Can Merlin400 only make CBD oil, or will it make full-spectrum THC oil too ?

The short answer is that Merlin400 will extract all types of cannabis and hemp. So yes, you can make both CBD- THC- and fullspectrum-olis, depending on the herbs you use.

Merlin400 performs an alcohol extraction, meaning that potentially everything that dissolves in alcohol will be extracted from the herbs. You don’t want everything, though – wax, chlorophylls, lipids etc reduces the potency and quality of your extract.
We have done a lot of research and fine-tuned the extraction parameters in Merlin400, to get the compounds you want (mainly cannabinoids and terpenes) and avoid the rest.
The composition and amount of cannabinoids (CBD, THC, CBG, CBN etc.) in different herbs vary a lot. Industrial hemp can contain from 1-6%, mainly CBD, while cannabis and skunk can contain up to 20% cannabinoids, of many different compositions.
Merlin400 can make a usefull extract from herbs with as low as 1,5% cannabinoids, giving you an extract with 40-60% cannabinoids. With high-potency herbs your extract can reach 65-70% cannabinoids.