Mounting a Jelco Tonearm

I'd post this question on Audio Karma or Vinyl Engine, where there are larger DIY communities. I haven't mounted a Jelco, but have thoroughly read up on the process as it applies to Thorens tables. This is the first I've read of any discrepancies with the published length specs. However, when it comes to their effective mass, it's a mystery, no one agrees.

Whether a cartridge sits in the middle of the hesdshell is irrelevant. What is important is that it can align to both null points on a two-point protractor, or in your case, align to the grid with the arm/spindle jig in position. Carts and stylus' come in various lengths, so focusing on the middle of the headshell will only lead you to the mad house.

Thanks for the info, I'll let my friend know this

Setting up a pickup arm may be a tricky process, but it's not exactly rocket science. helomech is correct - the goal is not to get the cartridge in the middle of the headshell. There's no reason a Dennesen Soundtracktor can't be used to set the pivot-to-spindle distance for the Jelco.

To really dial in the final alignment, I like a mirrored gauge, such as the Wallytractor.

Does the Jelco come with a drilling/marking template?

When I mounted my Dynavector 501 as per the specified pivot to spindle distance, the cartridge mounted so close to the back of the head shell, it made it difficult to connect the cartridge leads. I made a new arm board, moving the pivot to spindle distance ( I think it was about 5 mm). This allowed easier connection of the leads, and the cartridge overhang set up just as well on my Mint LP Best Tractor set up tool.

It sounds as good, or better than it ever did, so that leads me to believe pivot to spindle distance isn't as critical you may think, as long as overhang can be dialed in correctly. That's just my experience, someone else may have better information, and will set us both straight.

Regards,
Dan

What kind of music are you listening to @islandmandan ?

My 12" Jelco overhang is meant to be 15mm but it's about 10mm with no discernable negative effect. The 750L comes with a template so not sure why this is even an issue other than the feeling that the bolts should be in center of slots.

Schubert, I have a fairly broad range of musical interests, chamber music, symphonic, mostly mainstream jazz (Coltrane, Monk, Miles, Bill Evans, etc; blues and some R'nR.

I love good music, as long as it's what I consider good. Not big on rap or opera (although I do listen to Wagner's Ring Cycle on pristine vinyl on occasion). I'm guessing you have an affinity for Schubert?

Regards,
Dan 

Yes, he led me towards classical music which has done more for me than anything else of human origin   in my life .
I'm a bit  ashamed I was so bold . when I  joined A'gon I thought there was nothing but R&R fans on here so I acted out .

Thanks for all of your responses everyone, my friend has figured it all out, happy and a healthy New Year to all you A'goners.  May we all have a great year.  Happy Listening!!!

Lou,  So are you going to tell us Jelco owner what the conclusion was, or are we gonna wonder if our arms are installed correctly?

I wouldn't be able to tell you if your arms are installed correctly, I'm certainly no authority on the subject, that is why I was asking the question for a friend.  If it sounds good, I'm sure you have it set up correctly.

My friend replied to me that he got his turntable geometry worked out and that it's amazing when it's right because everything just snaps into place.  He then sent me a few pics of his TT which is a Technics SP25 in a custom plinth.