For years Yamaha has been well known for manufacturing high-value, feature-packed AV receivers. My first experience with the Yamaha brand was with the DSP-A1 in the late 90s, a seven-channel integrated amplifier with Yamaha's "Digital Sound Field Processing" to re-create the acoustic spaces of various concert halls, churches, and commercial movie theaters. The DSP-A1 was a great component that largely succeeded in re-creating these different listening environments, depending on the individual recording.

Yamaha is perhaps less well known for its HiFi component line, at least in the United States. The line includes stereo integrated amplifiers, receivers, CD players, and network players. To illustrate just how serious Yamaha is about two-channel music, the company introduced two statement pieces back in 2013 to highlight its new "Natural Sound," including the A-S3000 integrated amplifier and the CD-S3000 CD/SACD player. These two bad boys carry a combined suggested retail price of $15,000! At the very end of 2014, Yamaha sent me the new baby brothers to these flagships: the A-S2100 integrated amplifier ($3,999) and the companion CD-S2100 CD/SACD player ($3,499). While these pieces are not inexpensive, the good news is that Yamaha managed to incorporate most of the technology of the flagship products into the A-S2100 and CD-S2100 at half the price. I love it when technology trickles down from a company's more expensive products, avoiding the usual R&D costs that are added to the price. The A-S2100 integrated amplifier is the subject of this review, and a review of the CD-S2100 CD/SACD player is coming soon.

While integrated amplifiers have been around for decades, there was a period of time where they carried the moniker of "compromise product" and were avoided by so-called serious audiophiles. During that time, separates were considered the only path to true high-end sound. Lately, though, it seems that integrated amplifiers have enjoyed a resurgence in credibility with audiophiles. Many enthusiasts today are looking to get back to basics, and even ultra-high-end manufacturers like Boulder, Constellation, Soulution, and D'Agostino Master Audio Systems now offer integrated amplifiers in their product lines.

The A-S2100 is a product aimed squarely at serious audiophiles. This is no bargain-basement, lightweight product. The quality design and craftsmanship are immediately evident. Just taking it out of the box, you'll notice the heft of its 51.6 pounds. Underneath the amp's casework, the electronics are designed and constructed for right-left symmetry to optimize the separation of the right and left channels and the resulting stereo reproduction. The substantial power supply is located in the middle, with the power amp blocks found on the ends.

On the outside, the A-S2100 sports a retro aesthetic. It has a quarter-inch-thick milled aluminum faceplate with a brushed finish, available in either black or silver. The sample sent to me had a black faceplate. My impression of the black A-S2100 is one of understated elegance, while the silver faceplate adds additional pop to the A-S2100's appearance. Your preference will depend on how much you want the piece to stand out in your room. Both color options come with piano-black wood sides, a very cool retro touch. The unit is supported by high-quality spiked feet to provide isolation. The spikes can be covered by included magnetic pads to protect fine furniture. The feet can also be adjusted to level the unit if necessary.

The A-S2100's front panel features flush-mounted stereo analog VU level meters, reminiscent of amplifiers of the 70s and 80s. The knobs and switches are machined aluminum, giving them a very solid look and feel. A headphone input is found on the front panel to connect a pair of headphones to the discrete headphone amplifier circuit with low impedance drive. There is a corresponding trim selector that adjusts the volume level for headphones of different impedances to prevent sudden changes in volume. This is a really nice feature that's not commonly found on competing products.

Connections on the back panel are all logically laid out, with plenty of spacing between connectors for easy connection. There are two sets of uniquely designed brass speaker connectors symmetrically laid out and enabling solid connection with ease, no matter the gauge of speaker wire or whether using spades, bananas, or even bare wire. These are some of the best speaker connectors I've seen. Other manufacturers could take a lesson from Yamaha's unique design. Built with a fully floating and balanced circuit design, the A-S2100 has a set of balanced input jacks on the back panel to take full advantage of the design. There are also attenuator and phase selector switches that can be set for the component being connected to the balanced inputs. There are three sets of unbalanced input jacks for connecting additional components, as well as playback and record input jacks for connecting a CD recorder or tape deck. One set of Main In jacks allow for connection of a component with volume control. When the Main In jacks are selected from the source selector knob, the volume control of the A-S2100 remains fixed. There is also a set of Pre Out jacks for connecting an active subwoofer or another amplifier. In addition, trigger and remote control jacks are available, as is a power standby switch that, when selected, will automatically put the unit into standby mode when no signal has been input for eight hours.

Keeping in mind that audiophiles are the primary target market for the A-S2100 and turntables are making a comeback, Yamaha has strategically included input jacks for connecting a turntable. There is a high-quality, discrete phono amp circuit built into the A-S2100 with an MM/MC selector switch on the front panel to accommodate turntables with either cartridge type. The A-S2100 lacks a built-in DAC; however, at this price point, Yamaha is probably betting that potential buyers already own a standalone DAC or another component with a DAC, including many current CD players.

The remote control has an elegant brushed-aluminum finish. Its slender form factor and balanced weighting allow it to fit comfortably in the hand, and it includes power, input, CD control, tuner control, volume, and mute buttons. The remote can deliver large volume changes via the electronic volume control of the amp. While this can be a plus, I found that the individual steps in volume change were a bit larger than I would have liked. Sometimes I found it difficult to set the volume for a track to just the right level when using the remote.

The Hookup
I first took out the owner's manual and read through it before making the necessary connections. I know that one advantage of integrated amplifiers is the ease of connection to other components, but I always like to look through the manual of a product under review. The Yamaha manual is logically laid out and well written, and it includes detailed instructions on connections. The manual also contains detailed specifications, thoughtfully including block diagrams, and graphs for those who are interested.

I connected the A-S2100 integrated to my reference gear, including Aerial Acoustics 7T speakers, an Oppo BDP-105 Blu-ray player, and a Rega RP3 turntable with Elys2 cartridge. I also swapped the Yamaha CD-S2100 disc player for the Oppo disc player halfway through the review period. In addition to spinning discs, I streamed digital music files from the new Tidal music streaming service (review coming soon) and JRiver software via a connected Mac Mini music server. Digital files were decoded using the internal DACs in the Oppo and Yamaha disc players. Speaker and component connections were made using cabling from WireWorld.

Performance
I've got to admit that, going into this review, I was really curious whether the A-S2100 integrated amplifier's rated power output of 90 watts per channel (eight ohms, 20 Hz to 20 kHz) would be adequate to reproduce realistic bass dynamics from bass-heavy music selections, but I'll get into that more in a bit. After allowing a couple of weeks for break-in, I was ready to get down to business.

I suspect that many prospective buyers of this integrated amp probably have a turntable, so I decided to start things off by listening to some vinyl. I wanted to see whether the included phono amp was indeed a quality stage or just a cheap accessory for marketing purposes. I'll be the first to admit that, until recently, I was exclusively a digital guy, having moved on from vinyl a number of years ago. But with the recent renewed interest in vinyl by music enthusiasts (both young and not so young), I recently picked up a new Rega turntable as a review tool. Well, I can tell you that, while listening to the track "Surfer Girl" on the recent re-mastering of the Beach Boys' album of the same name (Analogue Productions), I was taken aback by just how good the Beach Boys sounded with the Yamaha amp. All of the dynamics, rhythm, and pace available on this recording came through, compliments of the Yamaha's phono stage. By the time the third track "Surfer Moon" was playing, I was mentally transported to the beach while enjoying the ultra-smooth texture of the vocal. Although I hadn't intended to, I listened to the whole album and several more. Maybe I need to give this vinyl thing another chance. No matter the LP I listened to, the Yamaha's phono stage turned out to be a great match with the Rega RP3 table. I suspect it would be great with other tables of similar quality, too. My past experience tells me that the Yamaha's phono stage would match or even beat quality standalone stages in the $300 to $500 price range, and having a built-in stage saves you the additional cost and complexity of another set of cables.

Okay, so far so good. Now it was time to move from analog to digital music. I decided to first check out the headphone output. I plugged in my Sennheiser HD 650 headphones and sat back to listen to several tunes I know quite well. I set the headphone amp trim control to closely match the headphone volume level with that of the speakers. When I played the track "I've Got You Under My Skin" on the stereo SACD When I Look In Your Eyes by Diana Krall (Verve Music Group), the Yamaha integrated amp presented the timbre of Diana's voice just as I remember it from her live concert at the Hollywood Bowl. The low noise floor that the Yamaha provided enabled all of the nuances of this laidback number to be clearly resolved. From the leading and trailing edges of the vibraphone's notes to Diana's breathing to the soft rap of the bongos in the background, the Yamaha made the lush presentation of this track so lifelike and realistic. The instruments along with Diana's breathy voice occupied their own distinct spaces within the soundstage.

Likewise, I called out the low noise floor in my notes while playing the track "Moonlight in Vermont" on the audiophile CD Ella and Louis by Ella Fitzgerald and Louis Armstrong (First Impression Music). The Yamaha's headphone amp was a sweet match for my Sennheisers.

To test the ability of the Yamaha to deliver realistic bass dynamics from more demanding music, I switched from headphones to speakers. I turned up the volume on the composition "Fanfare for the Common Man" on the CD Copland 100 (Reference Recordings) performed by the Minnesota Orchestra and conducted by Eiji Oue. The tympani were portrayed with the proper bass weight and impact to communicate the power and grandeur of this composition. The brass instruments were presented in an expansive soundstage that similarly portrayed the size of the orchestra. The large-capacity power supply of the Yamaha amp really showed its mettle. I was left with goose bumps when the recording ended.

With the volume already up, I decided to switch things up and stream something a bit more current using Tidal. First up was the track "Earned It" from the Fifty Shades of Grey soundtrack (Republic Records) and performed by Canadian alternative R&B artist Abel Tesfaye, better known as The Weeknd. The Yamaha ably portrayed all of the impact of the bass notes that provide the foundation for this powerful track and kept it moving forward without ever showing the slightest hint of strain.

Keeping within this genre, another memorable tune was "The Worst" by Los Angeles singer/songwriter Jhené Aiko from her EP Sail Out (Def Jam Recordings). This sultry, laidback number begins with a simple piano intro accompanied by a drum kit. For amps that lack sufficient headroom, the piano and bass drum can be challenging instruments to reproduce in a lifelike manner, but that wasn't a problem for the Yamaha. The buildup and decay of notes on the piano were palpable, and this amp had the chops to deliver bass notes from the drum kit with balance and fullness, but without any of the bass muddiness that can be present with lesser amps. The same held true even as I listened to a variety of even more bass-heavy tunes. Well done, Yamaha!

The Downside
While no product is perfect, I only have a couple of minor quips with the Yamaha A-S2100 integrated amp. First, when using the remote control, the Yamaha is set up to be able to make large volume changes quickly. In order to provide this capability, the remote makes fairly large individual volume step changes with each press of the volume button. This can make it difficult to set the volume to the optimal level using the remote.

Second, there is no visual display of the volume level on the front panel. While this feature is not often found on integrated amps, it could be a concern with the A-S2100 because the amp saves the volume setting from the previous listening session. The user could be surprised by an unexpectedly high volume when starting to play music the next time the unit is powered up. Learning to lower the volume before putting the amp in standby at the end of each listening session will avoid any such surprises.

Comparison and Competition
Potential buyers of the Yamaha A-S2100 have several other notable stereo integrated amplifier options to choose from, including the Parasound Halo 2.1, the Marantz PM11S3, the Bryston B135, the NAD C 390DD, and the Hegel H160. Pricewise, the Yamaha falls in the middle of this group of integrated amps. Each of these models incorporates a slightly different feature set. Some of these models have a phono stage and/or DAC built in, while others offer one or both features as optional add-ons. Of this group of integrated amps, I've had the chance to listen to music through both the Marantz and the Hegel models, but I have not had the chance to do a side-by-side comparison. In my opinion, the Yamaha is a very worthy competitor to these models. The integrated amp that's ultimately best for you will depend on both your individual sound preferences and the feature set that meets your needs.

Conclusion
The Yamaha A-S2100 is a serious integrated amplifier with a retro look for serious music enthusiasts. Yamaha delivers on its promise of "Natural Sound" with its full floating and balanced circuit design incorporated into the A-S2100. The A-S2100 is a great match for two-channel enthusiasts who like to spin silver discs and also have a penchant for vinyl or headphone listening, but who don't require a built-in DAC. If that describes you, I strongly suggest you check out the Yamaha A-S2100 integrated amplifier. You'll be glad you did!

Additional Resources
• Yamaha Aventage RX-A3040 AV Receiver Reviewed at HomeTheaterReview.com.
• Yamaha Announces Four New Integrated Amplifiers at HomeTheaterReview.com.
• Check out our Stereo, Mono, and Audiophile Amplifiers category page for similar reviews.