Audio Research BL-2 Balanced Line Driver

Solid state 7 channel balanced line driver. Single ended inputs to balanced outputs with single ended record output.  Top of the line.

Audio Research BL2 is a selectable-input balanced line driver which allows you derive a balanced signal from up to five single-ended sources, plus built-in tape handling capability. Thanks to the BL2's high input impedance and low output impedance, your favorite sources will sound their absolute best when feeding a signal.

Here is what Bill Johnson had to say about it - excerpt from a stereophile interview: 
"Although I will say that, in recent years, we've been able to design good-sounding solid-state products—like the BL1 and BL2—that have only unity gain. We're using an IC chip with significant buffering both before and after it, and we've found that we can just about equal vacuum-tube sound with that, providing we stick with unity gain. The minute we try to have significant amplification with them, of course, the results are not as good. "