From my perspective, the R-09 input jacks seemed to have several problems that 'Murphy' made very visible to us users of the deck.
1. The two analog SURFACE MOUNTED input jacks were designed to have 2 alignment registration pins that projected through 2 drill holes in the PCB UNDER EACH JACK. These registration pins were supposed to keep the jack from moving sideways and stressing the solder pads. Furthermore, each jack was supposed to be GLUED DOWN to further keep UP_DOWN motion from again stressing the circuit solder pads.
2. As it happened, the two input jacks that were used DID NOT HAVE ANY ALIGNMENT PINS whatsoever, so NOTHING PROJECTED INTO the drilled PCB board holes to secure sideways motion, AND NO ADHESIVE was placed on these WRONG SELECTED jacks leaving the solder pads as the ONLY securing mechanism.
3. The Summer 2006 production run produced BAD SOLDERING on the jack-to-board pads that easily broke with little force, and the decks that DID NOT HAVE bad solder joints were still prone to rip off the circuit pads if the someone used straight or commonly found large right angle plugs that could easily be bumped or have the plug cord tugged to stress the jack to have even good soldered pads break free of the circuit board.
4. Many of us here found the bad solder joints and fixed these, and some of us applied adhesive to the sides of the jacks to help secure this jack to something more solid than the circuit traces.
5. It was also suggested in a few threads here for users NOT to use straight plugs AT ALL, or EVEN right angle plugs with large dimensions that easily stress the jacks by a bump or cord tug incident so a minimum of torque is applied in any case. This is also good advice for ANY MINIJACK regardless, but even more important with the R-09.
6. Edirol so far HAS NOT REPLACED THESE JACKS WITH PROPER ONES WITH ALIGHMENT PINS THAT FIT THE HOLES IN THE BOARD. However, the soldering in recent runs is good, AND THEY ARE NOW APPLYING A GOOD ADHERRING SILICONE ADHESIVE , but ONLY ON THE SIDES OF THE JACK, that while sticking well, is NOT rigid, and this still allows the jacks to move every so slightly if enough stress is applied, so there's still a possibility of the circuit pads being damaged, but much less chance now with the glue.
Users that want to glue down their jacks must understand that the circuit board has a protective coating that resists such treatment, and the plastic used in jacks is not friendly to most adhesives to stick well so choose an adhesive that is specially designed to work with difficult plastics so the glue actually holds. Cleaning with 91%+ pure Isopropyl alcohol is suggested as this enhances gluing to plastics. This is why Edirol decided on the silicone as it has good sticking properties with these materials, and doesn't easily flow INTO THE JACK, but I would prefer a more rigid epoxy made specially for holding onto plastics, but be careful with these as they can easily flow run INTO the jack and this could be a show stopper!
7. Users of minijack featured decks should be extra gentle plugging in and removing connectors, and careful with using correctly designed right angle plugs ONLY. I always treat the jacks on my own and customer's decks with CAIG LABS ProGold treatment (see my accessories page for description links) as this helps lubricate, enhance the electrical contact, and prolong the plated surfaces. The R-09 headphone jack has additional soldered pads for optical output circuitry, and is far less delicate with over twice the contact pads and surface area to the board.
8. My own and a scarce few other companies offer SAFE designed right-angle molded miniplugs that are very low profile with small flexible cord that extend the minijack connection ~10" off the deck so frequent unplugging does not happen on the deck's jack, and adapters that convert the minijack to work other mic connector types. These are suggested to prolong the life of your minideck's minijacks.
