How to set SRA after determining true vertical?


Here is a picture of a stylus with zero rake angle:

http://members.cox.net/nsgarch/SRA@%200.0%20deg.jpg

Since all modern styli are symmetrical in the x and y plane about the verical z axis, the tapered stylus and its reflection will make a perfect "X" when vertical (z axis perpendicular to the groove) and viewed from the side.

This condition is established by raising or lowering the tonearm pivot post. Once you find this point, and assuming you have a typical 9" tonearm (about 230 mm from pivot to stylus) then each 4 mm you raise the post from the zero
SRA point will apply one degrewe of SRA to the stylus.

A test setup is shown in these two pics:

http://members.cox.net/nsgarch/SRA%20setup1.jpg
http://members.cox.net/nsgarch/SRA%20setup2.jpg

Equipment includes:

a mini Mag-Lite flashlite,
a first surface mirror from old SLR cameras -- easy to find at photo repair shop)
a 50X pocket microscope
bean bags

Don't forget to first remove antiskate and set VTF.

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128x128nsgarch
Nsgarsh,as usual,is correct regarding aural adjustments,and listening for bass.However I have found that though "the bass thing" is high on everyone's list,what really locks in the "now we're in the ballpark" area is extreme high frequency reproduction,played back at a good respectable level(NOT cracking plaster,though),and concentrating on tonal purity at these frequencies.Also,something like a triangle,being struck repeatedly,or better yet,some handbell music(A handbell choir will have a huge variety of fine inner detail,and hopefully superb naturally resonant inner textures at high frequencies).

What should be keyed on is trying to voice to the PUREST textures.This should come across as almost sweet,without the colorations normally associated with that word.

It's all too easy to "think" we have good bass,and this can leave a gap between fine sound and "spot on",which is the Grail, all of us seek.

A few LP's to consider(not that there aren't loads of others,but these are superb,though possibly hard to find)-----Ancient Airs and Dances of Hungary(Harmonia Mundi).---Music of Ancient Greece(Harmonia Mundi)--The Pealing Bells Of the Westminster Handbell Choir,this one is UNBELIEVEABLE,also can be found for about a buck(on the Omni-Sound label)---the soundtrack to the Bdwy play RASHOMON,another incredible disc,"worth it's weight in styli",and has some amazing and different/unique high freq instrumentation,with gorgeous different music(the Carlton label,which was pressed by U.S.Mercury)---Seventy Six Explosive Percussion Instruments,a direct disc on the Sonic Arts label.This is not what you may think,and has gorgeous subtle instrumental textures,as well as bang.------Russo's "Street Music",coupled with An Amer in Paris,on Deutch Grammaphone,killer sound with a harmonica that should seem to be played by Casper the Ghost,floating between your speakers.----EMI-Rachmaninoff's Vespers(pressed in USSR,but fabs),this has a TON of massed voices at almost constant crescendo level,and will immediately tell you if the arm/cart is dialed in correctly,or it will sound like steel wool.A killer disc(so good,you almost need nothing else).---Lastly---------The EMI boxed set of Penderecki orchestral music(I think three discs)containing the JAW DROPPING Harpsichord cto,which will knock anyone out of the "listening chair"!!----Oh,I forgot to mention "The Music of Franz Waxman",on the RCA label(prefferably English,but I have the U.S. pressing)Here is some great stuff,but the Piece d'la Resistance is "Bride of Frankenstein,Creation of the Female Monster" ,INCREDIBLE,FANTASTIC,STAGGERING,and actually lovely harmonic music.My pal Sid(the LP KING,for new discoveries)surprised me with this,some time ago,and just before Halloween.A real treasure!!High frequencies,and "LOWS" you NEVER KNEW YOU HAD.Guaranteed!!!

Let's face it--Analyzing equipment is great fun,but we do it for the MUSICAL PLEASURE,and great "FINDS",that seem to be available only on LP!!

Hope I didn't waste this post,with these,but they have proved invaluable(along with countless others)for helping to dial in my set-up,as well as some of my friends.The music,and sound are all "to die for",as well!

Best!!
Dear Neil: I'm with you about: " Listen first to bass. ".

What happen in this frequency range has a high influence in the whole percieved sound , if it is bloated then we have a " darkness " that preclude natural/transparent sound but if it is muddy then the music foundation " is not there " and you know it. When the bass frequency range is spot on : the whole thing are spot on, at least this is my experience.

Sirspeedy: " It's all too easy to "think" we have good bass..."
Well, yes it is too easy: for the people that are not too experienced or to the people that are not in " touch " with the live music.
Your high frequency approach is a valid one too but I think is a little more " volatil " than the Neil one ( bass range ).

It is curious, I have a record that is one of my reference ( the top one ) LP for to know how near/far I'm from the " spot on " and in this record I'm not looking for any of both frequency extremes: I'm looking in the mid range. This record is one from Janis Ian ( Breaking Silence ): side 2 track 1: here it is ( at the middle ) a battery sound that when the drummer hit it you know when its right and when this recorded " battery moment " is " spot on " every thing is right, till now never fail.

Regards and enjoy the music.
Raul.
Raul,you are aware that the cutter angle always determines where the vta will be best.All lp's vary to some degree,but I don't like to adjust to each record.I know this is not new to you.So no need to respond.Also,I use a number of lp's to make my "averaging".Also if one sets to what we hear as high freq "PURITY",over a wide range of tough to track lp's,you will be in the "perfect" zone!!BTW--If you like the wonderful "Breaking Wind",oops,just kidding,I meant "Breaking Silence",You will LOVE the Ricky Lee Jones LP,called "POP,POP"!!Out of print,but worth seeking out.

Best!