The Matter Fabricator uses too little energy and too much scrap, it's completely OP. In GregTech, it used to consume 8192 EU/t, 16, 666, 666 EU per UU-Matter and 33.3 scrap per UU-Matter but it used to use a percentage system so it can not consume this quantity of energy/scrap with the Matter Fabricator from TechReborn.
So, my suggestion is to consume 8192 EU/t and during 2048 ticks which means that the Matter Fabricator will consume 16, 777, 216 EU. And about scrap consumption, it should consume 1 scrap every 64 ticks so every 524 288 EU. So it consumes 32 scrap per UU-Matter. And the problem is that it should consume 27 time less scrapbox. So the best solution would just be to not accept scrapboxes or just consume 1 scrapbox per UU-Matter. But please do something because in its current state, the Matter Fabricator is completely OP.

Looking at the source, the energy per amp value isn't calculated correctly, in fact it isn't calculated at all...

For each 1 value of AMP you need to pull 1666 FE, so at line 122 of TileMatterFabricator you need to add something like;
int feAmpFct = amp * 1666;
and replace the 85 with said value;

int feAmpFct = amp * 1666;
if (amp != 0 && this.canUseEnergy(feAmpFct )) {
this.useEnergy(feAmpFct );
...

RF is currently broken as well however, skewing the numbers...
#1230

#1231

The scrap use is about right IMO, but each UUM needs only 1,600FE, obviously 4 zeros are missing somewhere...

Fixed with #1231