Does anyone have a internal picture or schematic of the UA 508 EQ?
It is a passive EQ that can be connected across the feedback loop of the 1108 (instead of the 8.2k resistor)
"Envelopmental equalization is achieved by electronically enclosing an external equalizer within an active feedback loop of the amplifier. Used with the UA 508 eq the 1108 provides flexible eq with 0 gain loss. High frequency equalization (switch selectable at 5 or 10 kHz) can be set at 0, +3dB, +6dB, or +9dB boost or -3dB or -6dB rolloff. Low frequency equalization can be set at 0dB, +3dB, +6dB, +9dB boost or -3dB, -6dB rolloff at 50 Hz. "