Introduced after the success of the modestly priced SFL-1 (1991) and its SFL-1 Signature version (1993), the SFL-2 got a “Class A” Stereophile Recommended Component.
Not that I did ever take magazines’ awards as gospel but the SFL-2 really was that good and designed by the original Sonic Frontiers team : Chris Johnson, John Sloan and Joe Curcio.
Spread over two chassis, the all-balanced operation is done by six 6922 Sovteks with 15 regulated power supplies (six discrete and nine IC-based), no NFb circuit and “ultra parts” sourced from the good people : 22 MIT caps, 28 Caddock and 8 Vishay resistors with Holco resistors, Solen p-s and shunt caps, plus Kimber sliver wiring, Kimber RCA and Neutrik silver-plated XLR terminals.
Also split-bobbin trafos, B+ and B- supplies with 280µF of Solen metallized polypropylene caps and a separate transformer / power supply for utility functions such as muting relays and LEDs.
And also single-ended and balanced DIRECT inputs which bypass everything but the mute and attenuator.
Last but not least, and most important, crucial even, the volume attenuator is a 46-position fixed resistance array – only the best so the SFL-2 could be that good.

Frequency response :20Hz…100Khz (± 0,5dB ; 100kOhm load)> 350Khz (-3dB)THD :< 0,1% (20Hz…20Khz ; 1V output)< 0,03% (typical ; 1Khz)Gain :22dB @ 1Khz (single-ended)28dB @ 1Khz (balanced)

Residual noise :120µV unweighted (balanced out ; volume @ 12 o’clock)-85dB @ 2V RMS outputIMD :< 0,05% @ 2V output< 0,03% @ 2V output (balanced)

Input impedance :50kOhm (single-ended)100kOhm (balanced)

Output impedance :160 Ohm @ 1Khz (single-ended)320 Ohm @ 1Khz (balanced)

Minimum recommended load :10kOhm

Output voltage :30V RMS max. (s-e ; 100kOhm / 100pF load)60V RMS max. (bal ; 10kOhm / 1000pF load)

Maximum input :2,5V RMS (volume fully clockwise)

Stereo separation :70dB @ 1Khz (single-ended)75dB @ 1Khz (balanced)

Tubes :8x 6922 (6DJ8 type)

PC :75VA (standby)135VA (max.)

Dimensions :48 x 11,5 x 33cm (each chassis)Weight :25kg.