Post your views and questions about the Akai MPC2500
By mr.pleasant Thu Mar 26, 2009 5:32 am
tick, tick, tick x1000 = it does get annoying.... ( workin on tha 2500 )
By kazakore Thu Mar 26, 2009 10:42 am
sonseelye wrote:alps sucks..and the only reason ur finding alps is because they use the same part number to the rotary encoder ....what i need is the potieometer numbers of the encoder,,i can find the part number,but what good is it?..im trying to find a permanent substitute not a replacement. if you could figure out the voltage and amps of the encoder its self,that would be much appreciated,,thanx for helpin!!


I wouldn't say Alps suck but they are kinda in the middle qualitywise. About around the same as C&K, then you've got people like Penny & Giles above and loads of generic stuff which is far worse.


Only picture I could find of the encoder (still not had a chance to have my unit apart) is from the picture of the whole board on MPCStuff and it looks very much like this Alps, except for some reason the terminals are off centre.

http://www3.alps.com/WebObjects/catalog ... J0500.html


Oh and a encoder doesn't use a potentiometer as such.


But if it gets worse with more material there to scroll though I doubt it's the potentiometer that's at fault itself. I have noticed it has been designed to be velocity sensitive, so if you rotate it faster it scrolls faster, rather than one click always being one move (or did I imagine that with the quick play I've had?) so it's also possible they've encoded some handling for different speeds depending on amount of what is being scrolled through.
By tripleb Thu Mar 26, 2009 1:57 pm
Explicit- wrote:Anybody in here who is complaining about their Data Wheel on the 2500 must have broken theirs.

My MPC 2500 turns with every click. No reason to complain here.


The wheel still sucks weather it works or not. And your mpc must work perfect cause you dont use it enough.
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By sonseelye Thu Mar 26, 2009 2:25 pm
kazakore wrote:
sonseelye wrote:alps sucks..and the only reason ur finding alps is because they use the same part number to the rotary encoder ....what i need is the potieometer numbers of the encoder,,i can find the part number,but what good is it?..im trying to find a permanent substitute not a replacement. if you could figure out the voltage and amps of the encoder its self,that would be much appreciated,,thanx for helpin!!


I wouldn't say Alps suck but they are kinda in the middle qualitywise. About around the same as C&K, then you've got people like Penny & Giles above and loads of generic stuff which is far worse.


Only picture I could find of the encoder (still not had a chance to have my unit apart) is from the picture of the whole board on MPCStuff and it looks very much like this Alps, except for some reason the terminals are off centre.

http://www3.alps.com/WebObjects/catalog ... J0500.html


Oh and a encoder doesn't use a potentiometer as such.


But if it gets worse with more material there to scroll though I doubt it's the potentiometer that's at fault itself. I have noticed it has been designed to be velocity sensitive, so if you rotate it faster it scrolls faster, rather than one click always being one move (or did I imagine that with the quick play I've had?) so it's also possible they've encoded some handling for different speeds depending on amount of what is being scrolled through.

dude ive so come to realize the more you try to scroll through the harder it gets on the "machine" its self,,meaning..if i have 12 samples on my card and no sub-folders,i can scroll with all kinds of speed,,but when i dump a gig or more on it with subfolders and all,thats when if starts acting sluggish,,so i am actually thinking its not the encoder at all but the way the "os" is set up..not to sure but i'll keep lookin and thanx again man..
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By sonseelye Thu Mar 26, 2009 2:31 pm
damn ive noticed that also,,the faster i go,the faster it will react,,,the problem is when i just want that one click,i have to click it maybe 2 or 3 times,not everytime,but often enough..
maybe i just need to learn to work with it...but if i could have the wheel off the 2000xl it would be tons better,,that thing does whatever i want it to..

funny mpcstuff. com shows the 2500 encoder looking just like the 2000xl..wonder if thats just laziness on the pic takers part..
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By Explicit- Thu Mar 26, 2009 2:54 pm
sonseelye wrote:^^you know what,,,it seems like the more samples i put on my card the funnier the reaction of the jog gets.
or if im flippin through folders instead of samples then it acts funny also...so im guessing this huge problem has to do a lot with the os and not actually the wheel...i mean i would rather have the 2000xl style encoder on it but it works and thats what matters(for now)..

Probably because my Data Wheel works perfect. Im using JJOS2
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By Explicit- Thu Mar 26, 2009 2:56 pm
tripleb wrote:
Explicit- wrote:Anybody in here who is complaining about their Data Wheel on the 2500 must have broken theirs.

My MPC 2500 turns with every click. No reason to complain here.


The wheel still sucks weather it works or not. And your mpc must work perfect cause you dont use it enough.

Yeah my 2500 just sits there and collects dust. I just stare at it and hope that one day I will use it. :roll:
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By sonseelye Thu Mar 26, 2009 3:28 pm
Explicit- wrote:
sonseelye wrote:^^you know what,,,it seems like the more samples i put on my card the funnier the reaction of the jog gets.
or if im flippin through folders instead of samples then it acts funny also...so im guessing this huge problem has to do a lot with the os and not actually the wheel...i mean i would rather have the 2000xl style encoder on it but it works and thats what matters(for now)..

Probably because my Data Wheel works perfect. Im using JJOS2

time to switch..im just frigin nervous,and i have no idea why..
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By Explicit- Thu Mar 26, 2009 3:51 pm
sonseelye wrote:
Explicit- wrote:
sonseelye wrote:^^you know what,,,it seems like the more samples i put on my card the funnier the reaction of the jog gets.
or if im flippin through folders instead of samples then it acts funny also...so im guessing this huge problem has to do a lot with the os and not actually the wheel...i mean i would rather have the 2000xl style encoder on it but it works and thats what matters(for now)..

Probably because my Data Wheel works perfect. Im using JJOS2

time to switch..im just frigin nervous,and i have no idea why..

:lol:
By kazakore Thu Mar 26, 2009 7:42 pm
sonseelye wrote:dude ive so come to realize the more you try to scroll through the harder it gets on the "machine" its self,,meaning..if i have 12 samples on my card and no sub-folders,i can scroll with all kinds of speed,,but when i dump a gig or more on it with subfolders and all,thats when if starts acting sluggish,,so i am actually thinking its not the encoder at all but the way the "os" is set up..not to sure but i'll keep lookin and thanx again man..

sonseelye wrote:damn ive noticed that also,,the faster i go,the faster it will react,,,the problem is when i just want that one click,i have to click it maybe 2 or 3 times,not everytime,but often enough..
maybe i just need to learn to work with it...but if i could have the wheel off the 2000xl it would be tons better,,that thing does whatever i want it to..


yeah that is what I was talking about having some kind of velocity reaction, so if the clicks are close together you move through the list faster. Guess it's the first time Akai have really tried to include this as it's probably only the recent machines that have large enough media drives to warrant it. Could you imagine scrolling through a list of 500 without it? At 16 pulses per revolution you would have to rotate the wheel over 30 times to go through the list (24 position encoders are also common) and with bad file management could have far longer lists. My guess is the 2000XL and other earlier MPCs were one pulse to one move no matter what, and thus more reliable in a way. (All conjecture from reading these boards and the like so could easily be wrong.) I'm also not sure if it would be the OS as such or done by a dedicated chip, making it harder to adjust the operation.

funny mpcstuff. com shows the 2500 encoder looking just like the 2000xl..wonder if thats just laziness on the pic takers part..

They show it the same as the solid shaft encoder used for the main volume knob. If you look at the picture of the whole board you can clearly see it's a hollow shaft encoder.




I did read a brief review/comparison somewhere that said even the 1k has a marginally better jog wheel that the 2k5 so sure it can be improved in some way...
By kazakore Thu Mar 26, 2009 8:32 pm
Hmmm well that's poop but it seems you can ignore a lot of what I've said. Just had a chance to plug mine in quickly at home and have a bit of a play. Just scrolling up and down the sequence list shows it doesn't seem to have any velocity sensitivity (which I admit was always a guess, as I know from experience introducing that kind of operation can cause problems.) Seems it's not always reading the pulses, so if you scroll fast you end up not travelling as far as you should (and it is a 24 positions encoder, not the 16 I had though.)

Start on sequence one and a full rotation should always take you to sequence 25. If I'm slow and steady it does. With fast rotation I've had it only get as far as sequence 15. That's missing pretty much 1 in 3 pulses. This could be a right pain if you're travelling through a long list!

Could try a different encoder but doubt it would make much difference. There is a chance you will find one that will give cleaner pulses and thus they would all be recognised by the chip that reads it's movement. Tweaking up the voltage to the encoder might help but then you run into possibility of damaging more integral component of the MPC. Or it may just be that the decoder chip isn't designed to handle above a certain frequency, which is very easily reach with fast rotation.


All I can say for now is it's looking like we're going to have to take a lesson from the tortoise and the hare. More haste often equals less speed in this situation, just relax and scroll nice and steady.


Or is this not quite the same as everybody is reporting issues with?
By kazakore Fri Mar 27, 2009 11:58 am
OK had another look at the service manual and first off I think there's a mistake in it. I don't believe the two capacitors should be in parallel to the same pin on the encoder (and I hope this isn't the case in real life.)

Thing that makes this hard is the encoder common is ground, not +ve volts, so working out good debouncing becomes hard. Can find absolutely no mention of the HD64417727f160 CPU the manual says it uses anywhere so can't get the inner workings of the chip.

Been pretty ill the last few days and got a mass on my plate of stuff I need to sort out and do but once I get a chance (hopefully early next week if I can be productive today and tomorrow) I will open my own machine, check those capacitors and see what information I can gleam from actually looking at the encoder and CPU. I do think this can be improved but some of my knowledge is a little rusty so will probably take some questions to people on another forum I know where they do a lot of design stuff based on encoders (for MIDI controllers.) It probably wont be a fix many on here would want to do themselves either...
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By eoneel Sun Mar 29, 2009 11:54 pm
sonseelye wrote:after all the stuff i read about the 4000,i happily spent my money on the 2500,ignoring the jog,,,,,,im on a mission to fix this jog,,so once i figure it out i will post a how to with whats needed!!


You would be the man of the year with that modification right there. Do you think it would help at all to the over all feel if you added a bit of weight somehow to the jog wheel? or is the feel soley the rotory encoder the jog wheel sits on.