Input/outputs 5 & 6 may be configured with plug-in boards (e.g., 523, 522, 526, 528) for various types of inputs or outputs.
In practice, most people never use these. The NA 528 adjustable line-level boards do not perform as well as the straight wire links (on current 52s) as they feature a simple RC filter (intended, in its day, to attenuate the over-emphasized tonal balance of early Compact Disc players, IIRC), which will affect the sound. (In other words, I wouldn't plug a CDS II into INPUT 5 through one of these boards.)
The NAC 112 and NAIT 5 are the only current products to feature adjustable input level on each input, though this is really a "programmed" nominal (microprocessor-scaled) volume setting (the NAIT 5 and 112 use a microprocessor-controlled resistor-ladder arrangement, not a VCA chip). In the case of the 92R / 102 / 82 / 52, the volume adjustment is made in the analog domain, using a motor-driven potentiometer ("total-recall" automation of which presents another challenge).
Dave Dever, NANA
[This message was edited by David Dever on WEDNESDAY 28 November 2001 at 16:14.]
