curved or straight tonearm?
On Mon, 26 Sep 2011 07:04:52 -0700, isw wrote
(in article ):
In article ,
Audio Empire wrote:
On Sun, 25 Sep 2011 13:46:02 -0700, Rich Teer wrote
(in article ):
On Sun, 25 Sep 2011, Edward wrote:
i'm looking at seriously upgrading the turntable situation for my "at
home" stereo set up. serious in the sense of quality and that i would
like this to be the last turntable i buy. maybe...
so my question is this: do i go with a curved or straight tonearm??
remember, this is for my home set up and not for taking out of the
house and DJ'ing with.
I don't think the shape of the arm is important per se, provided the
offset angle ends up being correct. That said, all the better arms
I can think of off the top of my head are straight, so I guess there's
your answer!
What TT are you planning to use, and what's your budget? (What cartridge
too?)
The shape is not important, PER SE. What is important is the position of
the
stylus on the record with relation to the arm pivot point. Curved arms
allow
for a more ideal tracking angle with a shorter distance from stylus tip to
pivot point, I.E., a physically shorter arm tube.
Whether the arm is straight or curved won't affect the tracking angle,
provided you're willing to set the cartridge at an angle to the
(straight) arm. Another thing that is important is the mass of the arm
(including the pickup, of course) -- it should be as low as possible for
best tracking, especially of warped or eccentric records (of which there
are more than you think). In this, a straight arm with an offset
cartridge will win.
Isaac
"(The mass of the arm) should be as low as possible for
best tracking"
Depends on the cartridge. Ideally, the total mass of the arm/cartridge,
combined with the stylus compliance should allow for a system resonance of
between 8-12 Hz. That would be a frequency lower than the lowest note on the
record (about 20 Hz for pedal notes) but above the frequency where foot-falls
and warped records would excite the system (around 6 Hz). Some cartridges
need low-mass arms to attain this ideal resonant frequency, and some need a
low-mass arm.
Generally speaking, Arms with high effective mass, when used in combination
with high-compliance cartridges will yield a resonant frequency which falls
below the ideal range making it susceptible to being being dislodged from the
groove by heavy footfalls and making the system overly sensitive to warp-wow.
On the other hand cartridges with low-compliance, used in conjunction with a
low-mass arm will move the system resonance up into the audible range,
resulting in overblown and muddy bass. Obviously both extremes should be
avoided for bast results.
While this is obviously simple physics, it is also one of the least
understood and one of the most ignored phases of most people's record playing
setups. People buy an arm (or a turntable/arm combo) and then pick a
cartridge based on reviews or upon having heard a certain model at a
friend's house or a hi-fi show, and pair the two without even a thought as to
compatibility. The industry hasn't helped much either. There are rarely any
guidelines given for pairing either arm or cartridge, and when there are,
they are vague and don't make a lot of sense to the average audiophile. What
the industry should have done, years ago, is to come up with some simple
number matching system for both arms and cartridges. Ideally, thei system
could have worked like this:
Cartridges could be classed using the numbering system 1 through 10 with 1
being an extremely high compliance cartridge and 10 being an extremely low
compliance cartridge. Then arms would be rated using the same scale 1 through
10, only with 1 being a low-mass arm and 10 being a high-mass arm. To gauge
compatibility all the buyer need do is match numbers. A cartridge with a
rating of 3 would match with an arm rated at three (with more or less
acceptable performance being obtained by using an arm rated from 2 to 4).
Some system like this would be very helpful, but nobody has ever done it.
I usually recommend that people buy complete turntable packages - preferably
those put together by the manufacturer, such as the Clearaudio Performance SE
Package (which comes equipped with suitable Benz MC cartridges) or the
various Rega or Music Hall turntable/cartridge combos. Generally speaking,
you'll get better performance with an inexpensive combo package where the arm
and cartridge are a well thought-out, synergistic system, than you will with
a more expensive setup where the arm/cartridge interface is left to chance.
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