Thank you 'ufospls2' for the post with excellent photos and explanation to the original EF1000 and the now todays one we see advertised.I think he means the original EF1000 (which IIRC was never officially released) which was created for the HE1000. There is now the EF1000DAC, which is still powerful, but not as powerful an amp as the EF1000 amp, but also features the Hifiman Hymalaya DAC modules. Couple photos of the pre revision EF1000 are below, it was then changed and updated to be the Hifiman solution for the susvara.
Below is the EF1000DAC (which does 13.7w at 32ohms, vs the EF1000 amp which does 20w at 32ohms.)
Yes, the 'pure' EF1000 has a separate power supply to provide pure DC linear power to the main Unit.
The recently launched EF1000DAC doesn't have a separate power supply, and has a different pre and power amp to the EF1000 and not as powerful.
My thinking between the EF1000 and the EF1000DAC is if you are going to spend this kind of big money on a TOTL Headphone System based on the Susvara, I would buy the EF1000 knowing you have a top TOTL Amp specifically for the Susvara and then buy a TOTL DAC to feed it !