 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
84.168.186.247
In Reply to: Re: First of all on a Rega TT it is 222mm. posted by zoltarcat on September 17, 2006 at 06:18:38:
Do you mean the bolts are already at the very start of the slots and the cartridge cannot go further back in the slots?Is this particular cartridge so much longer than the others? Not all cartridges are the same length from mounting holes to stylus.
And yes, the Rega plinth are CNC machined so the tolerances are tighter than you could ever measure to double check them.
The Stevenson alignment is correct but who is the protractor from?
Follow Ups:
Yes. That is what I mean. I ned to back the cartridge up slightly and there is no more room to do so. It is a Shure Ultra 500. I have had it aligned by the Baerwald method, using a Soundtraktor. I used the Kwiktrak gauge here. On all my other Planar 3s, this gauge made things sound much better. I want to try it here, but the stylus does not sit exactly in the crossmarks. It is slightly over them. The gauge is aimed directly at the arm pivot. What next?
It's a better alignment than Stevenson's, anyway. However, you will need to angle the cartridge inward slightly in the headshell to increase the offset angle by about 1-degree.Best regards,
John Elison
I no longer have one to measure but I recall that and believe it has been mentioned here before in that original discussion over the alignments methods to use with a Rega arm.Using Baerwald the Shure is exactly the cartirdge you want. IE very long since there is room to move backwards. A very short cartridge doesn't work in the case of Baerwald.
With the Stevenson null points it appears the cartridge is simply too long. if you were to use an original Rega protractor/method it probably wouldn't "fit" either. Tuff luck.
You can't use Pinto parts on a Porsche either! :-)
Cheers!
It has been reported by several people over at the Vinyl Engine that when using certain protractors, a stylus to pivot of 119mm works better, although 222mm is the established correct measurement. I don't know; I'm simply reporting what I read.
I also tried a Stevenson alignment gauge from Vinyl Engine that was meant to work with Regas. I come up with the same result. I still need to back the cartridge up a bit, to get the stylus to sit right on the crossmarks on the grid. There is no more room in the headshell slots to do this. I want to do this right. I have a weird feeling someone will say something here and I will figure it out.
Slot the tonearm mounting hole a couple of millimeters. The base should still cover it.
Before going the Dremmel tool route, are you clear about setting the effectve arm length? This is the length from the horizontal pivot point (as I recall, it is the "X" you mentioned earlier) to the stylus tip. Be sure you cannot get this where you want it before you (very carefully)lengthen the headshell slots with the Dremmel.Then, be sure that you've mounted the arm the proper distance from the spindle center, which you can indeed measure as you've suggested, given the proper tools.
It goes without saying (I hope) that if you can correctly set both effective arm length and pivot to spindle distance, then you are home free.
IF you wind up using a Dremmel, be sure to keep TOTAL control over the grit you'll generate while grinding. It is a royal PITA if you let it get away anywhere near the TT. And, of course, keep the cartridge well away from the work/dust until you've got everything totally clean.
As an alternative, you can use a small file, like a jewler's file; but you still have to control the debris, and you have to be much more careful about twisting the arm while you hold it while filing.
Good luck,
Paul S
The arm is mounted where the manufacturer mounted it.Not all cartridges are of the same dimensions, some are longer some are shorter.
The headshell slots are of a limited length.
Some cartridges may just be too long.
Not everything in analogue hifi "fits" together. If it doesn't fit don't use it.
In this case he can use a different alignment which is not what the arm was designed for but given the length of the cartridge it works.
Dremmel my ass! :-)
Well, you are certainly pointing out the safest alternative, for the average guy.But he wants to use his Ultra 500, and I did lengthen the slots in my own RB300 (with a Dremmel) and it worked out fine.
OTOH, and caveat: I have used such tools professionally for almost 40 years, as part of my profession (builder).
AND, I've known and read posts from many folks who have trashed Rega arms while attempting to "upgrade" them.
SO: all the usual warnings apply.
Not for Klutz.
Best regards,
Paul S
And I think you mean 219mm. Newbies pick up on wrong data real easily. :-)In any case that was hashed out here long before the VE even existed I believe.
It all came about with the popularity of the Wally Tractor. Because he had to assume a pivot to spindle distance of 222mm with a Rega arm he choose the effective length according to Baerwald that correspsonds with that distance. But he didn't realize the Rega arm was not designed with Baerwald geometry in mind.
Unfortunately it (Baerwald null points) places the cartridge at the very far end of the headshell slots to meet the requirements of the effective length, IE pivot to spindle distance plus overhang.
I pointed this out to Wally in 1998 in person when we could not align a Transfiguration Spirit on a Rega arm mounted on a Basis TT using one of his first WT. He thought the arm was not properly mounted. It was, at 222mm as specified by Rega. This particualr cartridge has a shorter than normal stylus to mounting hole center distance but is not the only cartridge that does not work.
So that's the story why if you move the arm to 219-220mm you have more "play room" for adjusting the overhang when using the Baerwald null points.
The problem is not the Rega arm of the mounting dimensions from Rega it is the concept of aligning the cartridge "on that arm" using the Baerwald null points. It gets even worse with Loefgren.
But the above person is using a Stevenson protractor which is "very" close to the null points the Rega arms were "probably" designed around. Rega does not reveal any info other than mounting distance. However if one solves the equation to determine eff length based on mounting distance and null points and assumes 222mm and the null points of 60.5 and 117mm The resulting effective length of 237mm is what it actually is if measured. Hence comes also the assumption the overhang is 15mm, IE 222 + 15 = 237mm effective length.
What doesn't make sense above is the fact he is using the "correct" protractor and has one cartridge that doesn't "fit" whereas others do.
Probably operatoritis. :-)
Cheers!
Yes, I did mean 219mm, rather than 119mm. However, I would like to see a n00b mount one at 119mm. It would be interesting because I have never seen a tonearm mounted in a platter. LOLI am reminded of a guy who had a Grado wooden body cartridge. He posted here that it sounded thin, etc. I suggested that he tip the cartridge back. I meant that he might try changing the VTA by lowering the post of the tonearm slightly, of course. Some Grados sound better that way. Anyway, he later sent me an e-mail because his cartridge leads wouldn't reach anymore. He was lucky that they wouldn't because he had turned the cartridge around!
You are probably right, but I am at a point where I am less concerned about all that than I was at one time. People need to think, and if they don't, is that our problem?Fortunately, the member asking the question in this thread is a thinker. We really don't have to worry about him at all.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
