I just bought a 555 on ebay without a power cord, and the only info I have been able to find so far on the matter is that it's a 9v supply, so I'm wondering if it is compatible with standard guitar pedal power supplies or uses a proprietary connection? I'm still waiting for the thing to get here so I want to get the right supply as soon as I can.

you can try a cord that dishes out 9v of power. sounds pretty weird for the 555 to use that little power. might wanna just order the right cord or you'd be lookin forever if your pedal cables dont work. i remember i used a power pack from a sharpner to go with this cd player guitar trainer thingee and it worked. another thing you might bump into is if the cord actually fits into the 555 hole. might say 9v and be a different size, ive bumped into that too.

Before you go pluggin things in...

Here's what you needa know:

1. make sure it's 9V DC (not 9V AC)
2. make sure the tip / ring has the right polarity... power supply will either be tip negative, or tip positive..

The SP-404 is tip negative, so i assume the 555 is as well...

you will hopefully see a symbol on the power supply somewhere that looks like this:

(+) ----C o-------- (-)

The 'o' is actually meant to be inside the 'C'.. the line connected to the 'o' is the 'tip' and the line connected to the 'C' is the ring.. So you see in the diagram it has negative tip.

Most devices are tip negative, but its good to be aware..

Finally, you want the max current output to be *at least* 500mA, although closer to 1A would be better since I think that's what the official roland supply is rated for. (1000mA = 1A) )

The thing with current is more than the required amount is better than less - the device will only draw as much as it needs, but if it cant get enough it will have problems functioning

So, the back of the 555 only says "USE ROLAND PSB-1U ADAPTOR ONLY" of course because Roland would rather you buy their expensive ish! The adaptor itself has the actually specs on it though, which are:

INPUT: 100-240V-,0.4A,
50-60Hz (+)--(o--(-)
OUTPUT: +9.0V---2A 18W MAX

The Roland adaptor is $29.95 new, but you could pick up a universal AC/DC adaptor for about half that which has various tips (hopefully one of them will fit). Hope that helps!

Thanks for the info; I should have specified that the reason I am asking is because I have a daisy chain that I could use with it as long as the tip is the same size. I didn't want to go spend 30 bucks on a new power supply if I didn't need it (I could buy a whole new One Spot supply and daisy chain for that much) . I guess I'll try it with my current setup and see how that goes.

Just make sure you use a PS with enough power. The one that goes with SP 555 is 9V 2A. So you look for one that is capable close to 2A (amps).
SP 555's book say that current draw is 800mA (0.8A) so it should be fine with 9V 1000mA PS but for how long.

Forever. There's no reason why it shouldn't If it's capable of 1A, it'll do 0.8A with ease.

Just got my 555 in the mail today, and now I can confirm that it works with my One Spot power supply; now I have the ultimate pedal board for my guitar!

i like to use my SP as a guitar pedal