The Mod Squad Phono Drive phono preamplifier
One such tinkerer is The Mod Squad's Steve McCormack. I remember being awed the first time I saw the Squad's stapled catalog, way back in 1982 or '83: there was page after page of detailed descriptions of how Steve could make Ittok tonearms, or Rogers LS3/5A loudspeakers, or Quad 405 amplifiers, or Spatial Coherence preamplifiers, or Meridian CD players sound better than their original designers had thought possibleor necessary. Who was this guy? I pondered from across the ocean.
A Connecticut Yankee, Steve worked at retail for Los Angeles dealer Jonas Miller, back when high-end meant Quatre and Mitch Cotter, Electro Research, and the various incarnations of the Audio Research SP3. He then acquired valuable experience at the sharp end of the reproduction chain by working as a recording engineer for M&K Realtime. After spending time on the road for Oracle, he and Joyce Dudney Fleming set up the twin-headed operation of The Mod Squad and Music By The Sea, the first to formalize his modifications and to offer a forum for his design ideas, the second to create a dealership working along the lines he and Joyce thought necessary for a high-end operation.
Then came Tiptoes, an elegantand commercially successfulidea that set The Mod Squad on a different course. Joined these days by circuit-design engineer Jerry Boncer, Steve has steered the Squad upward and away from the art of modificationthe modifications are no more, the shop being closed last July. The Mod Squad has evolved into a bonafide manufacturer of American High-End components; it can now stand on its own feet.
The Mod Squad Phono Drive: $1295
When I first saw The Mod Squad Line Drive prototype, back at the beginning of 1986, I had understood from Steve McCormack that a cartridge preamplifier/equalizer would soon follow, being a basic "black box" that would fit inside the control unit to transform one of its inputs to phono. After working on various IC or discrete-bipolar designs, however, Steve realized that in order to get the sonic quality he felt to be essential, he would have to revise the whole concept, circuitry and all.
The result is the Phono Drive, a separate component that externally appears identical to the Line Drive, with its black-anodized front panel having four control knobs in identical positions. It too has an aluminum chassis, but this time damping material has been applied to the underside of the top plate to eliminate the last trace of microphony. Reducing the effects of vibration on the circuit has been a major priority for Steve, as has been trying to ensure that the circuit sees a stable thermal environment. With the same circuit in the open, he explained to me, as you wave your hand over it you can see noise and distortion levels change as the components are buffeted by the air currents. The Phono Drive chassis, which has no ventilating slots, is therefore used as a longtime-constant heatsink for all the major power-dissipating parts; once it has reached thermal equilibrium, it keeps the circuitry at a constant temperature. In addition, the most thermally sensitive componentsthe matched transistor pairs for the MC stage and their voltage-regulator current sourceare enclosed in blue plastic boxes to act as little thermally stable "ovens."
The Phono Drive takes around two hours to come up to temperature, but attains its best sound after two days of warmup. There is no on/off switch; the unit is obviously intended to be left on all the time. Though fitted with a three-pin mains plug, the grounding pin is not connected, only being used to ensure correct polarity.
Looking inside the Phono Drive reveals one large printed circuit board, finished in black with tracks on both sides, that carries the power supply and both phono-section and line-section circuitry. A small pcb carries the Noble balance and volume controls for the line stage, these connected to the main board with Teflon-sleeved solid-core Wonder Wire. As this is directional, The Mod Squad takes care that its use is consistent with the way it comes from the drum, always following the signal flow. Components are laid out in a "Manhattan" configuration; ie, resistors and capacitors are oriented in two directions, at 90° to each other.
The component quality is excellent. WIMA polystyrene and polycarbonate caps are much in evidence, while all the resistors appear to be close-tolerance metal-films (with the exception of one large, 1W dissipation type associated with the MC stage power supply). As with the Deluxe Line Drive, Wonder Solder is used throughout.