One rarely encounters a modern electronic product that embodies vacuum tube amplification as well as the D.W. Fearn VT-1 microphone preamplifier. It truly reflects an era long past when products were made one at a time by their designer. There are no semiconductors in the VT-1Us audio path. The sound is completely derived from the two 12AY7 dual triodes and two Jensen transformers (one for input; the other for output). Its beautiful, maroon front panel spans three rack spaces and is made from a robust, quarter-inch slab of aluminum.
At the beginning of the operator's manual, Mr. Fearn explains that the inspiration for the VT-1 came after listening to tapes recorded in 1968 at his first, home-brew studio. His 'mixer' was created from six, 40s-era RCA tube preamps found in the junk room of an old radio station. There was no EQ and no pan-pots, only left-center-right switches and rotary faders.
From my storefront in New York's East Village, I strung cables to the nearby First Street Cafe to record an avant-garde jazz trio. The group, Out of Order, consists of electric cello, traps, and a multitalented fellow who plays alto sax, flute, and trumpet.
Since I had but a single channel of VT-1, the opposite channel alternated between the Aphex Tubessence and the Rolls RP-220. The preamps were fed directly to a Fostex D-10 DAT recorder. The two AKG CK91 microphones (cardioid capsules on SE300B bodies) were placed about five feet in front of the cellist (situated between the other two instruments). Both mics were pointed straight ahead and spaced about three inches apart. A personally hand-crafted monitor box facilitated the task of separately auditioning each channel. The output was routed to both channels of an amplifier and monitored on both headphones or speakers.
During quiet passages, the first obvious difference among the three preamps was the Fearn's ability to capture the rumble of trucks as they barreled down Houston Street. More subtle was the wide-open space around the cello's lower extremities. Neither of the other two preamps tickled my rumble bone as much, but the subtleties became more obvious as the trio's dynamics shifted toward forte.
Channels were balanced during mezzo (moderate) passages, but percussive drum hits revealed the nuances of each device's transient capabilities. Peaks that nearly became 'overs' on one channel of the DAT's peak meters were 3 dB to 8 dB lower on the opposite channel. I repeatedly listened to each channel to compare the sound of the hits. Those differences were clearly audible, never bad, and subject to the taste of the listener and the appropriateness of the material.
On the bench, the Fearn VT-1 had the most headroom of the three preamps I tested. Asymmetrical clipping on the lower half of the waveform starts at +23 dBu. The upper half of the wave begins to soften beyond +25 dBu. The exact opposite occurs when the VT-1 is terminated with a 600 ohm resistor. The positive peak starts flattening out at +10 dBm, while the negative excursion gets pretty round by +15 dBm. The worst case signal-to-noise (S/N) ratio is 85 dB at maximum gain (more than 10 dB better than published). At minimum gain, the S/N is well in excess of 100 dB.
To reduce headroom and enjoy more of the tube's nonlinear qualities requires either lowering the input at the DAT, overdriving the input stage by not using the pad, or terminating the output with various resistors. (A switch disables the beautiful analog meter if you wish to overdrive the preamp without damaging the movement.)
It is interesting to note that, when driving a 600-ohm load, the VT-1 behaves much like the older, Class A Neve modules. Both react like limiters to short bursts of signal by letting most of the peaks through, then gradually settling into the old soft clip. Incidentally, the most symmetrical softening occurred when a 6 kohm terminating resistor was used.
D.W. Fearn provides a 5-year limited warranty and will provide two, selected 12AY7s for the preamp and less critical output stages for $50. This is a good deal considering that the alternative is to buy several tubes in order to select a chosen few. If you are wondering how to justify the $2000 price, keep in mind that this unit is extremely robust and is made from the highest quality components, including fine metal work inside and out. The audio circuitry is wired point-to-point (just like in ye olde days) and the power supply is semiconductor regulated. This pure vacuum tube product is your time machine to the past. Like our memories, the Fearn VT-1 is better than being there. Eddie Ciletti