[Vintage-Audio] Stylus Feedback? Why?

[Duane Fischer, W8DBF]

Hi All,

Several days ago while I was experimenting with different bass, midrange and 
treble settings for my B&W 630 three way monitor speakers, that I sometimes 
blend in with my James B. Lansing Century L-100 ceiling mounted mains, I 
thought that I heard a rumble coming from a source other then my stomach!

Hark! Was that an electronic Harpsacord or just another harmonic caused by a 
Gamma Ray rebounding off that atom smashing thing in the Ann Arbor, MI home 
of the University of Michigan Physics lab where someone got their doctorite 
by discovering that "Wilson-Phillips" could not sing! No! It was coming from 
the eight inch active poly ... some kind of thing woof woof wanna be cone 
three feet to my right.

I got up off the carpeted floor where I had been squatted down doing the IHF 
+/-2 Db adjustment procedure and switched over to the ceiling mounted JBL 
Century L-100's. No rumble, Rumba or other residual reverberations. So just 
what was giving the B&W 630 high frequency bi-wired monitors that rhythmic 
distress?

The Shure diamond stylus was picking up a rumble from the Sony/Marantz 5520 
turntable, amplifying it and causing audio distortion. Frankly, it sounded 
to me as if I had somehow enhanced a turntable drive mechanism rumble 
feedback loop, but only in the one set of speakers. It seemed to me that I 
should have had the rhumba rumble in both sets of speakers.

As Maxwell Smart used to say; "Missed it by that much!" Which explains why 
Secret Agent #99 never became pregnant! (LOL!) It scares me to ponder what 
might have happened if old Max might have hit the target!

I did a little reading in my previously created audio research note file 
circa 1999 and found out that the James B. Lansing Century L-100 speakers 
were low efficiency and that the B&W 630 speakers were high efficiency. A 
concept that I am still not sure I fully comprehend yet today! One of those 
"low" is really high and "high" is actually low cosmic time space 
dimensional shifting event horizon things where one is correct if the 
velocity of light is positively accelerated by the density of a Black Hole 
that is not a hole, but a round sphere that is invisible because of the 
Black On Black optical principal or negatively accelerated if the universe 
is truly infinite and time never ends! No wonder our children can not tell 
what time it is on a watch or wrist watch having moving hands!

So more continuous RMS (What the Hell is Root Mean Square all about anyhow?) 
is going to the B&W 630 speakers and less to the JBL Century L-100's? But if 
the volume control knob is in the same position for both speakers at the 
same moment in time, how can that be? Maybe it has something to do with the 
Metric System! I've always been suspicious about people who called money a 
"pound", when a pound equals sixteen ounces, unless it is a prescious metal 
pound and then is has only twelve ounces! Then they call a "meter" 39.2 
inches and the car windshield a "windscreen"! Someday someone is going to 
make a lot of Yen, Yuro's, Pesos or Ben Franklin's by announcing that the 
real secret hidden in the King James Bible, U.S. Declaration Of 
Independence, ceiling where that famous inventor - painter of nude women - 
gear reduction thing with a big spring that kept time, the day of the week, 
the month of whatever year system was then in use, predicted famines and 
plagues and wars and plagues of Turtles with an image of Susan B. Ugly 
Anthony on their backs ...Discover that it is really the Metric System that 
killed off the Dinosaurs, wiped out the Inca's before the Spanish did and 
tried to cheat the Mayan Indians out of leap year was not the Da Vinci Code, 
but that damn Metric System!

Sorry about that. I just hate it when the deserving person, be it for good 
or evil, fails to get his or her dues because some so called Greek Scholar, 
American archieologist, Soothsayer, cosmic visionary who causes Bald Eagles 
to grow hair on the sixth Thursday of any month with three full Moons etc. 
All because they can not spell on a stone tablet, parchment scroll, chalk 
board, mechanical typewriter or word processing computer program where they 
click the mouse and it fixes all of their flaws!

So tell me, please! Why do I get a sixty cycle hum from the B&W 630 speakers 
when the Shure stylus tracking at 1.25 grams is playing what is hiding in 
those deep dark vinyl grooves and only the sound of silence from the JBL 
Century L-100's? Is it the Simon and Garfunkle effect?




Duane Fischer, W8DBF - WPE8CXO
E-Mail: dfischer at usol.com
Hallicrafters web site: www.w9wze.net
HHRP web site: hhrp.w9wze.net