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From the factory, all of the SPX-90 Presets are maintained in Static RAM backed-up by a 3V lithium battery when the unit is off. If a user forgot to replace the battery every 5-years or so, all of the presets would be erased and the the user would have to reload the factory presets from the internal ROM.

To replace the back-up battery the unit has to be de-racked, the top and bottom covers need to be removed and the 3V lithium battery has to be un-soldered from the circuit board. The factory battery has two solder tabs spot-welded to the battery to allow soldering of the raw battery to the circuit board. This battery is impossible to find easily so some shops will solder in a lithium battery holder on the circuit board. This would make it easier to replace the battery without soldering, but, the unit still has to be de-racked and the top and bottom covers still need to be removed.

My mod involves running 2 wires from the battery locations on the circuit board to a 2 x AAA battery holder mounted on the the rear of the chassis. The wires are routed through a 9/32" hole drilled in the chassis and a rubber grommet.

Changing the two AAA batteries is a snap as the unit does not have to be removed from the rack...if you are fast, you can replace the back-up batteries without erasing the memory!

If you are slow, once you have removed the back-up battery your presets are toast so you must remember to do a bulk-dump of you presets to a MIDI Manager/ Librarian. I use the Midi Tool Box App on my iPhone© with an IK Multimedia® iRig MIDI© appliance to store the sysex data for all of my FX processors and any FX processors that come in for modification.



I hate rackmount gear that is tethered by a power cord... especially when you have to de-rack it and you have to "clip" cable ties to release the cord. I removed the stock power cord and Heyco© strain-relief and cut the chassis to accept a standard IEC power inlet that would accept a removeable power cord.




The Glue used to secure components on the SPX 90 Power Supply Board, after a long time and heat exposure, will eventually become conductive causing the power supplky to fail...this SPX90 was not exhibiting this problem, but, the glue was scraped away from all components as preventive maintenance.

The Power Board was removed from the chassis and all of the solder joints were re-flowed to negate any cold-solder joints that may crack in the future causing intermittent operation.