Distinction:

I have a long and complex history with the Alesis DM Pro. It’s a uniquely powerful and expressive device, specifically in how one can custom-program both natural and novel drumming expression between modulation Sources

• hit velocity
• hit rate (think “swells”)
• random variation
• many others…

…and the resultant sound controls.

• pitch
• amplitude gain and envelope controls
• filter cutoff and envelope control
• many others…

I spent a LOT of time programming and personalizing it to get the most flexible e-drum system I could out of it, and as it’s outputs started to fail, I realized I could keep the unit and dump all my hard-earned programming into a new (likely cheaper) unit.

In fact, I picked up a second DM pro that was in rough shape for spare parts or frankenstein-ing.

The Brain’s brain fails:

However, when I booted it up this month, I started seeing scrambled patch names, and when I tested it’s saving of trivial changes, it failed to retain them. I immediately (re)backed up all my DM Pro kits and Globals into SoundDiver.

In this unit, like most programmable gear from the 90s, patches are stored in (non-flashing) memory chip(s)  powered by a coin-sized battery that keeps them charged while the unit is powered down. Whenever a unit (especially from 80s and 90s) starts wiping all the presets, check for a little coin battery.

 

To the Bench 

Opening the DM pro up is tricky.

 

 

 

Spec:

for reference: this project involved.

• initial purchase of a Panasonic BR-2325-HG panel-mounted battery
• upgrade to CR2025 coin-button battery holder

 

Practical Problems of Polarity

 

…but the incoming battery only has two, so I have to “get it right”

Making it fit:

 

 

Power ON ?

after reversing the process to re-assemble the parts enough to power on, I found the unit suddenly showed symptoms WORSE than “memory wipe”

it Showed NO screen or response to front panel board.

Before panicking, checked my work and realized I’d mis-mounted a standoff.

After remedy of that mistake, I everything worked fine, and it could now save patches through  power cycles (again), so I reassembled the unit for future use.