UK SNES Power Supply - AC Vs. DC

[DaveJ-UK]

I have several UK/PAL model SNES consoles and original Nintendo power supplies, all of which are rated 9V AC 1.3A.

On fleabay I see a lot of sellers selling replacement power supplies that are 9V DC 400mA. Surely that's not an appropriate replacement?

I understand that the console might not use anywhere near 1.3A but my understanding was that if you used an AC power supply with a DC device then it would probably work for a bit but it would damage it in the long term?

[NFG]

You cannot use an AC adaptor on a DC device, it'll smoke immediately.  You can, however, use a DC supply on an AC device.

As for the Amps, you can supply more than you need, but supplying less isn't a good idea.

I have a PAL SNES and I use a PC Engine adaptor on it without problem, via an adaptor (the connectors are different).  The PCE unit is 9V 650mA.

[DaveJ-UK]

Hi Lawrence, Thanks for your reply.

I don't mean to sound patronising but is that just in your experience, or is it based on any electronics theory?

I used an AC power supply with a Japanese SNES for a short while without realising (Japanese SNES is DC) and it didn't blow immediately - still works fine to this day.

[NFG]

I'd say you got lucky.  I plugged a US NES power supply into a Famicom and it released its magic smoke instantly.  Maybe it was age, maybe the SNES is more durable or designed to cope, but yeah. 

I suppose if you want to get scientific about it you can do it a few hundred more times on a dozen different SNES' and let us know the results. 

[l_oliveira]

Super Famicon has an protection diode. Obviously, Famicon has the 7805 chip going straight to the DC input connector (only thing before the connector is the main power switch...)

[DaveJ-UK]

OK, cool. Do you think 100 will be a good sample size? I'll start buying up all the SNES' on fleabay right away! 

[People?]

The AC is only necessary for the RF output to work. If you use a DC power supply, you cannot get a signal from there. You have to use an A/V or RGB cable instead. The very same applies to the PAL NES.

Using an AC power supply in a DC-only retro console will either blow a fuse (if there is one) or blow the voltage regulator. Possibly, if you're unlucky, more stuff will blow.