How to set SRA after determining true vertical?

Neil, how did you determine the 4mm => 1 degree? I'm not disputing it, just curious how you measured it.

Got it, Neil. The calculation makes perfect sense. Guess I was expecting that you had marked up some tiny protractor or something. I just have to run the numbers for a different arm length. This seems like another good method for getting started and then adjusting by ear. Fortunately, my Graham and TriPlanar both have VTA scales. The RB 250 I'm going to mount on a Lenco project doesn't have this but I plan on using an aftermarket Rega VTA adapter.

Simple applied trigonometry. I just can't seem to think like an engineer any more after all these years of writing software.

Thanks again, Neil.

I'm right there with you, Andrew. The starting point has always been something of a mystery to me but this thread provides a very repeatable methodology.

Hi all,

Doug, I do remember that the arm tube seemed a bit low at the pivot but that could have been the angle at which I was viewing it. I've come to learn not to worry so much about arm orientation thanks to threads such as this.

What most impressed me was how you could make a quick adjustment to the TriPlanar and Paul would either nod, winch or shrug. (He did a lot of shrugging with my rock music. :) Paul practically called me a head banger! I think of myself as more of a head banger with finesse, thank yew very much!) Based on my experiences with suspended tables, I swear there were times when my heart would skip a beat watching you quickly, and seemingly without care, beat about the pivot while adjusting VTA. (Not really, Doug is very graceful.)

Andrew, I see where you're going and I'm inclined to agree. IF the armtube angle is based on SRA then, as Neil has shown, changes in the arm angle do directly affect SRA. Perhaps it is picky, but it is important to realize that in the end it is the SRA that makes the difference.

SirSpeedy, if you start using remotes for everything I can promise you'll end up with a bigger spread than mine. Sorry I'm not going to catch up with all of you at VTV. Maybe sometime soon!

Doug,

I knew exactly what the shrugs, nods, etc., meant. And interpretting those indicators is what made it so much fun to watch. I hope we can all get together again before too long. I will have another pre-amp by then and quite possibly another phono stage as well. I'll bring more jazz next time so as not to put Paul off so much! :) I believe I also heard some disparagement towards Nashville so I'll leave the Pickin' music behind as well. ;) Seriously, that was very "eye-opening" to hear how much difference there is between recordings of different musical genres.

SirSpeedy, I guess we'll just have to watch as someone else makes the money. Again! BTW, you once warned me about listening to other's systems and how it can lead to a certain amount of displeasure with your own. Well, it's happened to me. But I do think it is a good thing in the end since what most of us are after is to build our systems as good as we can get them. I also agree with you about different music. I'm fortunate to have a friend who is a very highly trained jazz trombonist. He's taught me a lot about jazz over the last two years so I'm beginning to gain an appreciation for it. Classical is going to take me a while longer but I do have many fairly good recordings both on vinyl and cd.

Chill out, Neil! We're having fun! You're right, of course. Sorry to car-jack your thread. I've bookmarked it for reference when my next table shows up. It's been almost 6 months. I think I getting hives!

SirSpeedy, I tried to send you an email but it doinked. Please contact me off-line.

T thought I'd better come back and make ammends to this thread by posting something useful. :)

If anyone is looking for a source for front surface (aka first surface) mirror I can recommend a couple of internet sources.

www.fsmirrors.com This site is perhaps the better choice of these two with better prices and selection. There is a 4"x5", 3mm (1/8") pre-made for about $21 shipped.

www.anchoroptics.com This site has a commercial grade pre-made mirror that is about 2"x5" and 3mm thick for maybe a dollar or two more.