"Still waiting, but maybe they'll arrive today. Atmasphere. let me ask you a question. If you could design a passive preamp, choose an appropriate source with just the right output impedance, select the cabling to be used (for appropriate electrical properties- and lenght)and they were feeding one of your OTLs or some other quality 100KOhm load - that is you could optimze the variables that determine successful versus unsuccessful implementation of the passive approach - could you conceive that a passive, minalmist approach might work better, sound better than an active, any active preamplifier. I would accept that the passive might not be as flexible, be more fussy, and may be less universally marketable."
Here's the problem that passives are up against (if done my way). 'My way' is to eliminate the interconnect cable as a sonic variable so that any cable will work as well as any other (right now you have to go balanced to do that BTW).
Anyway, to achieve the above for me would mean a very low resistance passive system- probably about 100 ohm control would do the job. This is a challenging impedance for a CD player to drive with low distortion and enough voltage to drive the power amp. Please keep in mind that I am expecting the system to be immune to the effects of the cable. You are not going to get this if the value of the passive is much higher than that. IOW, its impractical with current CD players and phono sections.