Letters to the Editor

Does Setting SRA at 92 Degrees Work?

Michael Fremer | Sep 24, 2014

Hi Michael ,

Ever since I set up my Benz Micro Gullwing SLR to 92 degrees VTA w/ the corresponding proper Azimuth set up. As you've lectured in the Hifi show & your DVD. I've been enjoying my system ever since and had no desire to upgrade my system. I listened to my friends system w/c is way more expensive than my system , although I heard some advantages in his set up I had no desire to upgrade because the advantage was not that much. When I listened to my system the next day I still enjoyed it and did not miss the sonics/ sound of my friend's system.

When I first heard Steely Dan' Gaucho Album & Joni Mitchell 's Court & Spark album when my cartridge was set up to 92 degrees VTA I heard details ,nuances & instruments that I've never heard before prior to setting up the proper VTA/ Azimuth.

Thanks for the tip,

Luigi

COMMENTS

I am lucky

Submitted by volvic on Thu, 2014-09-25 06:48

In that my turntable's bearing allows the raising and lowering of the platter which has allowed me by ear to lock into what I think is the correct SRA based on listening. But one can't be all that sure. And I still plan on purchasing an idler and a Rega P9 at some point and even an SME that I keep promising myself so the USB microscope would make sense, but have been putting it off waiting for Soundsmith's Cartright tool which would make all of this set up so much easier. The other issue and I admit I have not yet tried it with the USB microscope, isn't the 92 deg set up somewhat arbitrary? Getting to the proper SRA is still done visually through the screen and doesn't that leave room that one could still be off by a degree or two and not even know it?

92 Degrees

Submitted by Michael Fremer on Thu, 2014-09-25 10:41

Is based on work done in the 1980s by Jon M. Risch and Bruce Maier published in Audio magazine and available for you to download here: http://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra. They visited lacquer cutting facilities and based their ideas upon what they found. They then measured IM distortion and found a strong correlation between lowest distortion and 92 degrees (appx.) which correlated well with cutting styli angles. The angle must be beyond 90 degrees for the vacuum system to suck away the just sliced lacquer, which is highly flammable. So a starting point MUST be greater than 90 degrees. If you place your arm parallel to the record surface and have no means to check SRA, you are "flying blind". I have seen poorly manufactured styli in very expensive cartridges where parallel arm placement yielded 86 degrees or lower! The value of the microscope even if you can't adjust VTA/SRA is that you can see if your cartridge that you've just spend thousands for has been properly manufactured. Yes, the setting at 92 degrees isn't precise--you may find 93 or 91 better because cutter head styli aren't necessarily placed precisely in the chuck. But what is absolutely certain is that the angle MUST be greater than 90 degrees. Those suggesting that you must change SRA for every record are suggesting that we can hear differences of less than 1 degree. I'm not convinced. In any case I got into this whole crazy business to PLAY TUNES. I find that set at 92 degrees, all of my records sound ground. I can live with the possibility that some might sound better were I to fiddle with SRA. Once I'm set up correctly, I'm DONE.

Also...

Submitted by Rudy on Thu, 2014-09-25 10:58

You had also mentioned in your original piece how little the SRA changes for different heights of records (180g or 200g vs., say Dynaflex). And a longer 10" arm has less of an effect than a 9" in terms of degrees of actual change.

I think what really irks me is reading on SO many forums how users start cranking on their VTA settings like a tone control--raise this or lower that if things are too bright or too wooly or...whatever. And that also begs the question: if you're at an ideal SRA of 92° and you don't like the sound, perhaps a change in cartridge is in order.

I'm the same way myself--I want to install that cartridge and play music! Alignment at best is finding that middle ground which works as well as possible with everything you own.

Microscope recommendation

Submitted by gca on Thu, 2014-10-16 09:52

Hi Michael,

Is there a particular brand/model of microscope you'd recommend?

Galen Carol

Microscope Recommendation?

Submitted by Michael Fremer on Sat, 2014-10-18 00:36

I use the Dino-Lite AMT313. See story here: http://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra

Agreed

Submitted by Dorian Workman on Thu, 2014-09-25 07:25

I got a new Ortofon 2M Black for my Traveler and it just didn't sound right with the tonearm parallel. Checked the SRA using Mikey's technique and it was 95-96 degrees! Returned to dealer for a replacement stylus, installed that with arm parallel, checked SRA and got 92.55 (measured by Wally - see images linked below), and now sounds fantastic. This definitely works. I haven't tried to get to exactly 92 as it sounds so good right now...

Original image:
http://i1378.photobucket.com/albums/ah99/Dorian_Workman/A0FBDF81-D81B-41...

Wally response:
http://i1378.photobucket.com/albums/ah99/Dorian_Workman/8C23523B-3E76-48...

Ortofon 2M Black

Submitted by Rudy on Thu, 2014-09-25 10:27

I am lucky in that I can adjust my arm height to get the 92° SRA set properly, yet I still don't think my 2M Black is all that great. I went the USB microscope route, and I also found that not only was the front of the stylus not at a right angle to the vinyl surface (meaning I had to rotate the arm tube slightly to correct it), the square stylus itself was off a degree or two in its mount in the cantilever! Seriously, Ortofon? For a $700+ cartridge, I find this sloppy and unforgivable, and it took me hours of aligning and fussing with USB microscope and oscilloscope to correct its sloppiness.

As you can guess, I'm actively shopping upgrades. ;)

Me Too

Submitted by Dorian Workman on Thu, 2014-09-25 10:37

Yeah I have seen similar issues with mine actually. According to my Fozgometer the azimuth is quite out of whack (L27 / R21). I have a VPI Traveler which doesn't have azimuth adjustment, so I tried shimming the cart with paper shims, as recommended by Harry @ VPI. That got the numbers a lot closer on the Foz, but I actually thought the sound was less focused - so I ditched the shims.

Also when using my Mint LP Best Tractor and 10x magnifier, I see that my cantilver has a kink in it! It kinks to the right about a third of the way up. I just aligned the front of the cantilever 'pre-kink' though, and that seems to have worked.

Overall my sound is great. I do wonder if it would sound even better if I could get the azimuth right without shims, but I'm not prepared to tinker any more as I am really happy with it right now.

My cantilever fortunately is

Submitted by Rudy on Thu, 2014-09-25 10:52

My cantilever fortunately is not kinked, yet it just seems sloppy to have the parameters be so far off. I understand this is manufacturing at the microscopic level but still, this is sloppy for what is a premium product. I'd expect this in a 2M Red...maybe.

My V15VMR (circa 1982) shipped with adhesive-backed plastic tabs for setting the azimuth, and they worked well. Fortunately I was able to fire the USB microscope at the front and tweak that alignment until I got it right. Note that before I started, I had the bottom of the headshell parallel to the record surface...so my arm was setup properly beforehand.

That V15 also shipped with its own alignment jigs. It took me all of five minutes to set it up and start playing records. With the original styli, I never had a problem. (These were the units with the serial number on the front.) When production shifted (to Mexico, I think), I noticed the whole thing seemed a bit sloppy--cantilever not exactly centered in the assembly, that sort of thing.

What Mike is trying to do here is actually STYLUS alignment, not cartridge alignment. That has been my goal (and yours too) all along. I know we can line up cartridge bodies and cantilevers all day long, but without actually seeing where and how that diamond stylus is sitting, we would be taking a huge leap of faith assuming that the stylus is even mounted correctly, or the cantilever is oriented as it should be. My 2M Black is proof of that. The diamond is cockeyed in the mount, the cantilever tube was rotated slightly, and as you've witnessed firsthand, that SRA is all over the map.

Sad, really. I am not all that keen on replacing my 2M Black with another Ortofon after this.

Replacement

Submitted by Dorian Workman on Thu, 2014-09-25 12:02

Let us know what cartridge you decide on as a replacement, and how setup up goes. Thanks.

92 degrees

Submitted by cppsbc on Mon, 2014-09-29 23:18

I have been trying and have not been able to get the type of images you posted. It is almost like being done in a studio. Share with us how you set up, equipment used etc.. to get those fantastic photos.

Colin

It's doable...

Submitted by Michael Fremer on Tue, 2014-09-30 19:28

Put a CD on the platter put the stylus on the CD. Set the magnification to approximately 250x. Scope must be on a stand. The stylus should be as close as possible to the CD edge. Focus on the CD edge and then the stylus should be in focus. Use a good light and fold a piece of white paper right behind the tone arm. You should be able to get similar pictures.

SoundSmith Cartright

Submitted by HiFiMark on Thu, 2014-09-25 07:58

Yes - waiting on the software version for iPhone - it's been "Coming Soon" for what seems like two years now. Anyone know if they are getting any closer?

Called no answer at Soundsmith

Submitted by volvic on Thu, 2014-09-25 09:57

Perhaps if anyone is off to the NYC Hi-Fi show this weekend can ask them and post back, I believe they will have a room.

I am going

Submitted by Dorian Workman on Thu, 2014-09-25 10:39

I will see if I can ask them.

Thanks Dorian!

Submitted by HiFiMark on Thu, 2014-09-25 12:41

For making an attempt at pursuing the question with SoundSmith. I have to believe there are many of us vinyl fans for whom that tool will be of great benefit.

Arm

Submitted by Smokey on Thu, 2014-09-25 11:33

Would it be safe to say that this most of the time would mean the arm at least should not be pointing backwards or even not parallell to the record?

We'll hold you to it Dorian

Submitted by volvic on Thu, 2014-09-25 18:30

We expect an answer on Monday :)

I'm going over Sunday afternoon

Submitted by Dorian Workman on Fri, 2014-09-26 10:27

Hopefully I can get some answers...

And...

Submitted by Dorian Workman on Fri, 2014-09-26 10:28

Looking to forward to Michael's seminar too!

Didn't get to show

Submitted by Dorian Workman on Tue, 2014-09-30 08:07

Sorry but I didn't make it to the show, by wife wasn't too happy about me being out late the night before at the football game.... Did anyone hear anything more?

Nope nothing

Submitted by volvic on Tue, 2014-09-30 08:41

Will try and put a call in today if I find a quiet moment at work and see what if anything they have to say.

Ok got through

Submitted by volvic on Tue, 2014-09-30 08:48

So the answer I got is that it is going to be a while yet.....that he has other projects going and this is not going to come to fruition any time soon. Time to get ready and pay $250.00 for a USB microscope.

Thanks...

Submitted by HiFiMark on Tue, 2014-09-30 09:57

for the effort on this guys. Much appreciated. The scope sounds like a good investment for a group of audio buddies. If I could just find some other than my son and brother - each >800 miles away!

92o & Azimuth 'before and after' Success

Submitted by sbhifi on Fri, 2014-09-26 00:12

I have followed Mikey's USB 'scope technique since he first mentioned it. I also love the Feickert Adjust+ azimuth program. I have now set up dozens of turntables using them. I demonstrate my recorded a 'before' and 'after' files where 'before' is a Pro-Ject RPM5.1 set up with the headshell parallel to the platter and the other with the stylus set to 92o and the azimuth set for optimal phase. The improvement is obvious. And, in all the turntables I have done - interestingly - the correct results NEVER end up parallel to the record and the headshell is NEVER level. Mikey, maybe it's worth posting a couple of your (fantastic) audio files...

result

Submitted by Smokey on Fri, 2014-09-26 07:48

So based on your results, how is the arm normally balanced when you have found 92 degrees?

result

Submitted by sbhifi on Tue, 2014-09-30 05:53

There can be a variety of angles - even within the same brand: Ortofon OM10s have the arm pillar so high that the counterweight touches the lid, 2M usually needs a small lift and, at the other end, models like MC30Supreme and Kontraplunkt a are set so low that the plastic armature cover almost touches the vinyl! There's no doubt that Ortofon know what they're doing - I can only think that they are using the tracking angle to control tone (crispness/smoothness) of certain models. But the diminished surface noise and detail resolution always seems better at 92o to me. The Feickert Adjust plus often recommends rotation of about 1o CW or CCW - even more on older cartridges. I expect to hear better stereo imaging, but I am always surprised by the improvement in high frequency focus when the azimuth is right compared with level. You can even hear the difference on a Pro-Ject Debut Carbon (that has no VTA adjustment) with OM10.

Ortofon 2m black

Submitted by tube dog on Sat, 2014-10-11 16:01

Rudy, I feel your pain. I owned an Ortofon Cadenza Bronze and Black and had issues with both. I now own an Ortofon Windfeld and have had no issues. I guess you have to spend 4K to get a good one. What a fantastic cartridge it is!

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Letters to the Editor

Does Setting SRA at 92 Degrees Work?