Distortion issue with samples

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Distortion issue with samples

By Dillionaire_ Thu Jul 23, 2020 10:52 pm
Hello I'm somewhat new to MPC's and I've been reading the manuals and leaning the basics over the last 6 months. I started with a MPC4000, since I've had it its been great. Last night I was jamming and trying to finally piece together my small studio with a few machines.

I have been loading in samples from a USB stick without problems until now, when I woke up today and started to jam on the MPC, almost all samples on my USB stick are distorted as hell. Some samples work and others no, its confusing the **** out of me because yesterday it was all working piece of cake.

I've tried to reset to factory settings, I've reset the system clock at 44.1khz. I cant really see what else I can do in the OS to fix the problem. I experienced something similar when I thought I could load in 8 bit samples from the internet and got a similar sound when auditioning in the load screen. To me it feels like the bit rate is all **** up but honestly I don't know, knowing my luck with gear it will be a lemon.

I will pull the thing apart today and clean everything but before I do that has anyone experienced this?
I will try taking the RAM in and out for tests too, I saw that somewhere and looked like a good idea.


Thanks guys.
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Re: Distortion issue with samples

By Lampdog Thu Jul 23, 2020 11:51 pm
Try reseating ram. When ram goes bad or is not seated correctly you get random distortion in samples since those samples are IN ram.
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Re: Distortion issue with samples

By Lampdog Fri Jul 24, 2020 1:14 am
Post again when you figure it out.
Maybe someone else can learn from it.

Re: Distortion issue with samples

By Dillionaire_ Fri Jul 24, 2020 4:03 am
Lampdog wrote:Post again when you figure it out.
Maybe someone else can learn from it.


I've taken the ram out, swapped it to the other side, cant read it, seems the stick is not clipping in well to its mount either.

I've taken the ram out entirely and re-booted since no matter what I do its only showing the 16mb internal storage on the motherboard.

I've loaded some samples to the hard drive and tried to play back some samples from there and they are also completely distorted.

Starting to wonder if its something wrong with the motherboard or cabling in the machine. Not to sure where to look but ill get into the service manual, if anyone has had this please shout out any tips would be appreciated!

Thanks again
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Re: Distortion issue with samples

By Lampdog Fri Jul 24, 2020 5:49 am
If your getting distortion even with default 16mb mobo ram then could it be mobo itself?
8 out board, do you have it and if so is audio go through it?

Re: Distortion issue with samples

By Dillionaire_ Fri Jul 24, 2020 7:54 am
Lampdog wrote:If your getting distortion even with default 16mb mobo ram then could it be mobo itself?
8 out board, do you have it and if so is audio go through it?



I don't have the 8 out board, I'm getting thrashing white noise in the headphone jack too.
I guess I'll have to try stick this new 2x ram sticks in when it arrives.

Thanks for your ideas lampdog, I'll maybe pull the boards out and try clean everything before I start buying parts.

First thing I would buy is the output board then maybe motherboard if that fails.

Next step will be recycling bin :(

Re: Distortion issue with samples

By Dillionaire_ Fri Jul 24, 2020 8:20 am
Is doing a new OS install worth giving a crack, seems like it will do nothing to me but idk I'm worried about pulling it all apart and making it worse than when I started
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Re: Distortion issue with samples

By Lampdog Fri Jul 24, 2020 1:50 pm
Akai MPC4000 Service Manual wrote:OS Update Procedure
[OS Update procedure from USB]
The OS update can be made from the PC via the USB port.
You must have the “OS loader software for MPC4000” besides the OS .bin file.
The OS loader software includes the OS Loader.exe file, USB driver.inf file, and USB Driver.sys file.
1. Install USB Driver to your PC
After all files are un-Zipped, place the USB Driver.inf and USB Driver.sys files into the same folder, e.g. Driver.
Boot up the PC and MPC4000 complete and then connect the sampler to the PC using the USB cable.
This prompts that the PC found the new device an d the new driver is required.
Refer it to the Driver folder you just created.
The Driver software will be placed correctly and the MPC4000 is recognized properly.
2. OS update
Double click on the OS Loader.exe icon and specify the OS .bin file. It will send the OS to the MPC4000.
[Caution]
After the update, be sure to initialize the MPC4000 by pressing the GLOBAL key, and then [F6] (INITIAL)
and [F5] (DO IT) keys, before turning it off.
[OS update procedure from CD-R]
To update the OS from the CD-ROM, it requires the OS version later than V1.02 software installed on the MPC4000.
You can update the OS from the CD-ROM drive. Be sure to use the CD-ROM that contains the OS for the MPC
4000. You can create the OS disc by using your PC’s CD-R/W function to write the “MPC4000.bin” file on to an
ISO9660 CD-ROM disc.
1. Turn the MPC4000 on and insert the OS disc.
2. Press the LOAD key and select the MPC4000 OS file (.bin file).
3. Press the [F6] (DO IT) key and then the [F6] (INSTALL) key.
4. The OS Update progress appears, i.e. the messages “Please wait ??.” and then “Upgrading of the Flash
ROM was successful.” appear accordingly.
5. Press the [F6] (Restart) key. Be sure to initialize the MPC4000 by pressing the GLOBAL key, and then the
[F6] (INITIAL) and [F5] (DO IT) keys, before turning it off.

Re: Distortion issue with samples

By dryad-66 Sat Jul 25, 2020 11:34 am
Yo,Had the same kinda problem recently with distorted samples and general machine bad behaviour and it was the FX board that can go bad.Unfortunately it down under the boards facing the bottom of case.Would be worth going down there and popping it out,reassemble and check again.If its ok go back inside clean the slots and pins (it pops off with slight firm pressure from a screw driver or something less dangerous to the boards) refit and repeat the procedure.Left mine out because it was obviously faulty.I had to change one on a Z8 a couple of years ago too.Was happy to find it was just that.

Re: Distortion issue with samples

By dryad-66 Sat Aug 01, 2020 1:19 pm
dryad-66 wrote:Yo,Had the same kinda problem recently with distorted samples and general machine bad behaviour and it was the FX board that can go bad.Unfortunately it down under the boards facing the bottom of case.Would be worth going down there and popping it out,reassemble and check again.If its ok go back inside clean the slots and pins (it pops off with slight firm pressure from a screw driver or something less dangerous to the boards) refit and repeat the procedure.Left mine out because it was obviously faulty.I had to change one on a Z8 a couple of years ago too.Was happy to find it was just that.


Ok update.Turns out my problem was not with the FX card but with the lower boards not connecting properly via a clip together connection.Creating all kinds of crazy.You would have to take all lower boards out,disconnect one from the other and pop/clip them back together.While down there do the same with the FX board.My boards need to be Screwed back to together in such a way as to not create a disconnect again.Anyway saved my machine as it was just getting worse and was unusable.Plus i got my FX back !!!!! Very happy now “ ]

Re: Distortion issue with samples

By Dillionaire_ Fri Aug 14, 2020 8:47 am
Update: I have received 2x RAM sticks and installed them, not showing any further ram when booting up the system. Now that I've tried that and failed I will take apart the boards and see if mine is also a connection issue. :-)

Re: Distortion issue with samples

By Dillionaire_ Sun Sep 06, 2020 6:52 am
Update: I've taken the machine apart several times, cleaned everything and put back together, I've checked the boards for cracks, corrosion or anything obvious. Unfortunately still, the outputting audio is a rattling white noise. I will try to get my hands on a multi meter to test the output board for damage, however the thing that confuses me the most is no matter what ram I put into the unit I get no sign of it registering in the machine, just the onboard 16mb of memory is all that shows.

I also purchased a 5000 to play around with in the meantime but that blew up too after 7 days of having it. Not having the best of luck out here and there's no one to help with servicing in my country. Guess Ill try do as much more trouble shooting as I can then look at buying a whole new motherboard. That's gonna hurt the wallet, probably easier throwing it in the bin and buying another machine.
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