I play them I give them a dry brushing. So I don't think it's an issue of dirty records.

[arnoldc]

I would check the VTF, SRA and Azimuth

[Mitch Alsup]

First make sure the turn table platter is dead flat and level (use a spirit level or similar).
Second, make sure (e.g. measure it) the tracking force is correct.
Third, set any anti-skating device to null out the skating force.
Forth, make sure the needle is clean
Fifth, make sure the record itself is clean

[orangeshasta]

Hey, thanks for the ideas - I should have thought of adjusting things.

I then have another question - what tools/techniques would people recommend for adjusting things like the azimuth and the SRA (VTF seems pretty self-explanatory)? I've done a bit of searching, and it seems as though a lot of the tools out there might be unnecessarily expensive ($75 test records, $250 alignment tools, etc.).

[arnoldc]

You need to have a cartridge alignment tool. You have to understand overhang, effective lenght, etc.

If you're serious about analog, you have learn all these. However, being DIY in nature, this post is somewhat off-topic and may not get responses. You should go to to other forums such as Vinyl Engine or Audio Asylum. You can start here - http://www.audioasylum.com/cgi/d.pl?...faq.html#vinyl

[kevinkr]

Arnold's advice to post on vinyl engine is a good one, and will get you a lot of good information.

If you have not set the tracking force on this table since you brought it home you should do this now. While it would be nice to use a tracking force gauge the arm should provide sufficient accuracy on its own to get you in the ball park. Set the tracking force near the maximum value recommended by Adcom - record wear and distortion are usually caused by low tracking force rather than the reverse.

Next set the anti-skating force to same value as you have set the tracking force.

As a quick check on VTA most USA cartridge manufacturers recommend you start with the front cartridge face perpendicular to the record surface.

Setting overhang/effective length requires a stylus protractor or sometimes a TT manufacturer supplied gauge, temporarily you probably can download the Vinyl Engine protractor template along with the directions to use it. (Verify printer is scaling it properly before use.)

I tinker a lot with my bodged Thorens 125 /SME 3009 set up (plus 35yrs of playing vinyl on my own gear.. )

All of the resources you need are available on line, and a lot of the specialty items are available cheaply on eBay.

[orangeshasta]

Thanks for your responses - especially the Vinyl Engine reference, I hadn't stumbled upon them yet. I guess I should have asked my question differently - I was looking for any do-it-yourself alternatives to the expensive protractors and whatnot. But, it looks like the templates that Vinyl Engine has are exactly what I'm looking for!
Thanks much for your input.

-Bob

[kevinkr]

Originally posted by orangeshasta
Thanks for your responses - especially the Vinyl Engine reference, I hadn't stumbled upon them yet. I guess I should have asked my question differently - I was looking for any do-it-yourself alternatives to the expensive protractors and whatnot. But, it looks like the templates that Vinyl Engine has are exactly what I'm looking for!
Thanks much for your input.

-Bob

Hi Bob,
The other things need to be looked at carefully too, assuming that you haven't already, and assuming the table was correctly setup for the demo, the overhang is likely the only thing that did not shift when you moved the table. (Depending on the arm it may have also shifted, but serious mis-adjustment usually results in the most noticeable distortion near the end of the disk.)

One other thing to be sure of is that your phono pre-amplifier is not being overloaded by this cartridge. Finally it is not impossible that the cartridge was just on the edge of acceptable performance when you heard it, and is now showing its age.