The thing is I heard lots of people rave about that special Akai sound
That would be primarily the "coloring" that the converters impose on the sound.
The ad/da converters on the mpc1k are nothing spectacular but they are certainly not bad. I have found that when recording form various sources the eventual recording will stay quite true to the original. I dont own an other mpc so i cannot directly compare but in my book it is a GOOD thing. As digital processing is already being the standard (meaning that unless u print direct to tape) it is commandable for an external device to stay close to the source soundwise. This is especially true if u use the digital in/outs. Would u stay as long as possible in the digital realm u will find that the mpc basically becomes an accurate recording/playback device staying completely near the original source (there is a very faint "noise floor" as the signal goes back in the puter via the digital in of ur card but this is arguably a result of EMF inside the computer).
This implies that what u put in will come out more or less the same. I didnt find the 1k to give any particular character to the sound other than a little bit of "smearing" wich is inherent to all but the high-end converters.
It is a fact that ad/da technology has improved significantly over the years since the early digital devices and the mpc1k is a good example of it. However , dont expect the mpc1k to impart an audible and distinct character to the sound. Earlier models might influence the character of sound in a far greater way wich is why these devices are still sought after.
This is due to imperfection of the onboard ad/da converters design wich will give distortion but one that is pleasing to the ear somehow.
Thus imho the mpc1k wont give u any dirt, thickness, harmonic distortion or unexpected punch to the material u put into or at playback. It is just a fairly precise playback/recording device that allows u to add any desireable effect or processing at a later stage.
As for the onboard effects section I can say (imho) that it is up to par with plug-ins and the like if not a notch better. Especially dialing in a low boost near 60hz-90Hz with te onboard eq will lift the lows (shelved that is) like few plug-ins can. Im not too wild about the compressor but if u need one take a look at the very affordable and excellent value FMR RNC wich is arguably the best compressor at that particualr price range ($199). Many top studio's own a couple of 'em (even racked LOL) and it WILL do what it supposed to do. Out of all the effects i would say i like "bit grunger" the least. I would rather have seen a dedicated distortion fx but it could have its uses. Reverb and phase shifter are quite nice. Tremolo and flying pan could have their uses as well.
If u think about outboard processing gear check out e-bay. There are many worthy devices on for sale. If ur money stretch that long i would definitely save up for a decent recording channel , with a nice preamp init plus eq and maybe a comp PLUS an outboard ad/da converter box. Some decent monitors with it and ur basically set. Wander around the site im linking below they only pimp quality gear.
http://www.mercenary.com/realniccom.html
PEACE!!

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