Adjusting SRA using macro lens vs microscope

Doug,

Thank you once again for being an informed voice of reason. This thread is a nice counterpoint to a thread in another forum entitled "Why Some Audiophiles Fear Measurements". It's not that some measurements aren't useful (they are), but it is human nature to attach a false sense of security to a measurement. An interesting take on this subject is "The Tyranny of Numbers" by David Boyle.

As Doug points out, does anyone think fixing SRA at 92.1 degrees really be any different than 92.0 degrees if you own a large record collection?

Doug, as you said Sat, you know that you can use the body of a Universe to start because you have looked at the stylus on a few samples and have concluded that the stylus does end up close to a starting SRA/VTA when you level the body.

I do agree with Doug that going to the effort to measure stylus angle with a microscope and some software is un-necessary. I also think a good 10x or 20x jeweler's loupe is sufficient along with good lighting.

I don't find Nsgarch's method that useful myself. This method assumes that the stylus is symmetrical, but almost none really are. There is usually an edge or facet that is the reference line and this would necessarily result in casting a non-symmetric image on the mirror. This method would never work on a stylus like the Replicant, but I would submit that few visual methods, if any, will work with the type of profile the the Replicant has.

We ended up leveling the body of the A90 because the stylus is shaped the way it is, and we had no other choice. I still want to know what reference point to use on that Replicant stylus to find the 90 degree angle referenced in the Ortophon directions and by Fremer. There is supposed to be some tiny, trailing edge facet that is the actual surface to consider, and maybe that does require a microscope to see. I would still not give up the step of actually looking at the stylus for most cartridges. I don't think I will count on a cart builder to set that angle with the body any more than I would expect the AZ to be perfect. I simply put the A90 in a category (almost by itself :-)) where usual methods may not apply.

All of my comments assume that the tonearm in use has the capability to make easy VTA adjustments.

So gentlemen, what did you think of the A90?

Richard, I didn't hear it committing any sins. The A90 is very respectable from my short time listening to it.

Agree with Dan. The system had few commonalities with ours, so whatever anomalies Paul and I noticed might have been attributable to many things.

FWIW, the A90 is one of a very few cartridges I've used that has as narrow a range for VTF, SRA and azimuth as a UNIverse. It is very easy to set up sub-optimally. As with a UNIverse, that results in sub-optimal performance and could cause one to mis-judge the A90's capabilities.

We found it easy to hear when SRA or VTF were "off" and easy to decide which way to go. That suggests a nicely linear design. A cartridge that's unclear about which direction is right may end up sonically flawed even when optimized. The A90 was admirably clear.

Apologies to Glai for the thread-jacking.