Connect MPC One to SP404 Mk2 for FX?

Hi. I want to connect my MPC One to my SP404 Mk2, so that I can use the SP's effects. It's common sense I guess (but I also used this video). The dude in the vid has a Live 2 though...but anyway.

I have 2 cables from the MPC One's master outs, going into the SP's Line ins. Then another 2 cables going from the SP's line outs, into the MPC's line ins. I fire up my MPC as well as the SP, I set the SP to "Ext Source", play my beat, but the SP effects does not seem to affect the sound at all. The music plays but the SP is essentially not working.

What am I missing?

You have made a feedback loop. To do what you want really requires more than two outputs, so you'd need to invest in a USB sound card or something similar if you wanted to hook things up that way.

The problem is, that you can go output of one into the input of the other... and then the output of the other out to headphones or speakers, but you cannot really just go out to in of one device, and then in to out as you described. When you do this, the audio signal will start, but then will be passed on and sent to the next device, and so on, until it makes a blaring tone.

But I mean isn't that what the guy in the video did, he just has a Live 2 instead of a One? And it worked for him. The only difference between what I'm doing and what he did is that he had the extra outs (3 and 4) which I don't. I have to use the master outs (1 & 2) but that shouldn't make a difference?

Being able to use outs 3/4 (or 5/6) is a huge difference. It allows you to use those two output pairs as an effects loop for the MPC.

What you are trying to do with the MPC One with outputs 1/2 to the SP404 mk2 inputs 1/2, then outputs SP404 mk2 outputs 1/2 to the MPC inputs 1/2, creates a feedback loop because there is no place for the signal to terminate or end. Effectively once you start a signal it will go on forever as it passes from one output to the next input, forever. The only real way to manage this is with turning monitoring on and off. You *can* record on the MPC One with monitoring off, but the SP404 mk2 requires you to have EXT IN turned on in order to record.

So maybe you can figure out a solution with monitor on/off on the MPC One, and the EXT IN on for the SP404 mk2, but it's not *really* going to work the way you want it to.

Good luck though, and definitely play around with it. If you can understand what is going on, and work with the signal/routing issues, it will help you better understand how a lot of audio problems come to be, and how to address them.