Pass Labs XA30.8 class A stereo amplifier Review

Pass Labs XA30.8 class A stereo amplifier

In my review of the First Watt SIT-1 mono-blocks, I said, “If you’ve been an audiophile as long as I have, Nelson Pass is probably nearly a legend to you. I remember in my early twenties drooling over the Threshold amps. In the mid 80s he designed the real bargain amp of the day, the Adcom GFA-555 amplifier. For the past few years I’ve noticed as I attended audio shows, that I consistently enjoyed the rooms that used Pass Labs amplification.” Still, this the first review of a Pass Labs product for me. I have used a couple of Pass Labs phono stages, but never long enough for a review.

The reason for this review is kind of interesting. I knew I had a pair of Wayne Picquet’s restored Quad 57 coming in for a while, so I was trying to figure out what amp I wanted to use with them. Years ago when I owned the 57 my two favorite amps to use with them were the Bedini 25/25 and even better, the original 25-watt Electrocompaniet. Both of these were Class A transistor amps. I was not able to find anyone who had either of these two to spare, so I begin to look for a current production amp that was a low wattage Class A amp. There were less choices available than I had expected, but the just released Pass Labs XA30.8 looked perfect on paper. When you combined this with the fact that one of the constants at audio shows is how good rooms with Pass Labs amps sound, I requested an XA30.8 for review and the people at Pass Labs were nice enough to send me one.

In fact, they were so quick getting it to me that I had the XA30.8 in before the Quad 57 arrived. Even though 30 watts is a bit of overkill for my 104 dB efficient Teresonic Ingenium XR Silver, I decided to start the review using it with them. I also used the XA30.8 with the new 47 Labs Alnico Lens II bookshelf speakers and the Audio Note K/SPe.

Pass Labs’ new line of amps, the “XA.8” are designed to bring us amps that are even closer to the company’s “Xs” amps. Pass Labs says the “XA.8” amps were issued to celebrate the company’s 23rd Anniversary. The output stages of the .8 amplifiers bias more deeply into the Class-A operating region. The XA30.8 tops out at 40 volts and 20 amperes and like all the other XA models, produces 26dB of voltage gain. Their larger push-pull Class-A operating area is said to deliver lower distortion and additional loudspeaker control at ordinary listening levels. With the XA.8 they also uniquely molded each model’s front ends to the specifics of its output stage so that the nine amplifiers’ front ends vary in size, voltage, bias current, dissipation, and single-ended vs. push-pull bias distribution. They also used larger power supplies, more storage capacitance, more precise reference voltages, and new, larger heat sinks. The amp is really heavy and the heat sinks are fairly sharp, just a word of warning.

Description

The look of the Pass Labs XA30.8 has changed somewhat from the XA30.5. The faceplate in particular has changed. For last few years Pass Lab amplifiers have looked a lot like the X.5 series which has a two-part face plate. The front section had a circular opening framing the large round bias meter which was mounted on a second sub panel. Now, only the X.5 line retains this two-piece sculptured look. I’ll be honest, I really thought they looked classy. While the new XA.8 series looks really nice, I still liked the older look. The XA.8 series has a simple .75-inch front panel that is a single slab of aluminum with beveled edges and the large round bias meter centered on the front face. The meter shows the current draw of the amp. When the XA30.8 amp is operating in Class A the needle stays at 12 o’clock or very close to it. When the amp goes out of Class A the pointer may move to the right. It never did this with any of the speakers I used, regardless of how loud I played them, and I like loud music.

The XA30.8 is 19 inches wide and 21.25 inches deep, which means it won’t fit on a lot of people’s racks; I barely got it on mine because the rack is double wide. One other point, be sure it has lots of room to breathe; like all Class A amps it runs hot, thankfully not as hot as the First Watt SIT-1, probably due to its massive heat sinks. They look like something you would see on an amplifier that puts out several hundred watts. One warning: the heat sinks are extremely sharp as I learned the hard way. (Wait a minute, those cuts on your legs I saw the other day, I thought it was from the door of your sports car… -Pub.)

The only button on the Pass Labs XA30.8’s front panel is for power but around back you’ll find both unbalanced RCA inputs and balanced XLR inputs. It comes with U shaped jumpers in the XLR sockets. If you chose the RCA inputs then the XLR input sockets must have the U shaped jumpers connecting the input pin 3 to pin 1, ground. You will also find four massive speaker cable binding posts that unlike the X.5 amps, they do accept banana plugs, the main AC power switch, a 5 Ampere fuse socket and below the fuse is an IEC power cord receptacle. The last thing on the back is the one I was most thankful for, two big, heavy weight handles. Come to think about it why doesn’t everyone put them on the back instead of the front.

Setup

My reference system consist of the AMG Viella V12 turntable, Soundsmith SG-220 Strain-Gauge cartridge, Emia Remote Autoformer, Teresonic Ingenium XR speakers with Lowther DX4 silver drivers, High Fidelity Cables CT-1 and CT-1 Ultimate Reference interconnects, speaker cables, and power cables plugged into a HB Cable Design PowerSlave Marble. The amp the Pass Labs XA30.8 replaced was my beloved Wavac EC-300B with NOS Western Electric 300Bs and NOS Western Electric front end tubes. When I say beloved, I like this amp so much that I built my system around it.

With a shipping weight of 106 pounds the hardest thing about setting the Pass Labs XA30.8 up was unboxing it and getting onto my Box Furniture Company D3S Audio Rack. With it in the system I plugged an iPod into the Emia Remote Autoformer and let it play for the Labor Day weekend. I figured I got about 100 hours on it while I watched baseball, college football and enjoyed a day in the Napa Valley. It continued to slightly improve for the next couple of hundred hours.

Breaking-In and Warm-Up

The Pass Labs XA30.8 amp requires a lot of power; it draws 375 watts from your AC. So, it should be no surprise that it takes a while to break-in. This amp was brand new and when it was first turned on it’s got the new electronics smell that I have noticed before with some new equipment. By the way when it goes away the amp is more than half way broken-in. Now don’t get me wrong the XA30.8 sounds great right out of the box but just slightly veiled. These veils will be lifted with time.

Warm-up is an issue I seldom talk about. My Wavac EC300B sounds great in about 15 minutes and I never turn off my Electrocompaniet in the other system. Because of the heat and draw of the XA30.8 you will probably want to make use of that standby switch. The amp takes nearly an hour to come to life when coming out of standby but if you turn it completely off with the switch on the back, then it’s a different story. It takes at least half a day of playing to come around.