The 1977 Apt/Holman preamp is one of the most famous preamps of all time. That’s partly because it was created by Tomlinson Holman, founder of Lucasfilm THX, co-founder of Audyssey Labs, and now working on audio product development at Apple. And it’s partly because the Apt/Holman preamp is such a graceful work, almost like a piece of laboratory gear as envisioned by one of IKEA’s industrial designers.
I love the cool little pushbuttons, which have mechanical covers inside that reveal green and white status indicators. No mere stereo/mono switch would have done for future surround-sound pioneer Holman; instead, he gave the preamp a mode dial that adjusted from full L+R (essentially a mono center-channel signal) to normal stereo to full L-R (essentially the signal that would go to the surround speakers in a Dolby Pro Logic setup). Infrasonic and ultrasonic filters save your woofers and tweeters from damage. The internal phono preamp’s cartridge loading options — capacitance from 50 to 400 pF in five steps, resistance at 47 Kohms or 100 Kohms — give more flexibility and fine-tuning than most of the today’s super-high-end phono pres. Want the full story? Here’s a PDF of the original review from Sound+Vision’s predecessor, Stereo Review.