Monday, November 5, 2012

Sampler maintenance and upgrade

A proper Prophet 2002 repair and upgrade

I actually found a guy selling a 2nd hand R-235 potentiometer as well as the knob that goes on it. I got it in my mail about a week ago and tonight I decided to remove my ugly replacement and put the right part in.
While I had it open on my workbench I also decided it's a good opportunity to install the Lotharek SDHxC SD card floppy emulator.

Replacing the potentiometer

This was something I wanted to do ever since I installed my stupid replacement. OK, my replacement worked, but it wasn't pretty and I didn't have any knob that fit.
I got another SCI knob for it, but since the D-profile on the pot axis is "backwards" on the SCI-pots I had to use a standard pot. I chose to forget about the whole thing...
...until I found this guy who was taking parts from an old Prophet 2002. He was willing to sell the R-235 pot with the knob to me. Excellent! So, I bought it and opened my machine up.
Useless photo of the Prophet 2002 Plus opened. Temporary pot visible on the left.

Floppy out, SD-card in

As I mentioned earlier, I had a floppy emulator waiting to be installed.
The process was quite straightforward. A small problem was that the relatively cheap 3.5" case made for the floppy emulator didn't have the right mounting holes underneath (2 were missing). This drive is mounted using those holes and not the ones on the sides as is common in PCs for example.
Those holes were slightly off and they were just that, holes. You had to use some force and use the screws as screw taps to force some threads to form in the case before trying to mount it.
Here's a pic of the floppy emulator installed where the drive used to sit.
All that dust wasn't there when I took the photo. I swear.

With the emulator, you get a light and a dark self-adhesive front. I naturally went with the dark one.

There was also some jumpers you could set to choose device ID. I just put one across A0 and hoped for the best. Seemed to work...
There's a bit of space between the floppy emulator and the panel. The old front that used to sit in front of the disk drive obviously didn't fit over the emulator so I guess I'll just have to live with it, and I think I can...

Here's a photo of the Prophet 2002 Plus in the rack.

Data knob is replaced and floppy emulator in place of old disk drive.

Though I must admit, I didn't really try it properly. I just pressed some buttons and it started doing a lot of disk operations. I think I loaded a soundbank from an empty disk, heh... I never even tried using the normal disk drive before removing it so I have no idea how this thing works :)
I wasn't interested in using it in the state it was in before, and knowing I was going to replace the drive with the emulator.. well.. I just didn't wanna bother with it until then.
Now I have no excuse!

So soon, hopefully, it will see some use :)


  1. If you wish to sell your unit i would love to buy it.
    carlt at

  2. Peter, is there any way you could share the firmware from your 2002 Plus with me? I have a regular 2002 that I want to add individual outputs to, but I'll need the later version of the firmware. I have an eprom burner, just need a copy of the software!