Hi dude:
I recommend you to buy a cheapest used server PSU (Power Supply Unit) that could supply power for up to two S1/S3 ASIC miners.
Like an example of refered server PSU:
-HP Z800 PSU
-IBM x3650 or 3655 (835Watts)
-Delta DPS-835AB
-Artesyn 7001138-Y000
Any server PSU must have at less ...