A TUNE-UP FOR THE DUAL TURNTABLE - ThaiHDbox

phono By Tom Yeago
The Wretched Excess
AR Turntable Renovation, Pt. 1
Bringing a venerable classic into high-end contention.
PHOTO 1: An overall perspective shot of the completed table and Defarge arm. The
woodwork, leather surfaced motorboard, and scale (approximately 18� � 18�) are evident.
PHOTO 2: A perspective shot without the outer platter. The twin motor layout and
other details are visible. That’s a record weight on the left rear.
28 audioXpress 12/10 www.audioXpress.com
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like turntables. I mean, what’s not
to like? They grant you access to
scads of software (LPs) which are
elusive if not impossible to find on
CD (although I’ve no real complaints
about the CD format). They’re technologically
accessible (i.e., you can actually
get under the hood and work on them),
and their mechanical simplicity is appealing
to the point of being engaging—charming,
even.
I speak here of the iconic AR (Acoustic
Reseach) XA manual turntable, a
classic not only worth having, but worth
screwing around with. That is what this
project is all about: screwing around with
the AR turntable until it’s transmogrified
into something beyond recognition.
Hence the title, “Wretched Excess.”
This began innocently, as most silly
things do, and grew like topsy (Photo 1).
I wound up with a table with a moderately
heavier platter, but lots of damping;
a table with a low contact, low clearance
bearing, with a belt drive system that
doesn’t impose bias (lateral) force on
the bearing. And a suspension system
tuned a full half-octave lower than the
stock XA (which is simple, really; same
springs, twice as heavy). I also designed
it so that the sub-chassis bounces in unison—or
reasonably close—which wasn’t
difficult. You just need to ensure that
each spring sees the same load.
This won’t be a set of instructions so
you can replicate this beast. I’ll provide
the photos and occasional figure, and
describe what it is I’ve cobbled together,
and why. If you want to build your own
and have a reasonable set of tools and
mechanical chops, you’re all set. You’ll
probably want to make changes here and
there, according to your own lights or
cherished crackpot theories about tables,
to which I say, “Have at it!”