Boss ACA power

UnclePsychosis

Picked up an older CE-2 from the classifieds here. 

It's one of the ones that needs the ACA PSU. 

Now the internet reckons it's safe to run this using a modern 9V supply so long as it's daisy chained. My pedals are all daisy chained so this isn't a problem---but are there any downsides or dangers to doing this? 

Also, anyone got a link to the blank replacement base plates for boss? Don't really wanna stick velcro on a pedal that's survived this long. 

Winny_Pooh

Theoretically you cant damage it on 9v but the leds often dont power up. Maybe time to get a voodoo labs pedal power if you like the ce-2, they have switchable 12v outlets.

jamiexsilver

My HM2 was the same, I got a mate to mod it so it works with any power supply. It's a pretty simple thing to do by all accounts.

UnclePsychosis

Not keen on spending a hundred notes on a fancy PSU when I only ever play at home to be honest. 

ICBM

If you're running it on a daisy chain it will work perfectly and safely with a standard 9V supply - all that happens is that the extra resistor and diode are bypassed by the common ground connection.

If you want to run it from an isolated-outlet supply as many modern ones are, you just need to bypass these two components inside the pedal - you can often do it with a blob of solder, or with a small piece of wire if it won't reach. You do not need to remove the components - in fact in my opinion you shouldn't, it's more work and prevents it easily being put back to stock if it ever matters to anyone.

An unmodified one will also run perfectly from an isolated 12V supply, since that's really all the ACA is.

UnclePsychosis

Thanks @icbm that's good to know. I'll maybe bypass the ACA at some point if I can be bothered. 

Why did Boss bother with it in the first place? It doesn't seem like the world's best design... 

ICBM

UnclePsychosis said:

Thanks @icbm that's good to know. I'll maybe bypass the ACA at some point if I can be bothered. 

Why did Boss bother with it in the first place? It doesn't seem like the world's best design... 

I think it was to make the pedals more robust against poorly regulated power supplies, which were fairly common back then. A totally unregulated 9V supply can have an unloaded voltage as high as 13 to 14V, and since pedals draw very little current then it has to be assumed they might see that much from a '9V' supply, which might not be good for the pedal (although most will actually take it).

So they essentially put a basic regulator in the pedal, and made their own power supply sort of 'unregulated' as well. That seems to be a bit backwards, I know!