help with arm types


can anyone tell me the different arm types available, and their advantages/disadvantages?

i have a expressimo rega 250 arm, and am considering an upgrade (along with my cartridge). i know the arm/cartridge synergy is important, and want to make the right choice. the cartridges on my short list are an urushi or a shelter 501 or 901.

priorities include ease of use and "set it/forget it".

thanks,
steve
128x128dennis_the_menace
Dennis, I'd add to what Twl wrote except that I can't. As usual he summarized everything very well.

That's a pretty nice cartridge shortlist. They're all relatively low in compliance, keep that in mind when thinking about arm types. Check my system for one combo that works very well. I'm sure the higher model arms from OL would work even better.

"Set it and forget it"? Did you want the digital forum?!
hey doug... i actually consider my expressimo/denon 103r "set it, and forget it"... I spent a fair amount of time being picky making sure everything was right, and i've checked everything once since then, and other than VTA, i haven't had to adjust anything. i re-checked the tracking force, arm placement, cartridge angle, leveling, etc. once since my initial setup, and nothing really needed adjusting.

of course everything sounded great, but i thought that maybe my hearing wasn't sensitive enough, what did i know?

i then got nervous that this couldn't be right, that setting up and maintaining the turntable had to be harder, and i bought the "test" LP (forgetting the name off the top of my head... HiFi magazine puts it out?), that tests everything from phase, to tracking, and all tested really well. i was able to get through all but one of the tracking tests... and passed all the other tests with flying colors.
DtM,

Just joking about the digital thing of course, though with such a nice rig you already knew that! One of the good things about the OL arms, much like yours, is that there AREN'T a lot of dials and buttons to fuss with. Get the setup right, lock it down, play music. If you go with OL buy from a reputable dealer. OL has occasional Q/C lapses so you want to be able to return if necessary.

The HFN test record is kind of fun to play with, but not all that useful in the end. Your ears quickly become a better judge of whether your setup is right or not. FWIW my 265/OL Silver/Shelter 901 perform about the same as yours: no real buzzing until track 4, pass all other tests, horizontal resonance about 10.5Hz, vertical resonance about 11 Hz but almost nonexistent.

Last week I had to realign my arm/cart because a certain partner apparently nudged the armboard a mm or so. All of a sudden I was hearing inner groove distortion on records that never had it before. So I dragged out the protractor, the magnifier, the shiny bright light, the muttered curses... When I spun up the first side we listened for a few minutes and he asked, "Did you change the antiskate setting?" Sure enough, I'd dropped it to zero to use the protractor and forgot to reset it. Who needs test records?!
I would just like to say a great big 'thank you' to Tom for giving a brief but concise summary of the different arm types and their respective strengths and weaknesses.

I was just wondering whether Tom or any other members hee could add perhaps a short list of any applicable do's and dont's for each arm type, e.g. I've heard it mentioned that unipivots should not be installed on tables with a suspended design, etc.