Sold a MK2 Tonebender clone (PNP, but with a TC1044 inverter) fella is having an issue with it that's really confusing me. Made quite a lot of pedals this way fwiw (probably over a hundred by now) and this was tested and working.
With a DC adaptor, LED lights up. No sound when pedal is turned on. With an external 9V battery adapter, No LED, but very low (far below unity) output.
At first I'm thinking I have an idea what's happened. My first theory: DC adaptor isn't regulated and the inverter fried (off the top of my head it's only rated for 10 or 11V) and the battery adapter he's using is the opposite polarity to the plug.
That's been shot down as the fella insists both the battery and the DC adaptor plugs are the same polarity. Which has left me completely baffled.
I've sent him some more TC1044 to try, but if just curious if anyone might have any other theories as to what might explain this, if both power sources he's using are indeed the same polarity.