Sampling Using 3rd party A/D convertors

Anyone bypassing the AD on the MPC and sampling through external sound card via ADAT? or SPDIF?... seams like quite the luxury to be able to slap apogee converters on you MPC any feedback on difference in audio quality would be appreciated in this regard.

I have a RME interface sitting next to me that has superior conversion, I´ll be hooking it up this week and I´m going to hook it via ADAT in...had a few question read up on most of them, but I thought I´d be setting the sync (under misc) to: ADAT IN but then I read this

-"Internal" Synchro in the mpc (the only one that seems to work fine if I want to synchronize everything together).

so witch is it?, to me logically it would be ADAT in since I´m sampling via ADAT
.. and what happens if the ADAT is out of sync? no audio? inferior audio (binary out of sync?)

I mean that´s what the digital sync refers to right? 0s & 1s syncing from both ends, correct?..

another; you can only send 44 or 48k at 16 bit/ Nothing @ 24bit!? correct?..

for anyone using the RME sound cards.....your ADAT will not work if you have the AEB board also installed....since this uses the ADAT internally....

http://www.mpc-forums.com/viewtopic.php?f=2&t=121692
worst quote I found .. AEB standing for: analog expansion board .. but I´m not sure what logic is behind this is> if you have the AEB your ADAT can only refers to its internal clock..

Like I said I´ll be testing this next week, I´ll drop feedback on 24/96 MPC vs 16/48 RME sound quality,.. until then any pointers appreciated

im about to hook up a ua 2192

thing is, when you get this to be silent whith ssd and new fan its perfect as a mastering device. (editing ,96k, and external comps and eqs. one pad for each track on the album. etc)

I dont know how silent you can get it though


but for instruments i prefer the 4000 ad over my ff800

Wow OK ... that was a surprisingly pleasant reply, I didn´t think the Akai convertors would compete with convertors that cost as much as a MPC, but from the studios I´ve brought my 4k too I´ve always gotten a comment on how good it sounds,.. very detailed and crisp

personally I´ve been disappointed with it when sampling dry analogue synths .. it seams to lose too much of the round warm analog sound to the crispier detailed character of the MPC.. which is always great on drums ..

but for instruments i prefer the 4000 ad over my ff800

would you mind going into more detail on that, what are you monitoring on whats in your signal chain, what are you sampling etc ... thx!

thing is, when you get this to be silent whith ssd and new fan its perfect as a mastering device. (editing ,96k, and external comps and eqs. one pad for each track on the album. etc)

you can get very silent with ssd crad & silent fan, yes the 4k is silent enough to be in a pro environment but how practical is in in a mastering environment

Well sample the same thing twice with both convertors, then combine the samples, flip the phase on one and see if there's any difference at all!

i've done a/b comparisons of drums/synths/etc. sampled directly into the mpc and those sampled into ableton. i prefer what the mpc imparts on the samples - "crisp"-ness, what-have-you. however (and this i believe to be most pertinent), i've found that my echo audiofire interface imparts ZERO artifacts/characteristics to the sound.

this i feel is the primary responsibility of an ad/da converter - be as transparent as possible. if you want no effect, use your nice outboard converter. if you like what the mpc does, use that. i contend that there is a difference and that either could be preferable.

- jim

Well sample the same thing twice with both convertors, then combine the samples, flip the phase on one and see if there's any difference at all!

I´ll get back to you...

Ok better late than never ...

So I wanted to do a very detailed test and all with graphic display and Hz range measurements but to make a long story short I got kicked out of that studio .. not so much my fault the studio owner was a wackjob .. anyway..

So I´ll just leave my written conclusion.

I sampled at first a TR-505 beat, I thought its static drum sound would be a good way to compare the two convertors using phase cancellation... in the middle of it the batteries failed in the 505 but I did notice a difference so I skipped though flip phase test as there´s an audible difference to start with ...and I was running low on time

so next I sampled a full on tr-808 beat with bright highs and low-lows (large audio spectrum)
when monitoring I played the sampled TR808 back at original speed an octave lower and an octave higher side by side, sampled straight into the mpc and straight into the RME and straight through the RME into the MPC

Monitors used BM5as

and the verdict really surprised me


RME Fireface 400 (direct in)
its got more presence in the bass, the highs are rounder, the sound is a little more musical if you will, over all more details, smother dither generation or quantization if you will..


MPC4000 (direct in)
crispier sound, the mid highs seams to be a bit compressed, the highs where more sharper overall (due to the lesser quality dithering prehaps.. but the differences to me where minor .. these where not so noticeable unless you focused on which one was playing, anyone walking into the studio could have cared less..


MPC4000 (sampled via RME adat)
A slight improvement over direct in, the sound gains a bit of the RME qualities but as said the difference was minor to start with so the improvement was on a minor scale .. what was surprising is that when I played the audio back out though ADAT in on the RME is that it still retained that compressed mid range characteristics even when bypassing the Akai convertors completely


Conclusions
Although its not a a very scientific test , no sub bass monitoring for starters; the 2002 model MPC4000 holds ts own next to a muliawarded RME audio interface, the difference where minor enough to not bug me but you need to put this into context,

if you where tracking multiple tracks these minor differences will start adding up and at the end of the day the difference will matter greatly, the RME will sound more musical and rounder and I´d defiantly sample vocals and the alike through the RME if I where to pick one..

if you wanted add some pump into a beat, this compressed mid sharp/colder Akai sound might cut more in the mix vs recording them through the RME, basically with the MPC you gain a certain charterer, and this might do wonders for your mix vs recording everything through the same A/D

Basically the convertors on the MPC4000 are fine, wouldn't want to track an album on it but I´ll continue to sample vinyl straight into it without worries, it a nice flavor to have even next to pro level convertors ..




some RME 400 info
tech specs here >http://www.rme-audio.de/en_products_fireface_400.php#5
rewards here
http://www.rme-audio.de/en_awards.php
reveiw here
http://www.soundonsound.com/sos/jul07/a ... ace400.htm