MPC-2000XL Rec Gain knob and Main Volume knob part numbers

Hello,

Does any one know which ALPS pot (does not have to be ALPS though) used for MPC-2000XL's Rec Gain and Main Vloume knobs?
Would be nice if some one on this board can provide parts numbers, or digikey or mouser part numbers.

Thank you,

JVC

my MPC isnt apart to measure it right now, but if yours is you can find out easily using a basic cheap multimeter.

I imagine they are audio-taper pots, but you can check that using a meter as well...just check if it's half the total resistance with the wiper in the middle, if it is not, then it's an audio taper.

honestly i bet any stereo audio pot would work. something like this:
http://www.radioshack.com/product/index ... Id=2062359

I'd advise to double check the resistance though, it could easily be 10k, 50k, or 100k, or anything.

nogginj wrote:my MPC isnt apart to measure it right now, but if yours is you can find out easily using a basic cheap multimeter.

I imagine they are audio-taper pots, but you can check that using a meter as well...just check if it's half the total resistance with the wiper in the middle, if it is not, then it's an audio taper.

I'd advise to double check the resistance though, it could easily be 10k, 50k, or 100k, or anything.

Yeah, I want to find out the resistance, since my gain pot is already damaged (fortunately it does not bleed, so I adjust gain before input), cannot find out what the taper is supposed to be.
If the taper is same as MPC-2000 classic's gain pot, then I can find out the appropriate parts for XL.

I can almost guarantee the taper is the same. The exact resistance is likely to be the same, but again, try to check.

Do you have a multimeter? It's a great investment at <$5. Time to get off the google and get to the dirty work yourself.

Also, how is it damaged? If it's scratchy, a good dose of electronic cleaner/lube deep into the heart of the thing will clear it up for at least the forseeable future.

I do have a multimeter, but since the gain pot conducts at minimum position, I don't think I can measure the correct value. I can do soldering, but my knowledge on electronics is quite elementary...

I know this much, regarding MPC-2000 classics' parts:

Digikey / mouser part #
Tact switches 688-SKHHAM
variation slider 7455 10KB2X2, 713K 10KRX2 10KB2X2, 10K ohm fader (60 x 8 x 7mm)
SCSI fuse NTE15023E

Volume pot & record gain pot for MPC-2000 Classic:
Main volume: RK0971220L25B103*2 = PTD902-2025F-B103 (BOURNS)
Gain: RK0971220L25C503*2 = PTD902-2025F-C503 (BOURNS)
The "B" and "C" indicate types of taper. The "B" is a linear output.
The "C" is a reverse audio taper. You may also see "A" at times which
indicate a standard audio taper.

BTW, the potentiometer for gain is extremely hard to find: pot with reverse audio taper is rare, and the classic uses 25mm-shaft, which is also not popular neither. fortunately, PTD902-2025F-B103 can be used for gain pot as well.
MPC-staff dot com sells the pot for both main volume and gain.

So, back to MPC-2000XL, all I need is 10K ohms, linear taper, 2-section potensiometer with flatted shaft for the gain / main volume pots?

yo JVC,
how did you find those part numbers for pots on the classic? i am looking for a volume knob for my xl and would be willing to try the classic part.
reading the spec sheet, its a 25mm, linear taper, 10k pot stereo pot.

just curious where you got this info.

thanks.

even that particular one is not easy to find outside of vst etc.

tapedeck wrote:yo JVC,
how did you find those part numbers for pots on the classic? i am looking for a volume knob for my xl and would be willing to try the classic part.
reading the spec sheet, its a 25mm, linear taper, 10k pot stereo pot.

just curious where you got this info.
thanks.

MPC-2000 Classic's service manual, which also includes part number list, is available on the net, so I used the manual to find out the info. I did find the part number, but Mouser did not have the parts anyway, so I bit the bullet and bought the pot from mpcstuff.com.

Although the resistance and taper type are likely the same for both XL and classic, 2000 classic's gain pots are physically not compatible to 2000XL; classic's pots are side, whereas XL's pot's knob stems to top.

But I think that the pots for XL are more common parts than classic's. My XL's volume knob bleeds a bit, I want to replace it, but I wish I can get the part number.

If you can, desolder the pot before it goes bad, and measure the resistance and taper type with multimeter.

http://www.ladyada.net/learn/multimeter/resistance.html

Off the topic, I'll have to replace the rotary encoder on 2000XL soon, again (I replaced it less than a year ago!) It still works fine, but it feels a bit loose now...

JVC wrote:2000 classic's gain pots are physically not compatible to 2000XL; classic's pots are side, whereas XL's pot's knob stems to top.

good to know, thanks. the pictures i have found didn't look like the one in my xl.

the pot in an xl is not exactly like the one linked above, but close. i think it's a bit smaller.

its got all the pins on one side and they go out and then bend downward, so it mounts directly to the circuit board with the knob pointing up.

im pretty sure it's a 10k. not sure on the length or taper. im hesitant to pull it out just to measure it cause that will leave my xl unusable until i put one back in. also i'm not sure which pin is what on the pot itself.

i'll hopefully report back here with anything i can figure out.

I find it a bit odd that it uses linear taper, it is usually audio taper The pot on XL, The stem length is very short.

JVC wrote:I find it a bit odd that it uses linear taper, it is usually audio taper The pot on XL, The stem length is very short.

if it's just using the voltage as control to adjust volume somewhere else, then linear makes sense.
just a guess.

tapedeck wrote:

JVC wrote:I find it a bit odd that it uses linear taper, it is usually audio taper The pot on XL, The stem length is very short.

if it's just using the voltage as control to adjust volume somewhere else, then linear makes sense.
just a guess.

Yeah, I guess, but then if that's the case, the pot doesn't have to be stereo pot. The one on MPC-2000 is stereo pot.

JVC wrote:

tapedeck wrote:

JVC wrote:I find it a bit odd that it uses linear taper, it is usually audio taper The pot on XL, The stem length is very short.

if it's just using the voltage as control to adjust volume somewhere else, then linear makes sense.
just a guess.

Yeah, I guess, but then if that's the case, the pot doesn't have to be stereo pot. The one on MPC-2000 is stereo pot.

very good point. i forgot that.

well no update on the actual part number, but for those interested, a little TLC is all my machine needed.

after i opened it up, took the volume pcb board out of it's normal position (i didn't disconnect anything), squashed it back into place, then retightened the pots, she's all good now.

a few things i learned from this is:
1) sometimes tlc will fix anything
2) the volume 'board' looks like two pots on a tiny pcb with a connecter which connects to a small wire harness (i thought they might be loose pots)
3) its not too easy to get the volume board from the front only. it looks like you need to take off the front of the machine, and go into the back and remove a pcb to make it go smoothest.

im stubborn and lazy though, so not wanting to dismantle my mpc too much, i managed to get the board out the front by using a screwdriver to 'pry' the piece of metal that the pots attach to UP just a little, and then push the volume pots down enough to get them to dislodge from their holes. this was very touchy - even if the wires were underneath the volume board, it wouldn't have enough clearance to slide them out.

i cant say that i'd recommend my technique, as the worst case scenario is that the pressure you apply could break the underlying pcb. still, i didn't want to completely dismantle the machine so it worked for me.

Well, it is potentiometer, so it will eventually wear out. Especially, those pots are not very durable ones.
MPC Stuff dot com sells that board with gain & volume for 30 bucks, which is not so bad. (It's used, I don't know the condition of the pots, but I don't think they'd sell worn out pots.)

The way 2000XL is designed, I guess pots with different size can be mounted?

JVC wrote:The way 2000XL is designed, I guess pots with different size can be mounted?

that is what i'm thinking...i bet you could just bypass the 'board' altogether and use almost any pot, provided you match the pins up with the right wires off the harness.
next time i open her up ill try to get some more details. i was kind of in a rush to get back to work when i had it apart last. did manage to give my filthy pads a good cleaning though ;]