Ilford DD-X same as Kodak XTOL ?

In my effort to switch to all Ilford products, I am wondering if DD-X is the same as XTOL (I think it is) and I am looking for some opinions on how this dev works with their films.

Any favorite combos? Any advice?

I don't know if that ius true, what I recall is that DavidCarper (ex-Ilford tech support guy) explained once that DD-X was the old tried-and-true Ilford DD adapted for small tnak use with some extra activators.

I really like it with Delta 400 and 3200. it does and excellent job in old-style emulsions as well.

Clayton F76+ is very similar to it IMHO

I just Googled for "Ilford DDX MSDS" and found this PDF. According to the MSDS, DDX includes diethelyne glycol, hydroquinone, 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, diethylenetriamine pentaacetic acid, sodium tetraborate, boric acid, water, and potassium sulfite. This is quite different from XTOL, which contains sodium sulfite, diethylenediaminepentacetic acid, sodium metaborate, Dimezone S, sodium metabisulfite, and sodium ascorbate. Even if some of these long names are synonyms for the same things or are close relatives, DDX has hydroquinone but no sodium ascorbate or ascorbic acid. That said, I can't speak to the effects of these developers; for all I know, they might produce very similar negatives.

AFAIK, the closest commercial counterpart to XTOL, in terms of formulation, is Paterson's FX-50, which as I understand it is based on ascorbic acid (or sodium ascorbate) and phenidone (or Dimezone S), just like XTOL. I can't seem to find an MSDS for it, though.

Alternatively, you could mix your own developer. Several that are similar to XTOL in broad strokes are described online, such as Ryuji Suzuki's DS-10 and DS-12, Paul Lewis's Mytol, modified versions of Mytol and XTOL, Chris Patton's E76, and various Patrick Gainer formulations (PC-TEA seems popular; it's 9g of ascorbic acid and 0.25g of phenidone in enough triethanolamine (TEA) to make 100ml, heated to ~120C, and used at about 1:50 dilution; but I don't know of a Web site devoted to it).

srs5694 gives good advice. DD-X is a phenidone-hydroquinone developer (like many other liquid concentrates) whereas Xtol is a phenidone-ascorbate developer. I tried Paterson's FX-50 but was not impressed, and I too am of the opinion that the most reliable phenidone-ascorbate developers are home-brews. Ryuji's developers are good but may be a little more complex to mix up due to some unusual ingredients (added to improve the storage life). E76 worked well for me. I usually use Pat Gainer's developers, though -- specifically PC-Glycol (an earlier version of PC-TEA) -- a solution of phenidone and ascorbic acid in propylene glycol which is diluted with water containing sodium carbonate just before use. Works well, extremely reliable (my stock solution is over 1.5 years old, no sign of deterioration).

It seems to me that DD-X is closer to HC110. If you were to look up the MSDS for HC110, you might find functionally similar ingredients, especially the developing agents which are hydroquinone and a relative of phenidone. The ones with the longest names are probably to keep hard water from clouding the solution.