Thanks everybody!
...i first made sure, the polarity was right. "Sure thing", like harmony in nature; i found the thread about right/wrong polarity in pedals. My adjustable power supply is now set to the same polarity as the rest of my supplies (and my 9V batteries & connectors)-
Just tried it with the Joyo Ultimate Drive, i got from a USA, SDUGF friend as a gift (Thank you very much man, sorry I can't remember your name right now!)
...not because it was a cheap pedal- it was a gift! But also, yoyo is a great brand, and it didn't come with a supply.
ANYWAYS!
On 7.5 volts it is actually LOUDER! In amplification, than before,. It has less distortion, but seems to hit my power tubes harder, at a lower volume.
"It's just like the fuzz pedal I wish I had"
Great success!
I'm still with caution with the rest of my gear for now. It's Friday , and I'm just having a beer to relax...
Rock on guys!

\m/ ♪
-E