SBS Designs: S2 stereo amplifier

Getting prepped for this review was something of a unique experience. For the first time in five or six years of doing reviews for Tape Op, the founder of a company wanted to speak live over the phone to me. Sounds mundane enough - but that one event speaks volumes for the way my entire experience with the SBS Designs S2 would go. What ensued was an hour-long conversation about music, night clubs, and audio fidelity in general. Craig "Shorty" Bernabeu is outspoken, personable, and super knowledgeable. He feels an obvious joy for music, and his goal is to make it sound pristine. With a pronounced New Jersey accent and a voice that's probably 3 dB louder than most, Craig filled me in on the SBS Designs vibe - no-compromise audio fidelity and build quality. Craig's been doing sound-system design and implementation around the globe since 1985 and has won many awards along the way. If you've never heard of SBS Designs, it's because the company's products are relative newcomers. The S2 is only three years old. It was born out of a desire to counteract a trend that Craig noticed in the industry towards "commercial, loud, bad systems," which he attributes to a blind focus on paper specs, overly-used digital processing, and poor build quality

According to the SBS Designs website, the S2 is "a super high quality stereo amplifier voiced to be extremely fast, very dynamic, and true to the source while maintaining a very open and musical sound." After my weeks with the S2, I think that statement is spot-on. The amp is aimed at pro studio, large PA venues (like nightclubs), and home audiophile environments - so it's got a good bit of competition to nudge out of the way. But the timing seems to be right. Audio trends definitely seem to be coming back around to great sound rather than in-the-box convenience, and that's a good environment for a company like SBS Designs. Their zero-compromise philosophy is important since amplifier performance can't be measured simply in watts. If you're using passive speakers, then the amplifier is going to determine how well the speakers are able to recreate the audio signal. Qualities like slew rate, damping factor, distortion, heat dissipation, quality of internal components, and even copper trace spacing will all impact how well the speaker can translate that audio signal into actual sound waves - and these are all things that SBS Designs said they've specifically aimed to do best.

To get a feel for the amp, I hooked up the S2 to pairs of Yamaha NS10M Studio and B&W DM 303 speakers and queued up a couple other amps for comparison. I think the two speaker choices represent a well-understood recording-studio rig and a home hi-fi setup fairly well. [For a fascinating historical and technical analysis of the NS10M design, and particularly its exemplary time-domain performance, read "The Yamaha NS10 Story" published in the September 2008 issue of Sound on Sound, available online at www.soundonsound.com. -AH]

I used to run the NS10Ms with a Bryston 2B LP, and one of the differences I noticed after a day with the S2 was that the room didn't heat up at all. I actually used to use the NS10Ms less, simply because I didn't want to deal with altering the room temperature. In fairness, the 2B LP is quite old, but it's still very much in use around the world. The DM 303s had been connected to a Rotel RA972 (not a peer of the S2, but a good representation of what a home hi-fi system might have in use). Another thing that was instantly apparent was how loud the S2 could perform. I forgot to check the gain levels on the back before hitting play the first time, and I think I might have filled my pants, because the music was so loud. I actually freaked so bad, I kept hitting the spacebar twice so the music would stop/start - and I'd just freak out again. Embarrassing. Once the gain was adjusted, I was able to change my pants and sit down to listen for a bit. The S2 generated an incredible sound stage. What sounded really flat on the Rotel became incredibly dynamic. On Adele's "Turning Tables," the piano, strings, and vocal all exploded into their own space. I could hear the piano sitting at the back of the track with great low-mid weight, and the strings off to one side and in the middle with tons of room to breathe. The vocal then had such an incredibly powerful presence. The listening experience was completely changed. As I auditioned more music, I noted that percussive elements across different genres became much tighter, much more controlled, and far more powerful. Kicks were cleaner and punchier. The overall sound was wide, dynamic, and really more comfortable to listen to. My experience was a great example of a quote from Craig: "Music and great sound is supposed to draw you in and make you forget about time, and make you not want to stop playing or making music". Indeed.

Just to see what a much larger amp might do in the same scenario, I grabbed a Crown K2 for testing. Though the K2 has four times the specified wattage per channel, the S2 sounded dramatically better in every way, on both the NS10Ms and the DM 303s. The K2 was loud, but highs were harsh and crispy, and mids and mid-highs were bright in an overdone sounding way. Although the K2's lower frequencies were powerful, they sounded looser and less controlled than the S2's. Overall, the soundstage of the K2 was greatly diminished, and its sound felt really fatiguing compared to the S2's.

I wanted to grab a 2B LP for reference since I don't have mine any longer, but I couldn't find one in time for this review. I ended up sourcing a Bryston 3B SST Pro, and the differences were interesting. To start, the two amps aren't intended to be peers. The 3B costs roughly $1,400 more than the S2, and as you'd expect, it has more power per channel (and a higher damping factor). That said, the difference in sound was much less pronounced than I thought it might be. The 3B pushed a bit more low end, and the soundstage was a bit wider, but the amps were close enough that I found myself forgetting which amp was plugged in. At least a few times I was thinking "yeah, that definitely sounds incredible" and looked down, and I was plugged into the S2. The 3B also heated up a bit while the S2 had absolutely no evidence it was even powered on in terms of heat. If you need an amp that's going to be pushing power for extended periods of time, then this could be a pretty big consideration. Craig at SBS Designs spoke about this specifically when telling me how they spec'd absolutely every part to fit the S2 exactly. The heat sink in particular was designed for this box to avoid the problems other amplifiers have of their sound changing as they heat up. SBS absolutely nailed this.

The SBS Designs S2 is clearly a top-shelf piece of gear. It's rock solid with a no-frills design, and it offers incredible results. Plus, it's handmade in USA and comes with a 10 year warranty. If you have any questions, SBS Designs founder Craig "Shorty" Bernabeu encourages you to email him directly.