Oh man every time I think I’m getting this problem beat you guys throw some reality at me 
Yes, the adaptors are AC so no problems with polarity…my flatmate (an apprentice electrician) suggested that our AC current may not be equal (sine wave?) but biased, so I erred on the side of caution. But I gave up caring (not a good position to be coming from when trying to resolve a problem!) and plugged in the 1A adaptor. No problem as far as damage to the preamp but no resolution to the phantom power being at 45V either.
As alluded to by some, the phantom power was not loaded (with the mic connected) when I checked the voltage. However, I’d only expect the voltage to drop further with loading? The reason I keep harping on about the voltage being at 45V is this from the Rode NT1-A mic manual; "Some Phantom Power supplies do not supply the voltage at which they are rated. If the required voltage is NOT supplied, the dynamic range and general performance of the microphone will be reduced."
Thanks for all your suggestions and help. I gotta say though, my amateur electrical egineer days are over (grrr…frustration) and I’m taking this puppy to a pro.
Cheers
Gramps
One thing more for you to do. Try the unit with a dynamic microphone, SM57, 58 or similiar. How does it sound?
Hey varakeef,
Yeah, you’re right that would be a pretty quick and easy test. I sold my old dynamic mic with my old tascam 4 track so don’t have one on hand 
Maybe I can track one down some where though. Worth a crack.
See ya
Gramps
Does the Rode doc say what the required phantom voltage is?
48V is a typical output, but some devices only put out 12V and work with lots of mikes. The purpose of the phantom power is just to put a charge on a device really, the mike doesn’t actually draw any meaningful level of current. (For this reason, plugging the mike in isn’t likely to change the voltage – but still it’s an important test to do.)
Bad cable is definitely a high likelihood, just based on experience. I’ve seen many more bad cables than bad mikes or preamps. Measuring the resistance alone might not be a sufficient test, either. Better to try a different cable, one that’s known to work.
Hi Learjeff,
The Rode manual says, “The NT1-A requires P48Voults or P24Volts Phantom Power”. I should have included this with the other quote from the manual to make it clearer. I’ve taken the preamp to a technician now so hopefully soon I’ll have the verdict. Cheers for all your help.
Gramps