From: David_L._Snyder.wbst102a@xerox.com
Newsgroups: rec.audio.high-end
Subject: Re: Sonic Frontiers, VTL Amps
Date: Fri, 9 Oct 1992 12:39:31 PDT
Organization: University of Wisconsin - Milwaukee
NNTP-Posting-Host: 129.89.7.4
Originator: tjk@csd4.csd.uwm.edu

<steve@helix.nih.gov> recently wrote:

>I've purchased a Sonic Frontiers SFS-80 amp "on approval" and would like
>to hear from anyone else who is familiar with this amp.

I've actually just ordered a Sonic Frontiers SFS-40 amp ($1600) to replace a
very old Dynaco solid state amp (ST150).  I have smallish KEF Reference
speakers and an old Dynaco PAT-5 preamp that I'm replacing when I can afford
to.

I was originally interested in the Sonic Frontiers SFL-1 preamp ($1400) which
has been *very* favorably reviewed in Stereophile (most recent) and slightly
less favorable received in TAS (June).  The preamp I had on loan had some nice
qualities; very dynamically alive even at low volume levels, low noise levels,
reasonably smooth, great construction and parts quality, etc.  It,
unfortunately, didn't have the Yugoslavian tube and was a tad "dry" sounding to
me, even through the Thiel 2.2's in the store (which are very nice).  It also
had a very serious distortion problem -- almost to the point of completely
breaking up on hard piano attacks-- with the volume above 12 o'clock.  No, I
didn't play it through my speakers at that level, but through headphones
connected directly to the output jacks.

When I returned the preamp to the store they claimed that the distortion I
heard was due to impedence mismatch.  Is this possible?  I know that my CD
changer  (Nak CD2) most certainly has only a trashy op amp driving the
headphone jack, but at the same volume level as through the preamp the exact
same source had no problem at all.  When I told the sales rep that I was
skeptical of the impedence story  (I've plugged my AKG headphones directly into
preamps plenty of times with no similar symptoms) he suggested that the rhodium
jacks on the SFL-1 were smaller than typical and that maybe the cables were
poorly connected causing the problem.  I don't think so!  I think it was the
tube.

Anyway, the sales rep *did* succeed in getting me to take the SFS-40 amp home,
albeit for only 1 night.  It was a tremendous improvement in sound, far more
than I thought it would be.  I had tried other amps before (Classe &
Counterpoint) and neither had the same combination of liveliness and liquid
smoothness.  My Mahler CD's sounded terrific, with the full force of the
orchestra well portrayed, as did sources with smaller numbers of instruments /
voices.  I dunno about thin sounding cellos; the opening of Mahler's 2nd
(Kaplan recording) was very rich as were my Yo-Yo Ma sources.  For me, the
harmonic richness of the sound more than compensated for other possible sins,
perhaps even blinding me to them.  (BTW, I've had my hearing tested and have
much more acute high freq. hearing (5khz & up) than below 1khz, and can still
hear up to almost 20khz which may partially explain my differing impressions.)
I thought the amp was pretty well balanced and exciting sounding, although my
Dyna amp has virtually *no* bass, so I may be biased in my view.  Only the
Quicksilver preamp I auditioned had as dramatic an impact (almost too much) of
the components I listened to at home (which also included AR LS1 (too flat),
Classe #4 (not bad), CJ-PV11 (a gooey dog, IMHO) and Counterpoint 3000 (noisy,
but ok phono)).  As with the SFL-1 preamp I thought construction and parts
quality of the amp was pretty good.

I think I'll be pretty happy with the SFS-40 and will try out the SFL-1 again
when the store gets the new Yugo tube in.  Sonic Frontiers is coming out with
an all tube phono amp that's supposed to be really good ($900).  The SFS-80 was
out of my price range so I didn't listen to it.  If you have the bucks, I hear
that the VAC 90's are a must have.  VTL is supposedly too "hard" and
analytical.  If you want I can dig up names of dealers advertising in TAS &
Stereophile that I've talked to who seem pretty well informed.

Good luck & let us know what you end up with!

-- 

Thomas Krueger                       UW-Milwaukee Engineering Electronics Shop
tjk@csd4.csd.uwm.edu                                         +1 (414) 229-5172
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