Pryso: Doug and I meant the same thing, but notch filter is wrong and does actually the opposite. The correct one needed here is a bandpass that passes only frequencies in a narrow band around 1KHz. Here is a link to some info about bandpass filters: Band-pass filters Band-pass filter on Wikipedia I hope this clarifies things. Rene |
Sorry for the inaccurate term. My electronics skills are easily a match for yours, Pryso. ;-) At least I knew what I meant, and fortunately Rene did too! Doug P.S. Paul and I are among those annoying guys that Tim mentioned in his excellent post. After using the Wally Analog Shop (which works great) to adjust azimuth on several cartridges, we learned we could get just about as close by listening. Our main cartridge goes below the resolution of our multi-meter, which worked out to < 0.1db crosstalk. When azimuth's correct L/R images are so tight they're almost invisible. ;-) Less fiddling time and more music time works for us now, but it was useful to be able to measure and confirm what we were hearing. |
A different question for Doug and others who set azimuth by ear - can this be done by one person while listening off center? My tt is on a side wall, well outside the nearest speaker. I've never tried listening to a test tone for azimuth since it would mean running back and forth between the tt and my listening seat. Also, thanks Rene and Doug for your quick clarification. |
Pryso, You have to be in the sweet spot to fine tune azimuth by ear. That's the only place you can hear your sytem's L/R imaging at its best. Don't use test tones to set azimuth by ear. They wouldn't help. Use music, preferably higher pitched instruments and/or vocals. Our ears are more sensitive to directional cues at high frequencies. Don't use rock, use well recorded acoustic jazz or classical. (Who cares about azimuth for rock anyway? Oops! There I go!!) It's best to rough azimuth in by eye first by making your stylus as close to vertical as possible. No matter what your meter or ears tell you, you don't want your stylus significantly off vertical - for the sake of your records and your stylus. If you have to angle it more than 1-2 degrees something's wrong (probably with the cartridge, few are perfect). Before attempting to fine tune azimuth any more closely, make sure all of the following have been done: 1. your cartridge is well broken in 2. VTF is optimal (set by ear, not just by what some scale reads; if you can't set VTF by ear you certainly won't be able to do so with azimuth) 3. Antiskating is optimal (set by ear, not by what some dial reads; ditto for needing to be able to do this by ear before attempting azimuth) 4. the system and cartridge are warmed up, play 2-3 sides before you begin. I can't describe what to listen for any better than Jtimothya did: Listen to a female vocalist who sings center stage. Adjust azimuth to get her mouth/voice as small/narrow as you can. Incorrect azimuth tends to splay sounds horizontally, making instruments and voices larger (spread wider) than they will be when azimuth is correct.When you think about what crosstalk does to a stereo image, you realize that's a perfect description. |
Doug, good stuff, very helpful. I always assumed judging azimuth correction would require listening from the sweet spot but never tried it. My cartridge set ups have been limited to a close visual check for front vertical alignment of the stylus. This whole series of posts has been informative so thanks too to Jsman for starting it off. |
