hifi engine

Akai 1721L schematic required please

I'm having a problem with a 1721L. Any recording made on this machine suffers with low playback levels on both channels and a fair amount of distortion. As it's equal on both channels and playback of tapes from other machines is fine, I suspect it's a fault in the equalisation circuit.
As this is such a fine machine in other respects I'd like to get this final problem fixed.
But blow me down, I can't find a schematic anywhere.

I'd be really grateful if some forum member could upload one.

Many thanks.