Companion of the P-1.
Uses two 18bit resolution Burr Brown PCM64P and 4x oversampling with Teac's staple ZD-II scheme.
Unlike the Sony combo, clocking between the drive and D-1 is uni-directional ; there is however a double PLL loop. Mos-FETs tackle the analogue signal cicuits.
Inputs consist of three 75 Ohm coaxial and a TOS optical ; a coaxial digital output is provided. Analogue outputs are fixed or variable (RCA) and a pair of fixed XLRs in balanced mode.
The inputs are feather-selected by touching the fake drawer ; phase inversion and muting have their own pads.
Three switches at the back allow to sum the two stereo channels in mono (yes !) and filter the L and R outputs separately (low-pass ?). An added 8-pin terminal is labeled "ext. control" - I don't what this allows...
Direct competitors in 1987 was the Sony DAS-R1 and Philips LHH1002 - Stereo Sound even made a "match" comparing the three combos in 1988 !
Of the three, only the Sony DAS-R1 and P-1 / D-1 got a "Golden Sound Award".
Sales-wise, however, only the Sony combo ruled, worldwide, and still does so - souvenirs-wise.
Sound-wise, there is no match : the Sony and Philips still rule while very few fight to get a D-1...