First post, long time lurker. Posthaste thanks for all the advice I’ve read on here; seismographs don’t have deep well of developers and many times this forum has made my job solving issues with these things far easier.

Ok... Straight into it... picked up a new Akai MPC 1000 (music sequencer/sampler) to compliment my much larger MPC 3000. The idea was to figure out a solution to get the thing battery powered for about 2 hours so it can accompany me into the woods and such.

Takes 110-240 AC (grounded) and the PSU throws out 12v and 5v. I know next to nothing about schematics, but the AC appears to be going into a bridge rectifier/filter and then (some magic happens that I yet understand) puts out 12v and 5v to the system.

I would like to power this with a 12v AGM and hopefully not fry my instrument. Please restore my confidence or save me from destroying this!

P.S. Does polarity matter in this situation?

 

The FILTER BLK prevents high frequency noise generated by the SW POW block. That SW POW block has two +5 TABS which COULD be one in the same. They may have used two for larger current.

Then it generates +12 and -12 V. Off of P203 there are OP-AMPS which can use bipolar supplies (+12, -12).
The bipolar 12 V supplies may have to come up at the same time.

So, a +12 battery won;t do it. We also don;t know the total power which gives you a place to start in terms of battery lifetime.

You MIGHT be able to get away with a 24 V supply (two batteries) and three DC-DC converters,. You also might find what you need in one or two converters. What you don;t know id if there are any power on sequencing issues to deal with. Usually you can get a bipolar DC-DC converter.

You do need to figure out how much current is needed for each. You can use 80% for efficiency if it's not known.

 

Thanks for the reply.

Rated at 19W, which would be about 2.3 amps?

The technical depth of your response will only push me to study up more and more on schematics and circuitry.

The second 5v tab might be for the obnoxious number of drive ports and/or audio outs?

I am, however, quite confident that the internals use EITHER 12v or 5v...If I am to believe some of the more intelligent sounding users on the MPC forums.

 

Many of the OP-amps are 5532. Check the power pins to ground for +12 and -12.
The 5532 is a decent OP-amp for audio.

Power pins may not show on the schematic.

Datasheet: http://www.ti.com/lit/ds/symlink/ne5532.pdf