My 404 should be here anytime now via UPS, but the one I picked up on ebay didn't come with the power supply.

Can somebody look at their power supply real quick and tell me the volts and mAs?

It should say something like:
Out: 9v 300mA

that is what I need to know. I am going to have to go to radioshack and get one to use, but I need to get the right thing. From looking at the specs in the manual I am thinking its going to be 9v 300mA

9v 300mA is correct

the weird part is the actual psu doesn't have the mA on it anywhere. luckily the back of the manual had it all in there.

yes, but is the ring or the tip positive? that's what the radio shack boys will axe you...

it looks to me like the tip is negative.

edit: yeah i've found a few online retailers of the roland PSB-1U that have the specs listed as polarity plus outside, so its negative tip.

i've got my 404 now and a power supply from radio shack and im loving this thing already.

Absolutely awesome. Seriously.

you know this is prolly a little late, but my power supply actually says 9V 2.0A. the extra isn't hurting it, but just to be precise...

yeah in the back of the manual under specs it lists the current draw as 300mA.

i think the roland PSB-1U or whatever the official power supply is, is 2A just because roland uses that as the official power supply for a lot of their 9V products. i know when i was googling the PSB-1U or whatever i kept seeing it listed on sites that sold it as replacement power supply for this or that, or some other thing. all kinds of roland product numbers i didn't recognize.

Here is a pic of the Roland PSB-1U for reference.

Polarity is most important to pay attention to as it can damage things unlike low/high mA which is far less likely to damage things. I wish I would have known that years ago would have saved me killing a thing or 2.

I am using a 9v DC 300mA center pin neg adapter right now for my 404 works great.

So I noticed a hum in my new setup- and humming/hiss related to how many buttons were lit up etc. My new 555 did not come with correct power supply so I used the 404SX one which is same as what ships with the 555 and I used an older 9v 300mA adapter on the 404. Tested w batteries, hum was reduced, tested with a 500mA power supply and the hum was even less, then with orig power supply and hum is almost entirely gone. Not sure if it is the supply or the increased mA but I would suspect the mA.

Something to be aware of. Even just a little hum over stacking tracks in a mix will muddy things up. Good place for a hi pass filter.

C

Ya, I used a Sampletrak 9v 300ma power supply for a while on my 404. I definitely noticed the hum when the pads flashed or the BPM light pulsed. Got it taken care of now with a psb-1u from my Roland mc307. The hum wasn't bad, just kinda annoying.