Looking for Altec Lansing 1689A preamplifier schematic

[pvision]

Altec Lansing 1689A preamplifier - 1U two-input mic preamp with tone controls

Looking for a schematic, also info on the transformer wiring so I can switch it to 220 Volts. There are three primaries and the manual states it is a 100 / 120 / 200 / 220 / 240 volt unit. The primaries terminate on two rows of push-in connections. I think the push-in connections work by linking adjacent connectors

Thanks!