Hello
I have a Roland Vk-7 organ and I need to change the potentiometer for the Overdrive function. It’s a D-shape one.
Unfortunately, Roland does not make this part anymore. Store like Synthaur is out of stock too.
Here are the specifications
12M/M ROTARY POTENTIOMETER EVJ 069 F01 B14
Link
Can anyone help me find something?
I live in Québec.
Thanks
Merci
Hello,
Welcome to the DigiKey TechForum. Are you able to provide a few photos of the part? Do you have a manual for the organ that may provide more information on whether this potentiometer is linear or logarithmic? How many pins does it have, does it look similar to one of these options ?
No pictures for now. They don’t show any picture on websites so I guess I will have to open my keyboard and take a picture. Thanks. Will reply to you later with a picture.
Hi echoesmike84,
Based on the info you provided above, I suspect it is a part from the obsolete Panasonic “EVJ” series. The “B14” almost certainly means “B” taper (meaning linear taper) and 10k Ohms (1 + four zeroes = 10,000). I believe the “F01” would call out shaft dimensions, though I can’t identify the actual dimensions from the number. Unfortunately, we no longer have any stock and I’m not aware of anyone else who may still have any.
I found a VK-7 Service Notes document here. From that document, I found that the Overdrive potentiometer is listed as “VR401”, and on page 22 one can see that VR401 is a 4-pin potentiometer rather than a 6-pin like I had previously thought, and that only pins 1 - 3 are connected to the circuitry.
Based on that, here’s a link to a revised list of possible 4-pin potentiometers to consider.
Roland gave me this picture. Does it help ?
Hmmm, they are 6-pin. I had thought that originally, but the drawing I found above made me think otherwise. The “EVJ Y15” calls out the series, the form factor, and the control type (volume, with no detent).
Here’s the datasheet for it: panasonic_EVJ.pdf (164.6 KB)
This is from page 4:
The only thing I don’t know is the height of your shaft above the flat surface of the pot (dimension “L” in the drawing), which I believe is called out by the “F01”. For whatever reason, the datasheet doesn’t define this part of the part number.
I believe this obsolete part, EVJ-Y15F03D14, is your exact part except for the shaft length.
Here are some pots with similar specs. Perhaps one of these could work. One might need to cut down a shaft if too long.
Hmmm, that’s goofy. It looks to me that they took a standard 6-pin dual pot and fused the outer 2 pins on each side together.
It also looks like they changed the pin spacing in the process. The standard Panasonic EVJ series parts have a 2mm pitch from pin to pin and the pin-out is as follows for all of the 6-pin parts that I found.
Assuming that they didn’t change the internal structure of the part and only fused the outer 2 pins together on each side (which may or may not be the case, though I think it likely), the pinout of your part would be like the following:
If this is what they did, then with some finagling, one might be able to make one of the 6-pin parts work, but no guarantees you’d be able to make it fit or even that the pinout I drew above is actually correct.
How possible is it that it is the below internals? With an odd external pin fuseing.
That is a possibility.
So, I should try one of the Ptt111 (mine is a 10K) ?
I honestly can’t say.
If you had access to a functional version of the original pot, you could test it with a multimeter while moving the knob to see how the resistance values change as the knob is rotated, and from this, figure out whether it has the internal structure of the PTT 111 type or the structure I drew above, or something else.
Short of being able to test a functional part, I don’t know of how to determine which structure described above, or another one, is the right choice.
You could order one or more of the potential options and try them out. However, there is always a possibility that the wrong type could damage it. I think that is not likely, but always a possibility.
