Country of Origin


Super 211 SET

Reviewer: Terry London
Financial interests: Director of the Chicago Institute for R. E. B. T. & Clinical Director for the Above and Beyond Family Recovery Center in Chicago
Sources: Lab 12-DAC1, CEC TL3N Transport
Power amplifiers: Bricasti Design M15, Coda NO.8, Triode Lab SET 2A3, Linear Tube Audio Ultralinear, Threshold Stasis 2, Threshold 400A
Loudspeakers: NSMT Model 50, Tekton Design Perfect SET, Tekton Design Ulfberth, Tekton Design Moab [on review]
Cables: Sablon Audio Corona S/PDIF, full loom of Black Cat Audio Coppertone IC and speaker wire
Power delivery: Running Springs Audio Dmitri power conditioner, Dignity Audio PPT-50/two 250 transformers, Audio Archon power cords
Equipment rack: Smith Design 2-tier basic rack, bamboo boards, Krolo Design reference footers
Review component retail: $12'500 with all the necessary tubes

A year and a half ago I was a staff reviewer at HomeTheaterReview.com. There I received numerous emails inquiring whether I could review an amplifier from Aric Audio in Palmer, Massachusetts. This reader interest stemmed from three factors. CEO/designer Aric Kimball had a reputation as a very creative designer of innovative tube circuits and as an artisan master builder of line stages and amplifiers. Secondly, many customers worked with him to upgrade or customize his models to get exactly what they look for in their systems. Lastly, his pricing was somewhat shocking for the quality of parts, construction and performance compared to other US-based tube electronics houses. I went on to review Aric's Transcend Series KT120 SE and Transcend Push-Pull amplifiers. Each received superlative marks for excellent performance with many different speakers I had in-house. I actually purchased the KT120 SE sample and still loan it out whenever someone local is interested in a SET at a very reasonable price. Subsequently Aric and I had many discussions about our favorite tubes in a SET design. We both admire the 2A3. When I asked if he had ever heard a 211 SET, Aric hadn't. I shared how it was my personal favorite tube based on beautiful purity of tone, top-to-bottom linear extension and a subjective sense of emotional intimacy with the music just like a 2A3.

However, it adds a far more powerful overall sense of macro dynamics, deeper tauter bass control and drives many more speakers than the 3 watts of a 2A3 ever could. The average 211 SET usually offers 12-15wpc. Aric began a project to study all possible circuit topographies to see if he could come up with a way of driving the 211 for both higher power and maximized musical performance. I asked him to describe for us in detail what he came up with for his Super 211 SET regarding overall topography, parts selection, why he decided on specific tube types and how he developed his power supply.

"My inspiration: Having built many beautiful-sounding single-ended amplifiers, most require very efficient speakers to fall into the 'flea-watt' category of 3-8 watts. I also have built many single-ended amps around the KT tubes. While in ultra-linear mode the power for a KT150 can reach up to 25 watts, they lack that true direct-heated SET sound of the 2A3 and 300B. I really wanted to move up to the next level and build an amplifier that could drive real-world speakers of lower efficiency. I also wanted the sound of a 2A3 but with the power of a KT150. I knew that transmitter tubes like the 211 and 845 were the way to go but didn't want to build just another 211 or 845 amp. I wanted to make sure that I employed all of the parameters and covered all the bases to make sure these tubes truly sang. Their anode voltages had to be over 1'000V and the drivers had to be capable of swinging over 200 volts peak to peak. Otherwise, these tubes are under-utilized to never reach their full musical expression. I wanted to build an amplifier that fully realized what these tubes have to offer.