It sounds like your 18v adapter may be faulty, if it induces noise into your amp through the AC mains even without the UV-1 plugged in. My Dunlop 18v supply was too noisy for my liking, but I don't think it did that. It was a small but heavy analog one.clapointe wrote:I'm pretty sure it's the Dunlop 18vt adapter ! If I turn on my amp and ONLY plug in the 18vt apater I can hear the added background noise !lolbou wrote:But only the CMOS parts get the 18VDC from the adapter. The audio in the circuit gets its power from the 15V regulator inside.
And A+ is kinda filtered with the RC network, isn't it?
I have to test another 18V to hear...
Yours isn't a switch-mode adapter is it? If it is, it will be very small and light weight.
I will check my old 1995 UV-1 again to see if it has the filter and regulator network inside, like lolbou's diagram.
It certainly should provide good filtering and regulation for the IC's and transistors in the signal circuit if it's inside the box.