A few years ago, my prophet 5 was revamped, and I gave the following TODO list to the technician at the time, who I still wish was local to me…This used to be stashed away in my old files section, which I’m hoping to move to this blog gradually, and better document some of the upgrades and modifications I’ve made myself, or had done by a professional in this case:
1. Replace 2 incorrect pots with the new pots/knobs
2. Clean bank select switch and fix any dim switch LEDs
3. Replace mod/pitch assembly with the new one, swapping the plastic wheels
from the old one as necessary. I’d like to keep the original one if
possible, just in case I ever need parts from it in the future.
4. Install kenton midi kit. I’d like to keep all the installation instructions
and the user manual when you’re done, in case for whatever reason it ever
needs to be removed or otherwise reversed in the future. I’d also like to
discuss the location and placement of the midi jacks when I arrive.
5. Install cassette interface, this requires a newer firmware in order to
function. I’d like the jacks for this installed in the standard location,
in between the record enable/disable switch and the cv/gate inputs.
6. Apply any relevant engineering changes that are not currently applied. Note
that ECR-10 appears to be done already. The referenced SD313C schematics
are in the first edition service manual, nothing special needed there. See:
7. Perform 2708->2716 mod as per link below, install third ROM socket, and
burn/install the 3 new EEPROMs.
8. Remove old name plate badge and perform power supply upgrades as per:
9. Install new name plate badge
10. General calibration, use updated section B for oscillator tuning, this
requires firmware 7.0c or newer, if using new custom firmware, you may need
to use the filter preset button instead of PS1+PS2 to toggle A440: