4
By the early 1980’s it was generally acknowledged that lower output moving coil
cartridges were capable of retrieving signifi cantly more fi ne detail from record
grooves than higher output moving magnet cartridges. In many instances this was
simply a case of having lower moving mass to accelerate in the electrical generator
mechanism of the phono-cartridge. Moving coils with 3 or 4 turns of the fi nest wire
attached to the lightest and stiffest cantilevers were capable of accurately tracking
complex musical passages that a few years prior would have seemed impossible tasks
to engineer and listener alike.
The really astute cartridge makers had clearly taken a page from the automotive
and motorcycle racing cognoscenti, whose engineers were doing everything in their
power to lower “un-sprung mass” in an effort to get tires to say in intimate contact
with the roughest terrain at the highest possible speeds. In both worlds the ability to
accurately track the impossible landscape is the ultimate goal….. minimal moving
mass associated with a compliant suspension is a big part of the answer.
Unfortunately the active electronics that were capable of extracting signal at those
low levels, frequently then buried much of that signal in their own noise fl oor. Step-
up transformers generally addressed the noise issues, but frequently lost the very fi ne
detail somewhere in the transformers iron core. For the time, the promise of the best
moving coil cartridges went un-realized
The XP-27’s high gain and exceptionally low noise fi gure allow for ample output and
detail from cartridges providing as little as 40 uV (micro-volts) of signal at the phono
input. The adjustable gain options of the XP-27 make this unit immune from overload
with any high output cartridge of which we are familiar.
The XP-27 is as much a pleasure to use as it is to listen through, thank you for trusting
your ears and your vinyl collection with us. Before you sit back and listen, take time
to read and understand cartridge loading. When you fi nd the desired setting,
please record that setting so that you can come back to it in the future. For your
convenience we left space at the end of this manual for just these sorts of details.
Thank you for purchasing this “product”. It is my sincere hope that you will enjoy its
sound as much as we do.
Pass Labs
TECHNICAL DETAILS:
As previously indicated the XP-27 is a twin chassis design. One chassis holds the fully
fi ltered and regulated power supplies and the second chassis houses the analog
gain circuits, input switching, loading and all those details and features normally
associated with a reference RIAA phono stage.
The two chassis are interconnected with 9 conductor cable. This cable only carries
power, never analog signal. Consumers frequently ask us if they may substitute
a cable of their choice for the one Pass Laboratories supplies. The answer is yes,
provided that cable carries all the necessary legal approvals.