Disassembling and Resoldering output to reduce noise

Some 500 players have problem about noise come from phono output or main output (which is said that mpc's thinking noise)
http://www.mpc-forums.com/viewtopic.php?f=26&t=172286&p=1639383&hilit=noise+thinking+noise#p1639383
I have same problem and I saw that resoldering the output might solve this problem.
http://www.mpc-forums.com/viewtopic.php?f=26&t=182453&p=1719748&hilit=noise#p1719748

So, I did this method and took some photos of disassembling the unit. This might be for those who wants to disassemble 500 for repairing or painting whole body.....

And after all , I couldn't solve problem.... still got thinking type noise

just open up the unit like changing the tact or pads...
I write and tape all screws to not to mix up or forget







pull the tip to free PCB


and pull off the metal plate from outputs




then pull the PCB carefully (I suggest that take screw off of the midi unit is the best way) and you can access all materials

Hey bud. I just made a post up here having discovered my 500 is noisy as well. I’m desperately hoping for a solution and was wondering if you had tried or done anything new to remedy this?

lamalta129 wrote:Hey bud. I just made a post up here having discovered my 500 is noisy as well. I’m desperately hoping for a solution and was wondering if you had tried or done anything new to remedy this?

Hi, at that time, I couldn't fix any noise problem and I haven't done anything then.....
so my 500 still has "thinking noise"

I don't know about your case when it gets noisy, but In my case, this happens only I use 500 from AC adapter and not from batteries. So I think cable or around the switch might be the cause.
But mpc already works fine if I don't care about thinking noises (especially when saving and loading) and I don't want to mess with power switch thing..... so I leave it



I also noticed that AC adapter that came with my 500 has 600mA output though there is 500mA input on the back panel on mpc.





I don't know about your adapter but this overpower might be the cause of noise but then I found website that it says it comes with adapter which has 600mA output (at least in Japan)

http://www.yodobashi.com/product/100000001000805916/

go scroll down and you'll see this (which says "Power source: AC adapter DC12v 600mA)



From this, I don't know what to do and what cause this noise thing.....

I think you just solved the noise issue. The adapter that came with mine is a 500ma. Though 600ma will work but I think the extra 100ma is causing the noise for you say, with batteries it is fine.

Also, your adapter is made from Japan, my adapter is made in Malaysia, not that it matters but different quality control and may also be the culprit.

Good observation.

I see that there is a bit of misinformation here...
No, any 12V DC adapter with enough power would work fine with MPC-500, with correct polarity (center negative) of course.

So, 12V DC adapter with 600mA would work fine.
If you happen to have 12V DC adapter with 1000mA would work fine as well.

The current (500mA, 600mA, etc.) written on 12VDC adapters basically indicate the maximum load of the adapter.
Therefore, you can use 12vDC 1000mA adapter, or 12vDC 2000mA adapter, if you want.

I would suspect that the 12VDC power adapter is the culprit here, providing noise.
This is very common issue with audio equipment. Replace the adapter with a good 12V DC power adapter.

Using MPC500 with only batteries would solve the issue, although it would be expensive...
That DC adapter is not Made in Japan by the way, it is a made-in-China unit. It is written on the bottom.

The first thing that comes to mind is what the grounding situation is with your power as well.

The cable on my original psu was broken so ordered this one at Thomann. It works okay, I don't have problems..

The only thing is my mpc500 adds noise when I'm in record mode and my soundsource is paused.. some strange 'hollow' type noise is heard. When I play music to sample from it records without noise..

Thanks Ill-Green, JVC, richie, and SlowwFloww

to Ill-Green, I hope this might help and solve the problems......

to JVC, you're right! my adapter is made in china and Thank you for the info! I didn't know that I can use any mA output if its 12v!

to richie, Unlike other mpc cable, this doesn't have ground wire on power cable....

to SlowwFloww, I will check mine to see if I hear 'hollow' type noise or not...

@SlowwFloww, that adapter pictured from Thomann looks to be in poor quality. The gauge of wire is poor and the actual shell with the led looks very reminiscent of the crap quality 12v adapters I imported years ago to sell for Linksys routers.

Some overheated and stopped functioning in days and about 30% of the order had other faults. I really suggest you upgrade to a better psu, a switching one that uses a detachable peanut cable and can function in 110/220

The reason for this noise is the cheap blue capacitors that can be seen in the following picture:
Great disassembly guide btw, good work! =)



I desoldered them and replaced them with new ones from Nichicon and the background noise was reduced to almost nothing.
See my posts in the following thread:
viewtopic.php?f=26&t=183490&p=1731157#p1731157

Edit:
The reason this occurs is, as others have indicated, due to bad decoupling (noise on the DC line).
Cheap switched power supplies are a typical source of this kind of problem. If the noise isn't there when using batteries - good for you! There probably isn't necessary to replace the capacitors .. Yet. o_O

Also: the MPC500 requires 600mA to operate, if you're using a (cheap) power supply designed to output 600mA, it is quite probable that the PSU struggles to provide the 12V that is required for operation. This will further increase the noise on the DC line and add to the noise floor in the machine.

WOW
Thank you for the information!
and disassembling was little hard but it still works in 1piece so no problem
Anyway, grad that we know what's the cause of this noise problem. Really appreciate it!

DjDiskmachine wrote:The reason for this noise is the cheap blue capacitors that can be seen in the following picture:
Great disassembly guide btw, good work! =)



I desoldered them and replaced them with new ones from Nichicon and the background noise was reduced to almost nothing.
See my posts in the following thread:
viewtopic.php?f=26&t=183490&p=1731157#p1731157

Edit:
The reason this occurs is, as others have indicated, due to bad decoupling (noise on the DC line).
Cheap switched power supplies are a typical source of this kind of problem. If the noise isn't there when using batteries - good for you! There probably isn't necessary to replace the capacitors .. Yet. o_O

Also: the MPC500 requires 600mA to operate, if you're using a (cheap) power supply designed to output 600mA, it is quite probable that the PSU struggles to provide the 12V that is required for operation. This will further increase the noise on the DC line and add to the noise floor in the machine.

fantomebeats wrote:WOW
Thank you for the information!
and disassembling was little hard but it still works in 1piece so no problem
Anyway, grad that we know what's the cause of this noise problem. Really appreciate it!

Any time buddy! Great that u managed to get it together again.
Have a good one =)

fantomebeats wrote:...
to JVC, you're right! my adapter is made in china and Thank you for the info! I didn't know that I can use any mA output if its 12v!

No, not any 12V DC adapters! If current is too low, then your MPC-500 will overload the DC adapter, and it will burn out the DC adapter.
Use a good DC adapter with enough capacity.

This is great news. Thank you so much.

So it was only the 5 caps, C907 to 912 that you replaced in the end?

I’m not completely inept at soldering but was wondering if you could circle which caps those are in your image?

Do you suspect it would be those 5 or would only a few be the main culprits? I’m getting the whining from the headphone and line outs. Mostly concerned with the line outs.