Reprinted from Stereo Times, November 2012 by Written by Norm Luttbeg – Today’s review dear friends, is of the Torus Power RM-15 Plus power isolation transformer. It utilizes a unique toroidal transformer specifically designed for audio and video purposes by a company called Plitron Manufacturing. The Torus is the fifth isolation transformer unit that I have used and is clearly the best though many of those other transformers were used years ago. My unit was designed for 120 volt wall power, but others allow 240 volt wall input and 120 volt outputs.
This unit has 10 medical grade AC outlets that tightly grasped my AC plugs. The unit weighs just over 70 pounds and is 17 inches in width, 16 inches deep and 6.4 inches tall. It has an on/off switch and a heavy-duty AC power cord, though at the very beginning I did use an Exemplar Portal AC cord.
Torus makes every effort to keep the output impedance low (.2 Ohms), in addition to isolating the outputs from all line AC distortions. This allows for instantaneous peaks of 400 amps when needed and the dynamic headroom for big amplifiers was immediately evident using the Torus on both the amplifiers I used.
There is surge protection built into this unit using a patented series-made surge removal rather than MOVs. LoNo and Imin technologies are used to provide “unconstrained yet protected” AC for your system.
The System Used
My system includes the new B.M.C. Arcadia speakers, the Exemplar XP-2 tube line stage, and three different amplifiers–the LSA Statement Plus, which is a 150 watt and 78 pound stereo and integrated amplifier, BMC M2 200 watt monoblocks, and the 100 watt H-Cat DF-100.2 stereo amplifier. I mainly used the H-Cat and BMC amps. My analog rig is a Bergman Sindre turntable with the Ortofon A-90 cartridge. Digital sources are the Empirical Audio Music Server, Weiss DAC202 and Exemplar prototype DAC. Cabling consisted of Exemplar Portal long linear crystal silver ribbon interconnects and their copper powercords and speaker wires. Accessories included a Weizhi PRS-6 Power Distributor, HB Cable Designs PowerSlave Acrylic power distributor, and StillPoints Ultra SSs and Fives, Rack, new Grids that replace the acrylic shelves on their rack, and Component Stands. With a brief exception, the Torus was used on the StillPoints Component stand as this made moving it in and out of the system easier. When I first got it, I used it sitting on the floor. Not unexpectedly, it benefitted from the use of this stand.
After about two days of breaking in the Torus RM-15, I did a simple comparison of a line strip connected into the wall outlet versus into the Torus using the H-Cat amplifier and all my other components.
The noise level, soundstage imaging, and dynamics were immediately evident. I listened to the normal series of selections, starting with Sinatra’s “One for My Baby,” Holly Cole’s “Get Out of Town,” Ansermet’s “Swan Lake Duo,” Nelson and Marsalis’s “Stardust,” and Wasserman’s “Stardust.” The dynamics on the Holly Cole were striking as they also were on a new Diana Krall “Temptation” DSD cut.
Also, the noise threshold was much lower with the Torus. I had not listened to my lines directly in a long time. I really had not recalled how bad they were. Next came a comparison of the Torus with the Weizhi that I have been using for some time. The Weizhi is merely a six plug passive power strip but for some reason, perhaps the ground, sounds quite good. I know it is far superior to connect directly into the AC in the wall outlets. Once again the dynamics of the Torus were evident. Also I appreciate having more outlets than the six of the Weizhi. While I could hear a difference between the two devices, all that really stood out for me was the dynamics as well as the bass of the Torus. It was the same for both H-Cat and BMC amplifiers. I had to use a separate special prototype device for the digital sources given the few outlets on the Weizhi. Before moving on, I used this unit for the digital devices with the Torus also and didn’t think I heard any difference.
Early in the review I received a HB Cable Designs PowerSlave Acrylic power distributor. This is a European (Germany) design, which focuses on individual outlets, heavy gauge wire with all connections using silver solder with a special IEC connector. It also uses “special” materials as wraps around the wires for RFI and EMI shielding and vibration isolation. This power distributor needed its own break-in before it could be compared with the Torus. I also used the HB Cable Designs Dragon power cord.
This was a more difficult comparison. I still would give a very slight nod to the Torus in dynamics, but the PowerSlave had more detail, transparency, and general realism. I could hear a sharper attack and more of the ambience in the theater or studio. It also sounded faster. Of course with its own special power cord, it retails for three times the price of the Torus.
The Torus RM-15 Plus is the best sounding isolation transformer I have heard. I would put isolation under it and try other power cords. I live in an area with few industrial users but with many students using cell phones. I notice very little variation in voltage, but have seen much noise of the utilities talking on their power lines. The Torus isolated my equipment quite well from this noise.
Input current limiting: front panel on/off and circuit breaker
Load current capacity: ½ cycle 300 amps, 1 second: 150 amps, and 10 seconds: 75 amps
Input current Rating: 12 amps
Weight: 71 pounds
Dimensions: 17” w 16” d 6.4” h
Price: $2,895 with heavy duty power cord