A Discovery Article
SONIC FRONTIERS SFS-80 Stereo Tube Amp:
A Bargain Tube Amp For Serious Music Lovers
A Discovery Article
SONIC FRONTIERS SFS-80 Stereo Tube Amp:
A Bargain Tube Amp For Serious Music Lovers
SONIC FRONTIERS
is a relatively new audio company. Headquartered in Oakville, Ontario, Canada, the company
started in the late 80's selling audiophile-quality parts to hifi hobbyists who liked to
build or modify components, an endeavor it still continues through its Parts Connection
division. From there, the company introduced a kit for the Do-It-Yourself (DIY) market,
and finally graduated into assembling new components.
The SFS-80 Stereo Tube Amp
The SFS-80 is Sonic Frontiers' top of the line tube stereo amplifier. A rather hefty
unit, it is built like a tank and is likely to last like one. From its thick brushed stainless
steel chassis and transformer top covers, State of the Art passive parts quality (MIT MultiCap, Vishay, Holco, Cardas and
Edison-Price parts), 66 lbs weight, and massive transformers, one gets the accumulated impression
that this company builds serious audio equipment of industrial grade quality.
Features
An 80 watt vacuum tube stereo amplifier featuring a regulated pentode output
stage, the SFS-80 is said to also utilize a multi-secondary output transformer.
Twin 6DJ8 tubes comprise the input and driver stage. A front panel bias meter is provided
along with externally mounted adjustment
controls. This user friendly feature along with the instructions in the owner manual
allows even an amateur to bias this amp. I wish more tube amp manufacturers offered this
feature. I believe this will attract new tube amp ownership.
An open chassis design with metal cage as a safety implement, the SFS-80 is factory supplied with matched KT99's or KT88's depending upon the version. One may also use 6550/6550A, KT90 types, or EL34/6CA7 though the latter will reduce the available output by about 50% to 40 watts.
The amp comes with a detachable power cord, a boon for those who prefer to upgrade this later on.
Listening Experience
Frankly, I have had four SFS-80s pass through me. I can't resist a great deal when it's
occasionally presented. When Sonic Frontiers introduced their new models, some audiophiles decided
to get rid of their SFS-80. It is a typical reaction of a segment that always prefers
to have the latest gear. The particular unit under review was acquired from its
original owner who was very motivated to sell. It was consigned at dealer, and
had been languishing there for a number of weeks.
The following equipment were used to evaluate the SFS-80: Audible Illusions Modulus 3 tube preamplifier, Pink Triangle Turntable with Sumiko MMT and Promethean Green cartridge, JVC XL-Z1050 compact disk player all connected through an Inouye power conditioner, Classe DR-9 amp, ARC D-76 tube amp, Sound Dynamics 300Ti and Castle Isis speakers with Sound Anchor stands, Kimber 8TC speaker cables and MIT interconnects. Having had this system for many months, I am very familiar with the nuances brought about by additions or deletions from this system.
Personal Bias
In case this is your first time to read one of my reviews in the Audio Shopper,
let me state beforehand that I am an avid tube enthusiast, a position that I
gradually took after many years of experimentation, mistakes, and experience. Many
audiophiles that I know and communicate with have a similar view but lack the time,
knowledge, and commitment that tube component ownership requires and so they opt instead
for solid state. There is nothing wrong with that. What is intrinsically important is
that we get to enjoy the fruit of our aspiration--the music and various facets
of the audio.
So Here We Are with the SFS-80
Let me state at the outset that during my occasional ownership of SFS-80s, I have
also had the opportunity to compare them, albeit briefly, with other amps that I
had during the time. These include the ARC Classic 60, YBA Integre integrated amp,
VTL mono 100, 50 and 30 stereo tube amps. During those times I had always been
suitably impressed with the SFS-80 but had no compelling motivation to
keep them. To me, the company and the products were too new. Also the SFS-80 had been
reviwed by many trade magazines that mine would add little incremental value.
What has changed? For one, the model is no longer current and as such can be had for a reasonably attractive price. This changes its value proposition from whence it first emerged. Let me explain. When it was first unveiled, it was offered at $2750 and positioned as a rival of the best stereo amps available at that time, like the ARC Classic 60. Now it can be had for about half that amount, yet its performance remains undiminished.
What is there to like about the SFS-80? In my humble opinion, it is its self- effacement and quiet competence. It does not particularly call attention to itself. For example, when listening to the ARC Classic 60, I had noted at the time from some of my notes that it's ability to present the grandeur and scale of music was breathtaking. At the same time, the Classic 60 also had a leanness in the top end, one that is akin to the bite of a transistor amp, an artifact of its solid state input circuitry, I suspect. The SFS-80 on the other hand possessed no such trait. When listening to the ARC D-76, one immediately knows that this is a tube amp. The rotundness of the notes is quickly recognizable, including the occasional bass softness. On the other hand, the SFS-80 sound is cleaner, more precise and incisive at both the top and bottom end. The tube midrange magic remains. No, it does not have the quickness and impeccable speaker control of the Classe DR-9 nor its ability to establish a solid bottom foundation. But for a tube amp, it is not bad. In fact, it is better than all the tube amps I have had, the ARC Classic 60 excepted.
Lately, I have been revisiting classical music, especially the old pieces that I had started out with when I first got involved with audio. Mussorgsky's Pictures at an Exhibition (Deutsche Grammophon 428-785-2 GH) is so bold and powerful in both concept and rendition. Originally scored for piano, this orchestral version by Ravel (the most well known) is ideal for evaluating the mettle of audio systems and at the same time experiencing musical redemption. The ending is so emotionally charged, colorful and uplifting. The SFS-80 portrayed the various musical pictures within the gallery--their details, playfulness, misery, whining, and splendor.
Another collection of pieces that I continue to be fond of are the 21 Hungarian Dances for piano duet by Johannes Brahms (Philips 416 459-2). They are such delightful melodies with a wealth of unusual tone colors and flowing melodies. Despite, their age, they continue to remain fresh, beautifully earthy, and truthful. From the first piano notes of No.1 in G minor, one immediately senses that the SFS-80 is a special amp. It captures the woody reverberation, acceleration and deceleration, texture and content that it sometimes feels uncanny.
The SFS-80 casts a more dynamic presentation than the ARC D-76. It's soundstage is however a tad less spacious on the sides and deeper in the middle, hence the instruments seem to emanate from a deeper space. The Classe DR-9 outperforms the SFS-80 in terms of soundstaging and dynamism. To me, it's no surprise because these are the hallmarks of the DR-9.
Conclusion
After having looked at the Sonic Frontiers SFS-80 more closely, I have come to conclude
that it is one of the most underestimated amps in the high end used equipment market. It
is truly musical as tube amps within its hierarchy go. It can use different output tubes
from EL34s, 6550s to KT90s. Its construction and parts quality are first rate thus
assuring long term trouble free ownership, aside from the usual need to periodically
replace tubes. The output tubes can be biased easily via the front panel bias meter
and externally accessible adjustment controls. This is an amp for serious music lovers with
financial smarts.
I hope the SFS-80's resale price continues to remain affordably attractive. This is an amp to enjoy for the next two or so decades. I rate this amp four out of a maximum five clefs. So what are you waiting for?
by Rome Castellanes
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