 December 2008
Torus Power RM 15 Power Conditioner
by Doug Blackburn
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Review Summary
| Sound |
"Compared to
wall-outlet sound, the sound with the RM 15 was much larger in every direction, filling the
room from wall to wall, nearly floor to ceiling and with a good sense of depth that was almost
entirely missing with wall-outlet power. There was a complete restoration of musical
qualities; the pace of the music was compelling, there was a fuller harmonic spectrum for each
instrument or vocalist, and, of course, there was a quieter background and a sense of
increased space." "Acoustic instruments were much more convincing and nuanced with
the RM 15. Variations in the sharpness of plucked strings became easy to pick out." |
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| Features |
"Torus Power
products are interesting in that there’s nothing inside the chassis except a huge
isolation transformer, the wiring, the backside of the AC outlets, the surge suppression
devices, and a few control components. There are no conventional filter networks anywhere.
Torus Power took a unique approach by working with Plitron, a transformer manufacturer, to
create an isolation transformer that doesn’t behave like a conventional toroidal
transformer." "The back panel contains ten AC outlets, a ground post, and an IEC
socket for the power cord." |
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| Use |
"None of the
hospital-grade outlets is labeled for use with an amplifier, a digital device, a video device
or any of the other specific types of equipment. This is because there is a single output from
the secondary side of the isolation transformer with all the outlets connected in parallel.
This means all the outlets have equal current capability and it doesn’t matter what
components are connected to which outlets." |
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| Value |
"The RM 15’s
silent operation and easy-to-hear sonic improvement definitely make it worthy of
consideration." |
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Torus Power has a new approach to power
conditioning and isolation. In their estimation, isolation from the power line is one of
the keys to success for high-performance power-conditioning products for home systems. To
that end, Torus Power offers four product lines comprising 19 different models. The 15-amp
rack-mount unit, RM 15 ($2800 USD), provided for this review is part of a family of models
with prices from $995 for the 2.5-amp model up to $3000 for the 20-amp model. Two of the
other three product lines are more specialized isolation products requiring 240VAC
two-phase power. Many newer homes have 100-amp electrical panels, while 200-amp panels (or
greater) are found in larger homes with more luxury equipment (outdoor lighting systems,
swimming pools, large air conditioning units and electric furnaces), so Torus Power's
wall-mount isolation units could potentially be used for the whole house. The remaining
product line features "box style" units that will appeal to many, with their
black chassis and simple silver faceplate and no rack ears. These will look right at home
in a typical equipment rack for a home-audio or home-theater system. Thus, with all of its
product lines, Torus Power has covered just about every consumer base.
Torus Power products are interesting in that
there’s nothing inside the chassis except a huge isolation transformer, the wiring,
the backside of the AC outlets, the surge suppression devices, and a few control
components (voltage regulation will be introduced soon). There are no conventional filter
networks anywhere. Torus Power took a unique approach by working with Plitron, a
transformer manufacturer, to create an isolation transformer that doesn’t behave like
a conventional toroidal transformer. Toroids, as commonly used and specified, do little to
block high-frequency noise on the power line in either direction. The isolation toroids
Torus Power uses have special design features that address higher frequencies, beginning
at 2000Hz. This is a much lower frequency than you find for typical conventional power
conditioners that have filter networks using capacitors or capacitors and inductors.
According to provided specifications, noise
reduction for the Torus Power units is just beginning at 2000Hz. At 20,000Hz there’s
about 12dB of noise reduction. At 200,000Hz, noise is reduced by about 24dB. Near
500,000Hz, noise reduction peaks at 36-40dB. It then slowly diminishes as frequencies
increase to 2MHz, where it levels off at about 20dB. Torus Power’s numbers are better
than those for many capacitor-based power conditioners below 100,000Hz. Above 100,000Hz,
it’s not uncommon to find similar noise-reduction capabilities in other products. Of
course, the capacitor-based products don’t isolate connected components from the
power line as do the Torus Power products.
Unlike most other power conditioners, there are
no capacitors used as filters in the Torus Power products. This has the hypothetical
benefit of eliminating dielectric (insulator) memory from smearing audio quality. Many
have speculated that the relatively large amounts of dielectric in capacitors used in
power conditioners actually retains some memory of immediately preceding audio signals.
Eliminating the capacitors, then, should remove any possibility of capacitors in a power
conditioner having a negative impact on sound quality.
Product features and description
The RM 15 is one of the larger rack-mount units,
measuring 19"W x 6 1/4"H x 17"D. Its fascia is black with a curved
brushed-silver center section that matches the shape of the curve of the transformer
inside behind the faceplate. The faceplate has an internally illuminated on/off rocker
switch, and the Torus Power logo is engraved in the curved silver center section. The rack
ears are an integral part of the faceplate, helping the unit to look quite good resting on
an equipment-rack shelf.
The back panel contains ten AC outlets, a ground
post, and an IEC socket for the power cord. Toroidal transformers large enough to deliver
the rated 15 amps are large and heavy, accounting for most of the RM 15's 76 pounds. The
transformer is claimed to have design features that make it silent while operating. I
never detected any noise, something that cannot be said for some other power-conditioning
products employing transformers (balanced-power products primarily).
None of the hospital-grade outlets is labeled for
use with an amplifier, a digital device, a video device or any of the other specific types
of equipment. This is because there is a single output from the secondary side of the
isolation transformer with all the outlets connected in parallel. This means all the
outlets have equal current capability and it doesn’t matter which components are
connected to which outlets. Most conventional power conditioners have a filter network for
each pair of AC outlets, while a few have a filter for four outlets, and others have
filters for each individual outlet. This filtering is said to help remove noise generated
by the connected components themselves. Torus Power has chosen not to add any additional
filtering to outlet groups, pairs, or single outlets, relying on the isolation transformer
to do all the filtering.
Reference system
I’ve been using the components in my
reference system for many years. Being so familiar with this system makes it relatively
easy to detect even small changes in sound -- for better or worse.
The main speakers are Vandersteen 3A Signatures
with a pair of Vandersteen 2Wq subwoofers to extend bass to 20Hz. A Belles 350A Reference
250Wpc solid-state stereo amp drives the Vandersteen speakers. The preamp is the Belles
Modules 28A solid-state preamp with moving-coil phono stage. The CD transport is the
now-venerable Pioneer DV-525 DVD player with extensive mods to make it especially
effective as a CD transport, including a replacement master clock. Digital audio
processing is done by the Perpetual Technologies P-1A digital correction unit and P-3A
DAC, both fed by a Monolithic power supply. LPs were played on a Roksan Xerxes turntable
with a rewired SME V tonearm and a Cardas Heart ultra-low-output moving-coil cartridge.
Power cords were all Audience e-series
powerChords. Speaker cables were Magnan Signature or Audience Au24e, analog interconnects
were Audience Au24e and Magnan Signature, and digital interconnects were Audience Au24e.
When the RM 15 was added to my system, it powered all components, including the amplifier.
Listening impressions
As usual, I cleansed my palate, so to speak,
connecting my system directly to the wall outlet before introducing the RM 15. And, as
usual, the sound with my system powered this way was quite disappointing -- dark, cloudy,
flat and ill-defined. The best my system could muster in terms of soundstaging was an
image the size of a small ball floating between the two speakers. This has always been my
experience with wall-outlet power, whether in New York, where I used to live, or now in
Colorado. But I keep checking, just to be sure. Frankly, I can’t imagine anybody
being satisfied with wall-outlet power. Perhaps there are some rare components out there
designed to sound great with power from the wall, but this certainly hasn’t been my
experience with typical audio or home-theater products.
| Torus Power BX 10 Torus Power also sent a BX 10 10-amp unit ($1900) for evaluation.
The BX-series units are 120VAC models with peak current specs of 2.5 amps, 5 amps, or 10
amps. Prices range from $1100 to $1900. The features are the same; they're just
packaged a little differently.
With the entire system connected, the BX-10 was definitely
doing a little current limiting for the big Belles 350A Reference amp, softening dynamics
a bit. Changing to a 125Wpc amp eliminated any noticeable limiting of dynamics.
Another listening evaluation was done with the BX 10
powering everything but the amplifier and the RM 15 powering the amp. This reduced the
load on the two Torus Power units and added a degree of isolation between the source
components and amplifier. I detected just a bit more dynamic punch and a little more
background silence by using both units. The real question here is whether the BX 10/RM 15
combo was worth $1900 more than the $2800 RM 15 alone. I’d say no. Source components
(turntable, DAC, digital processor, preamp, transport) don’t need more than a 2.5-amp
model, which costs $1100. That’s reasonable enough to be worthy of consideration for
the improvement provided here.
A third evaluation was performed using the BX 10 to power
all the source components, while the big stereo amp was connected directly to the wall
outlet. Though it may sound like a good idea, it turns out to be a pretty dismal
compromise. Too much character of unconditioned power seeped back into the system, which
resulted in a small, congested soundfield and a noticeably dull character. If you are
going to add power conditioning, you may as well do it right: Plan on enough power
capacity so that amplifiers can be connected to the power conditioner too.
...Doug Blackburn
db@soundstage.com |
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For the first day or two after adding the RM 15,
the sound was congested, displaying a small soundfield. After that, the soundfield opened
up considerably. I did not notice a significant change in sound after the second day of
use. Compared to wall-outlet sound, the sound with the RM 15 was much larger in every
direction, filling the room from wall to wall, nearly floor to ceiling and with a good
sense of depth that was almost entirely missing with wall-outlet power. There was a
complete restoration of musical qualities; the pace of the music was compelling, there was
a fuller harmonic spectrum for each instrument or vocalist, and, of course, a quieter
background and a sense of increased space. It was a return to that satisfyingly complete
sound that let me know the system was getting more things right than wrong. As the weeks
progressed, I found myself really enjoying the improvements over the wall-outlet sound.
Cat Stevens’ Year of the Cat CD
(Rhino R2 78065) was greatly improved, with instruments well separated and a notable sense
that the music existed in 3-D space, even though the effect was created by master engineer
Alan Parsons. Acoustic instruments were much more convincing and nuanced with the RM 15.
Variations in the sharpness of plucked strings became easy to pick out.
On more complex material like Brian Wilson’s
CD Smile (Nonesuch 79846-2), the ability to hear individual instruments within the
mix was much improved. Wall-outlet power produced a sonic mush with so many sounds
overlapping and colliding that hearing into the mix was fairly difficult and unrewarding.
The two bookend pieces, "Heroes and Villains" and "Good Vibrations,"
grew in size in every dimension, spreading out instruments and vocals so that you could
hear each element with relative ease.
The power straight from the outlet left me
feeling like I was being blocked from enjoying the music, because the big, complex mix was
squashed into a small flattened sphere between the speakers. With the RM 15 in the system,
I felt like the sound had been let out of jail. Its spirit was whole again, and it soared
and emoted in ways that the system was simply not capable of otherwise. The 12" 45rpm
single of The Art of Noise's (with Tom Jones) "Kiss" (UK Polydor/China CHINX 11
871 039-1) was merely OK with unconditioned power. With the RM 15 powering the system, it
became a bona fide entertainment experience with an irresistibly powerful beat, a
room-filling soundfield, spectacular dynamics, and excellent space and separation of sonic
elements, even though the recording is a mostly electronic creation.
In the end, it was rather easy to hear the RM
15's effect. Instruments and vocalists sounded more delineated within a larger space, the
consequence of noise being reduced to the betterment of the music. What's not to like
about all of that?
Comparison
Each time I compare power conditioners in
succession, there is a period of about an hour where the system sounds a bit off compared
to how it sounded with the previous power conditioner. To avoid being influenced by that
transition time, I always allow at least two hours of operation before performing any
evaluations. There just is no rushing when it comes to evaluating power products.
So out went the Torus Power RM 15 and in came
ExactPower EP15A ($2500), an active product that samples the power line at very high
frequencies, removing anything that shouldn’t be present and reconstructing an
essentially perfect 60Hz 120VAC sine wave. The EP15A provides voltage regulation,
extremely high wideband noise reduction (110dB specification), and very low total
distortion (below 0.2%). In addition, the EP15A can deliver up to 46 amps to meet
short-duration current demands, even though it is connected to a 15-amp AC outlet. EP15A
was named a SoundStage! Reviewers’ Choice in 2003, and it's one of the best
units in its very crowded price range.
The EP15A produced a lower noise floor with a
heightened sense of silence between notes and between tracks. It required extremely quiet
listening conditions to pick this up, but it was clearly audible. The RM 15 produced a
more silent noise floor than wall-outlet power, but it couldn’t equal the inky-black
noise floor of the EP15A. Without the direct comparison, I don’t think I ever would
have known there was a difference. Both units produced a pleasing musical experience, but
the EP15A is a little more dynamic with a larger soundfield, a little more detail and some
harmonic richness that’s not present with the Torus Power unit. Finally, the
system’s bass reproduction with the EP15A was more controlled and defined -- tighter
with less upper-bass fullness. The Torus Power unit’s bass was strong and deep, but a
little fuller and warmer. The EP15A produces a fair amount of heat while operating a
system with a 250Wpc stereo amplifier at reasonable listening levels, while the RM 15
operates so close to room temperature that I couldn’t detect any heat at all.
Substituting Equi=Tech’s Son Of Q Jr. and
Son of Q balanced-power conditioners ($2500 for the pair) for the RM 15 produced a blacker
noise floor with about the same sense of musicality and space as the RM 15. However, the
transformers in the Equi=Tech units produced a low-level audible hum that could be heard
from six or seven feet away, while the RM 15 was silent in operation.
As with other kinds of audio equipment, power
conditioners use varied technologies to arrive at the same claimed end product: sound
that's more realistic. The Torus Power RM 15 held its own among some stiff competition.
Conclusion
Torus Power’s new take on power conditioning
proved effective in making easy-to-hear sonic improvement compared to unconditioned,
straight-from-the-wall power. While offering permanent, non-degrading surge and spike
protection, noise reduction, and power-line isolation, the RM 15 does not provide
component isolation, voltage regulation or balanced power. While I thought ExactPower
EP15A sounded a little better in my system, keep in mind that power conditioners often
return different results in different systems and locations. Still, the RM 15’s
silent operation and easy-to-hear sonic improvement definitely make it worthy of
consideration.
...Doug Blackburn
db@soundstage.com
Torus Power RM 15 Power Conditioner
Price: $2800 USD.
Warranty: Five years parts and labor.Torus Power
P.O. Box 30030
Toronto, ON M3J 3L6 Canada
Phone: (416) 667-8473
Website: www.toruspower.com
Worldwide sales:
Bryston Limited
P.O. Box 2170
677 Neal Drive
Peterborough, Ontario, Canada K9J 7Y4
Phone: (705) 742-5325
Fax: (705) 742-0882
E-mail: jamestanner@bryston.ca
Website: www.bryston.ca |
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