The original D'Mars had a 5879 OD. I used a D'Lator with it and it sounded great! However, I got lazy about hooking up the D'Lator and decided to put the active FX on board and removed the 5879 in the OD. And I liked how that worked out. (all done with original Hoffman style D'Mars turret board)
Long story short, I slowly tweaked my original D'Mars for almost two years. Some of that was prompted by changing speakers or effects pedals. Then I sold it and rebuilt it with neater wiring and added a 5879 back into the OD section.
So, this one has both a 5879 and active FX on board. I'm really happy with the tone. The original (modded) D'Mars clean channel turned out better then this one has & is more musically sweet, IMO. However, the 5879 OD channel has something of a "vowel" tone with the 5879 in the OD section & perhaps has a little more sustain. More then not, overall, this one sounds much like the original modded one I just sold. That informs me that it's pretty easy to reproduce the tone in a new build. The layout is different and the wiring is slightly neater so I don't regret building it.
I like Hoffman style turret boards. They are very quiet. However, because I wasn't sure how the 5879 OD with FX on board would sound, I used a parallel turret board in case I ended up switching stuff out (which is easier with paralleled turrets). Now that it's a proven build, it could be done with Hoffman style board.
Over the two years, I've learned that the D'Mars benefits from tweaking depending on the speaker that you are using and even the effects pedal you are using. This turned out very quiet at idle like the original one did. It has the best "quiet at idle per volume/loudness" factor of any amp I've had.
with respect, Tubenit