I can give you my personal opinion on the two and the pro's and cons that ive encountered on both machines.

404:

- More pads, storage, effects as seen in the specs
- Stronger build
- Much faster processing time. It takes much longer to delete/record or process a recorded pattern on the 303...
- sub pad
- better knobs
- inbuilt mic
- battery powered
- compact flash!
- Time stretching and Vinyl sim dont seem nearly as harsh as the 303's
- cleaner sound with sharper and rounder hi's

303:

- Pads are really much better. and for those who own a 404, its like the sub pad -but a tad bit softer and more responsive. I can actually record a sequence without quantize on this machine and it will actually play back what i played!

- Looks and feels much better and is smaller and lighter. This is more personal preferance, but basically i feel more comfortable with the 303.

- Sound is incredible. At first i thought it was a myth, but the converters seem to cut the hi's and smooth the mid frequencies and it sounds pretty warm. Although keep in mind that it is extremely subtle and wont instantly "grimy" up a drum hit or whatever.

- Sequencer is more fun in real time. This is a personal preference thing again but i like doing my songs in real time and not on a grid and i love how you can flick to a sequence and cuts the samples. Definately quicker and more fun for me, but i can understand how that might be the exact opposite for some who really organizes theres songs well..



So yeah, both machines have there advantages and disadvantages, but what works best than either the 303 or 404 is both of them together! Seriously this is a mean combination and recording through to sp effects at the same time is sick!

interesting - thanks for taking the time to actually write this... I will see how my 404 reacts to pavement and get a 303...

Hey I own both, too! Great post. I never noticed that the sub pad on the 404 was more like the 303's sample pads, but you're definitely right. I wonder if the 404 sample pads will get softer after a couple years of abuse?

One thing I really like about the 404 over the 303 is that some key effects now have a "Balance" parameter instead of an "Effect Level" parameter. I like being able to cut out the dry signal completely, though I imagine some might have preferred it the other way.

Oh, and another nice thing: being able to instantly access all the effects at the press of, well... 2 or 3 buttons, instead of scrolling through the effects.

I was really hoping they would fix the placement of some of the operational buttons, so they weren't so close to buttons that would make the 404 effectively shut down. I hate it when I'm playing live and reaching for the Remain button (to assign effects) and nudge the record button enough to make everything stop and go into record mode.

Oh and man I wish you could make the Delay effect hold on to the feedback and shift it between sixteenths, eighths, etc, like some of the old boss delay pedals!

The SP-555 has both better placement of those knobs and so on and a Delay effect with the possibility of shifting between sixteenths, eights and so on. You can change feedback level, balance and the timing...

Ooh! I'm so jealous!

Oh well, I guess the 555 wouldn't fit in my rig, anyway. But, still, I love that effect.