Sonic Frontiers SFC-1

From a time when "affordable tube amp" didn't necessarily outline a chinese provenance, the SFC-1 was Sonic Frontiers' first entry-level line preamplifier, designed like all of SF's production by Joe Curcio.

The absence of a phono input made for most of the savings but the rest was built like its separates and with the same kind of "ultra" parts : Tiffany i/o plugs, Edison-Price speaker terminals, Cardas wiring, ALPS pots, Holco, Wima, Vishay, Solen caps & resistors, plus Golden Aero tubes.

The three transformers are grain-oriented silicon steel home-made designs, with the output two having a fixed 6 Ohm tap ; polypropylene shunt caps, right-angle and "en l'air" wiring finish the seriously hand-made picture.

The preamp part is based on regulated 12AU7A and 12AT7A triodes direct coupled to a differential phase splitter/driver stage ; output tubes are two mil-spec and matched EL34L.
The feedback loop is kept at a low 11dB level and screen and bias supplies are regulated as well, of course, naturally.

One input source can be privileged by being plugged into Direct terminals : this Direct input bypasses all front-panel functions and selectors except muting and volume.

The back-plate has a meter and two pots for checking/biasing the tubes with two max. readings : "40" for the pre-installed tubes (and longest lifetime) and "50" if swapping the latter for 6550, KT88, KT90 or KT90a tubes.

Wonderful music is made by the SFC-1.


The owner's manual can still be downloaded off Anthem's website : here.