McGary Audio

Monday, February 27, 2012

Audiophile Review!
Pass Labs XP15 Balanced Output
Stereo Phono Preamplifier




Brevis:
Price: $3,800
Likes: audio quality, adjustability
Dislikes: small switches on rear panel
More info: Pass XP15 Preamp

by John Gatski

We have gone through CD, DVD-A, SACD and digital FLAC downloads, and yet the analog LP record will not die. Who would have predicted that in 2012, good old vinyl technology would not only survive, but flourish among the various evolutionary stages of digital playback. Hundreds of LP products are now available through online and storefront dealers, including state-of-the-art bargain and high-end turntables, cartridges, preamplifiers and all sorts of accessories. And, of course, there is plenty of new music on record: Pop, Classical, Jazz, and Hip-Hop, as well as plenty of reissues and remasters.
With the esteem that LPs still hold, Nelson Pass and company know a thing or two about analog phono preamps, and recently released their new products: The flagship XP25 and the XP15, reviewed here.

Features

Priced at $3,800, the USA-designed and manufactured dual-mono stereo XP15 was designed by Pass Labs engineer Wayne Colburn. The MOSFET-output preamplifier is part of Pass’ X Phono series, this one being the base model with internal power supply. The $10,600 XP25 contains an outboard power supply and better spec’d internal components.

According to Pass Labs, the XP15 can accommodate any moving magnet, moving coil or moving iron cartridge ever made. The lowest output moving coil cartridge can work through the XP15 without a head amp. The Pass pre can output gain in excess of .5V with a cartridge of just 80 micro-volts. The XP15 is quiet, too, with a rated -90 dB noise floor in the MM mode when outputting a signal via the balanced XLRs. The RIAA phono curve’s accuracy is as good as it gets — within 1/10th of a dB over 10 octaves.



This is an audiophile preamp for the guy who wants an honest impression of his LP rig. Throw in the cartridge-matching controls, and you’ve got yourself a great entry-level phono preamp. Even those with more expensive audio component tastes will be impressed.


The XP15 is housed in Pass’ high-class, metal chassis with its minimalist anodized front panel. Inside, Wayne Colburn and crew designed the unit with high-spec parts in its JFET input/MOSFET output layout. The custom-made power supply and related components give the XP15 its excellent specs and are key to its detailed accuracy and high signal-to-noise numbers.
The back panel is where the action is — with premium phono RCA input jacks for each channel, an array of adjustment DIP switches and unbalanced and balanced XLR outputs. Each channel contains a MM RCA input, and a MC RCA input, as well as unbalanced and balanced XLR outputs.
There are two banks of DIP switches for each channel: one includes the MM/MC gain selection and cartridge loading adjustments. Cartridge loading can be adjusted from 2 ohms to 47 k-ohms. The other DIP switch enables user adjustment of parallel capacitance — from 100 pF to 750 pF. The manual lists capacitance and loading values, based on the various combinations of DIP switch adjustments.
The setup
Although I have been heavy into high-res PCM and DSD components since 1995, I have always kept a turntable in good working order. I regularly purchase audiophile vinyl and have a number of good condition, classic direct-to-disc and half-speed mastered LPs from Mobile Fidelity, Nautilus, Telarc, etc.
My turntables are well-played classics, not too expensive, but still pretty viable: an early 1980s Luxman PD Series 264 and a late 1997 Rotel RP-950. The Luxman contains the last version of the Shure V15 (I bought spare styli). And my trusty Rotel was set up with my favorite MM cartridge, the ultra-accurate, Audio-Technica ML150.
For this review, I also borrowed a Marantz TT-15, a nice $2,500 straight-arm turntable that is made for the big “M” by ClearAudio, with its factory-installed, moving iron cartridge and big acrylic platter. The rest of my system included a Rogue Audio Model 99 magnum tube preamp with tube phono stage, AVA Fet/Valve preamp with tube phono stage, Legacy Coda line preamp, Pass Labs X350.5 amplifier and Legacy Focus 20/20 speakers. Alpha-Core solid-silver line cables and speaker cables completed the setup. All components were connected to AC via the Essential Sound Products Reference series power cables and power strip.



I quickly locked my ears onto the XP15‘s tight bass and detailed midrange and treble. Despite the nearly 40-year old LP, the Isao Suzuki LP sounded amazing. Mr. Suzuki’s cello is rich and dynamic — without excessive bass bloom that I have heard on more expensive, standalone tube phono pres.



I also enlisted the help of Bill Thalmann of Music Technology, in Springfield, Va. to add some diversity to the XP15’s test run. Bill kindly allowed a listening session at his place with an 1980s Oracle Delphi 5 belt-drive table equipped with Oracle SME IV tone arm and a Soundsmith AIDA moving iron cartridge. His playback system was no slouch either: a Conrad Johnson Premiere 15 phono pre, a Conrad-Johnson Premiere 4 MOTIF line-preamp (modified by Bill), and heavily modified C-J mono tube amps. Speakers were an upgraded set of Apogee Slant 6 speakers.
For all the setups, we set the cartridge loading and capacitance based on the manufacturer specs. The small rear-panel DIP switches allow the manufacturer to give it adjustment flexibility, but you need to make sure you set it right the first time before you put it back in the rack. Having to re-adjust requires pulling the preamp from the rack. and moving those rear-panel-mounted, tiny switches with a tiny screw driver. In our darkened listening rooms, a flashlight also came in handy to help strained eyes to spot those tiny DIPs.
The audition
My initial listening tests were done with the capable Rotel turntable/AT-150ML combo and several jazz LPs (an original Isao Suzuki Trio/QuartetBlow Up, Three Blind (Mice Records); Cadillac And Mack The Detroit Four, (East Wind Records); and Stephane GrapelliUptown Dance (Concord Records).
I quickly locked my ears onto the XP15‘s tight bass and detailed midrange and treble. Despite the nearly 40-year old LP, the Isao Suzuki LP sounded amazing. Mr. Suzuki’s cello is rich and dynamic — without excessive bass bloom that I have heard on more expensive, standalone tube phono pres. The XP15‘s tendency toward bass accuracy and impressive transient response complemented the A-T cartridge perfectly.



It was like the detail of digital, but with that direct, open analog sense we all love from LPs. The Marantz TT-15 and its moving iron cartridge was not quite as lively as the 150 ML, but its upper-end performance was certainly more noticeable using the XP15 than my straight tube pres. For instance, the drum cymbals on the 45 RPM audiophile edition of Wes MontgomeryFull House sounded better than the CD; it sounded more like an SACD — with impressive width and depth in the stereo image. The other thing I noticed with low-noise MM cartridges: the XP15 maintains that quiet quotient. Other than the typical clicks and pops, the line noise heard through the speaker was nil.
The preamp is just not for jazz and classical LP lovers. My Muddy Waters — Folksinger (MFSL) remaster was as dynamic as I ever heard it — with Mr. Waters’ expressive vocals and acoustic guitar licks coming through loud and clear. The MFSL reissue of John HiattBring The Family is a great-sounding pop record with a nice airy top end, present acoustic guitar, mild overdriven electric guitar and a punchy drum tone. The Pass preamp certainly made it that much more enjoyable. Like most Pass audio components, the XP15 managed to eke out a little extra detail. For example, the piano on John Hiatt's “Have A Little Faith in Me” really nails that woody grand piano tone, and it takes a good preamp and accurate cartridge to hear that extra dimension.



The MFSL reissue of John Hiatt — Bring The Family is a great sounding pop record with a nice airy top, present acoustic guitar, mild overdriven electric guitar and a punchy drum tone. The Pass certainly made it that much more enjoyable.


With the XP15 in line, Bill Thalmann’s record playback system revealed, generally, the same openness and accuracy that my system conveyed — though presented with a slightly warmer tube character than my all-solid state component complement with the Pass XP15. Still, I thought his Oracle turntable and cartridge sounded tighter and more detailed through the Pass phono preamp than his C-J. Through the Pass, The DoorsLA Woman audiophile release LP was simply amazing on his system. The keyboards and drums sounded like we were hearing the reference master tape.
As I assessed the overall grade of the Pass XP15, my notes never had any negatives with regard to its sonic attributes. Other than the hard-to-reach rear-panel MM/MC selection/load and capacitance adjustments, I had no complaints with the Pass XP15. If you need easy control access, the XP-25 has front-panel controls for cartridge matching, but with a much larger price tag. From its performance and build quality to its tasteful, understated visual persona, I do not think it is that expensive at $3,800 — at least in audiophile terms. I quickly got used to the Pass XP15 as my reference phono preamp. In fact, it made me appreciate the vitality of LPs all the more as I played some of my favorite records.
The verdict
Although phono components can create a euphonic quality that offers a desired, but often colored sound, the Pass XP15, properly matched with an accurate as possible cartridge, is a refreshingly tight, fast, accurate phono preamp that brings out the detail and stereo image. This is an audiophile preamp for the guy who wants an honest impression of his LP rig. Throw in the cartridge-matching controls, and you’ve got yourself a great entry-level phono preamp. Even those with more expensive audio component tastes will be impressed and keep the Pass around a while (or at least ‘til they upgrade to big brother XP25). I am quite happy to give the XP15 an Everything Audio Network Stellar Sound Award.

©All original articles on this site are the intellectual property of the Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited.

No comments: