You cannot just substitute ascorbic acid for hydroquinone. As has been stated many times on APUG the resemblence between these two chemicals is only superficial. Xtol is probably the closest ascorbic acid analog for for D-76 after all the correct adjustments to the formula have been made. Search on APUG for the formula which has been posted on more than one occasion.
There is also the Haist modification to D-76 which eliminates the hydroquinone and increases the metol content slightly. It is referred to as D-76H and is used just like D-76. Note that the name uses a captal H since there is another completely different version of D-76 referred to as D-76h.
water (125°F) 750ml
sodium sulfite (anhydrous) 100g
borax (decahydrate) 2.0g
water to make 1 liter
The version above is used as a one shot either FS or 1+1.
this is kind of like split d23 ( dd23 ) or one version of it,
but mixed together ..
i had heard years ago that when mixed together it was pretty much like d76 ( or one of its variants )
thanks for posting this !