Hello Prof, good to see you.
The Original Series was indeed sequential, 01, 02, 03, 04 with advances marked in small letters. The 01(01a, 01b) was Thiel's first marketed product. There are some still out there and Rob says they have a loyal following. As a seminal product, the 01 illustrates Jim's fundamental values. They were small, inexpensive, very sensitive, flat with unbelievably effective bass. Deficiencies included refinement, delicacy, coherence - the audiophile virtues.
We sold about 1000 pairs between 1975 and 1983. The breakout success of the CS3 in 1983 (actually a 4th generation 03) changed our dealer profile and overwhelmed our production capacity. The 01b was dropped for those reasons - it was still selling strongly.
The 01 was a 10" x 1.5" two way with equalized bass and 3rd order slopes. Its veneered 0.85 cubic foot enclosure had a foam grille, and the woofer a foam surround, both common at the time and prone to ultraviolet deterioration. The on-axis response was flat (+/- 1.5db) from 30 to 18kHz in an enclosure only 13% larger than the 02. Its woofer was Eminence's first custom driver (model 10101).
Within easy access 70 miles down the road, they supported our customization of their bomb-proof musical instrument workhorse which they built under their own name and for Peavey at a clip of thousands per day! The tweeter was by Long Engineering and sported a mylar dome mounted in a phenolic ring for minimal diffraction.
The equalizer was the 01's claim to fame. Unlike Bose, which pushed small drivers way past their range of efficiency, Jim's EQ boosted 10dB (as the 03 - CS3.5) to stay below the power required for midrange peaks. The equalizer was optional, accounting for $75 of the $350 retail price.
Being our inaugural start-up product, our quantities were too small for cost-effective purchase of anything except drivers which we picked up from the factories in our 1958 Edsel station wagon. We wound our coils on 'George', our shop-made spinner and etched and drilled the EQ printed circuit boards. Of course we made every aspect of our cabinets including our veneer faces - all in the original farmhouse.
Our first CES was spring 1977 where we showed the 01 and 02 to an enthusiastic market including the German distributor of DCM Time Windows. Strong German reviews and market brought interest from high quality east-coast USA dealers. And the rest is history.
We were naive and unexposed to any audiophile considerations or market. The 01 was designed as an all-purpose speaker that did well what Jim considered the necessary virtues. That Eminence 10101 woofer persisted through the 03, 03a, 03b sequence and is still available through Rob. I bet you'd like them if you can find a pair. Thanks for asking.