Setting Up and Using the A-S801
The full-width amplifier slid easily onto a shelf of my equipment rack with plenty of clearance for ventilation. It ran barely warm to the touch when playing. I used the power cord furnished with the amplifier, reasoning that at this price level users would probably not spring for an aftermarket cord. Since the amplifier had facilities for a 2.1 speaker system, that’s what I used: KEF LS50 satellite speakers with a JL Audio Fathom f110 subwoofer. To evaluate the A-S801’s bass performance, it was necessary to let the amplifier run full-range, so I turned the subwoofer off for that. Blue Marble Audio speaker cable, with banana plugs on the amplifier end, made it easy to connect to the A-S801’s speaker terminals. An HP Envy laptop computer running 64-bit Windows 7 and Roon server software comprised a computer-based server. It was connected to A-S801’s USB input using Audience Au24 SE USB cables. I remotely controlled Roon from both the iPad version of Roon Remote and from a second copy of Roon installed on a Toshiba laptop computer. It was cool to be able to use the Toshiba laptop to write this review and then switch over to use it as a remote for Roon. I also tried a dedicated server, the Linux-based Aurender N100H, connected to the USB input with a Wireworld Platinum Starlight 6 cable. The servers were connected to my home network, where I store my collection of music files on a QNAP TS-251 network attached storage drive.
I downloaded a copy of Yamaha’s Steinberg USB Windows driver Version 1.9.5 for the A-S801 and installed it so the computer would recognize the A-S801’s DAC, then changed the settings in Roon to play through the A-S801—a very straightforward procedure. Usually, a Windows driver installation actually installs several drivers, such as a Windows Audio Session API (WASAPI) driver and an Audio Stream Input/Output (ASIO) driver and possibly others. Normally, I use the WASAPI driver; however, Yamaha’s WASAPI driver was buggy; it crashed a few times, and when it did work, it would not play DSD files, converting them instead to PCM, even though I had set Roon’s DSD playback strategy to play DSD files using DoP mode. Fortunately, the Yamaha ASIO driver worked just fine. To explore this problem, I also tried the drivers in the JRiver Media Center version 21 server program; again, the WASAPI driver crashed occasionally, while the ASIO driver worked OK. The Linux-based Aurender server worked flawlessly. Grrr—whereas I found dealing with such a problem an interesting challenge, it would have been very frustrating for a newbie.
The A-S801 epitomized the need for amplifier break-in. Yamaha recommended 100 hours, so I let the amplifier play 24/7 until it reached (and passed) that elapsed time before I started listening critically. When I first connected the A-S801, I feared the review was going to be an ordeal; the amplifier sounded brittle and raw; but after 100 hours of play, it smoothed out dramatically. A couple of audio dealer friends who heard the amplifier before and after break-in (but not in-between) agreed there was a big improvement. Since I’m a headphone fan, I made sure the headphone jack got plenty of break-in time, too, using $299 NAD VISO PM50 headphones, a good match for the Yamaha.
Lots of people have large music collections on their smartphones, so it’s handy to be able to play that music by connecting the phones to an amplifier using a wireless Bluetooth connection. I plugged Yamaha’s YBA-11 Bluetooth wireless adapter into the digital coaxial input jack to provide Bluetooth connectivity. As noted above, the A-S801 provides a Type A USB port on the rear panel that powers the adapter. Both a power cable and a skinny SPDIF cable are also provided. They aren’t very long, so you’ll need to place the adapter near the amplifier—not much farther away than the front panel. Connecting the YBA-11 to my iPhone 6 was quite easy. It was one of the best-sounding Bluetooth connections I’ve heard, too—very enjoyable.
The remote control was easy to use, with buttons to raise or lower the volume separated slightly from the other buttons for easier access. A mute button, just below the volume buttons, partially muted the output of the amplifier, letting the music play at a much reduced level. The muting was quiet enough to permit a telephone call or conversation, but loud enough to remind you music was still on. I was pleased to see that each input had a separate button on the remote, so you could access any input directly without having to scroll through intermediate ones. The source selector knob on the A-S801 was freely rotating, but had a detent at each input’s position, and a small LED lighted up at each position to indicate which input was selected. The volume control had a small index line inscribed on it, indicating its position, but it was a bit difficult to see from my listening position ten feet away. The volume control was a continuously variable unit with a motor drive that enabled the remote to set the level. The power amp section turned off when headphones were plugged in. I wondered if the relatively low headphone output into low-impedance ’phones would pose a problem, but it drove the 32-ohm NAD PM50s to higher SPLs than I cared to hear. The NAD headphone is quite an easy load, so I challenged the A-S801 with the harder-to-drive 35-ohm HiFiMan HE400, which has a fairly low 92.5dB sensitivity. The A-S801 drove it louder than I could stand to listen to, so any worries I might have had about wimpiness from the headphone amplifier were put to rest. Similarly, in my largish room (23' by 20' by 12') the A-S801 effortlessly drove the 85dB-sensitive KEF speakers much louder than I wanted to hear them play. Bass without the subwoofer was punchy and dynamic, although it understandably didn’t plumb the depths; after all, the KEF speakers only have a 5¼-inch mid/woofer—although sometimes the bass performance compelled me to check to make sure I hadn’t left the subwoofer on. The A-S801 had no problem driving my sub, though I had to turn it down considerably from the setting I normally use with my preamp.
Unfortunately, I didn’t have a moving-magnet cartridge available, so was unable to try the phono section. Nor did I have a CD player, which prevented using the CD Direct feature, but I did try the Pure Direct setting, which sounded a bit cleaner. I used the Pure Direct setting for the review.
The Yamaha A-S801 amplifier sounded sweet and smooth, particularly with vocals. Not a trace of the glare that plagued the unit before break-in was present, until the volume was advanced to a louder level than I ever cared to listen; then, some glare and coarseness set in.
It’s useful to begin a review with a very familiar musical piece, so I queued up old favorite “Folia Rodrigo Martinez” ripped as an AIFF file from the CD La Folia 1490-1701 [Alia Vox]. It’s an information-rich recording of a musical piece written in 1490 and realized by Jordi Savall and his band. On the A-S801, the cascabels which open the piece were very clearly delineated, though without as much detail as I’ve heard on the best systems. The bass, which descends into the mid-20Hz range, was, of course, not fully developed on the small KEF speakers (with subwoofer off), but had plenty of impact, and the upper bass was quite detailed. When I switched on the subwoofer, the low bass was reproduced with impact, though it lacked the resolution I’m used to hearing. Percussion instruments sounded harmonically accurate, but blurred into the background a bit more than they do with top-of-the-line systems. Savall’s viola da gamba sounded harmonically rich, and the baroque guitar and harp were distinctive. Sometimes the last two instruments seem to sound quite similar, making it hard to tell them apart. The A-S801 had plenty of microdynamic verve, so the music sounded quite lively. I could tell Savall and his forces were having lots of fun playing the piece, and I had just as much fun listening to it.