I just scored a cheap DP/Pro. Only the battery was dead and that was easily replaced.
The DP/2 and DP/4 boxes always draw favourable comments for their ‘quality grunge’. The DP Pro is the less talked-about, but it uses the later generation ESP2 chips (24bit). I have no reference for comparison but I am surprised at how noise-less this box is. Great!
Initial run through the factory presets revealed the best digital reverbs I’ve yet heard, and they are extremely tweakable. This will be a slow-burne – it will tale a while to know this box, but I already know that it will pay dividends. I see lots of synthesis potential.
Manual can be found here.
The factory battery was soldered in place but easy to get at. Emboldened by my first soldering forays, I managed to remove the factory battery quite easily by heating the legs and pulling. I replaced it with a battery holder – just by re-heating the existing solder joints and pushing it in. Popped-in the battery and voila – a perfectly functioning unit.
The exact battery type is BR2330, available at Farnell, but you will probably get away with using any similar 3v coin battery (at your own risk though!).