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XP-15 Owner’s Manual
Pass Laboratories has long been respected for building some of the
finest phono-stages in the audio industry. Since 1999 the venerable
Pass Laboratories X-ono has been respected by both consumer and
professional user as one of the premiere reference phonostage pre-
amplifers.
As associated equipment in the audio chain has improved we at
Pass Labs found ourselves longing for an improved phono-stage
with even lower noise, greater resolution and sonic ease than we
had enjoyed with the Pass Labs X-ono. The culmination of that
investigation resulted in the XP-15, Wayne Colburn’s latest phono-
stage and successor to the X-ono.
Thank you for purchasing the XP-15, we trust that you will find it
easy to set up and a joy to use.
The XP-15 has a very accurate RIAA equalization curve. This curve
is accurate to better than 1/10 dB over 10 octaves. The accuracy
of this curve does not vary with an adjustment change of gain or
cartridge loading.
The XP-15 features gain adjustable from between 46dB and 76dB; a
range sufficient to allow successful operation of not only high output
moving magnet cartridges, but also the lowest output moving coil
cartridges without the use of an auxiliary step-up transformer.
By the early 1980’s audiophiles recognized that in general lower
output moving coil cartridges were capable of retrieving more fine
detail from record grooves than higher output cartridges, in many
instances this was simply a case of having lower moving mass to
excite in the electrical generator of the cartridge. Moving coils with
less than a half dozen turns of the finest wire possible attached
to the lightest and stiffest cantilevers were capable of accurately
tracking musical passages that a few years before would have seemed
impossible.
The cartridge makers had clearly taken a page from the automotive
and motorcycle racing engineers who were doing everything in their
power to lower “un-sprung mass” in an effort to get tires to stay in
intimate contact with rough terrain at high speeds. In both regards
the ability to accurately track the impossible is the ultimate goal….
less moving mass attached to the suspension is a big part of the
answer.
Unfortunately the active electronics that could extract signal at those
low levels typically added noise. Step-up transformers generally
Introduction
