Friday, August 16, 2013

New Amp in the System--Unison Research S6

I just made another change to our reference system at CCI World Headquarters. I swapped out the Unison Research Sinfonia I've used for the last 18 months for another Unison integrated...the S6. The only reason I made the change was because we sold the Sinfonia as a demo piece to one of our dealers. The S6 I'm now using was the same one John Marks reviewed for Stereophile last month, so it's sort of a celebrity.

The S6 was the first Unison integrated amplifier with which I became familiar once Colleen and I started CCI in July of 2011. Although I've used numerous Unison amps in our home system and at trade shows over the last two plus years, the S6 might just be my overall favorite so far. It's an EL-34 based amplifier instead of a KT-88 based amplifier, such as the Sinfonia, which gives it a slightly more dynamic and modern tube amp sound. The Sinfonia was a warm, slightly lush-sounding tube amp that sounded a bit more old-fashioned than the S6. It was also slightly less powerful (27 wpc vs. the S6's 35 wpc) and yet slightly more expensive--mostly due to the more elaborate use of wood in the chassis and the more complex circuitry designed for the KT88s.

I quickly compared the two amps before I made the switch using a couple of CDs I just received from jazz pianist Todd Hunter (article/review coming soon). The Sinfonia might be slightly more refined and romantic, but the S6 is gutsy and powerful. In my rather large room with fairly sensitive speakers (the 89dB Opera Secondas), Todd's rich and lyrical piano sounded much more forceful and impressive. I have to admit that my new Colorado listening room is so big that some of my speakers are having trouble energizing its boundaries. Deep bass exists, but it doesn't quite hit you viscerally like it should. The S6 has eliminated this issue completely.

So welcome back, S6! I'll really miss the Sinfonia, but the new amp feels like an old that I've missed a lot.


  1. I auditioned both the Sinfonia and the S6 a number of times. Preferred the Sinfonia over the over the S6. Well the Sinfonia does offer up a lot refinement and romance sonically.... it has some serious Cajones as well, for lack of a better term.The Sinfonia has an amazing way of reproducing the natural timbres of Brass, Reed , Stringed instruments and the human voice.I thought it was superior to the S6 in this regard. IMO. Important, especially if you listen to a lot Jazz music . I purchased the Sinfonia to go along with my Harbeth 30.1. Match made heaven . Thank you Unison !!!

    1. I have the s6 and also the sinfonia prefer the s6 any comments welcome

  2. I have the s6 and the sinfonia my room is 15ft by 15ft overall the s6 blows the sinfonia away the mid range on the s6 are fantastic love to here other points of view I use zinngalli speakers 93 sensitivity looking forward to comments andy