On Fri, 22 Dec 2017 15:46:47 -0800 (PST), wrote:

snip

And they do! I bought the 4.5v AC to DC adapter from CPC: PW02731 from
the 'other' thread before I discovered the original failed unit was AC
to AC and so I plugged the lights into it on the 4.5v setting (they
wouldn't run at 3v).

snip

It's not hard to drop the half volt

Oooo ... two std rectifier diodes back to back in one output leg? ;-)

but if it works ok, great, don't worry.

But it doesn't does it and for how it's working (brighter), for how
long?

From my experience of these things, potentially 'overdriven' LEDs
don't tend to last that long?

Cheers, T i m