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Piano World forum member "Jdiggity1" was recently schooled in multiculturalism via a run-in with the wildly different wall voltage "standards" (i.e. hazardous legacy) used in various countries. He was lured into this rocky scenario, nay entrapped, by another charming divergence of said countries, that insidious and overly complex melange of market protection mechanisms and taxation schemes found at the various borders, which tends to jack import retail prices sky high. The full tale of woe is recounted here
Jdiggity's pain is our gain, however - he took many high quality photos of his Kawai MP10 in the buff after the electrician got it naked (but then had to go home to get his soldering iron, likely story) and posted
them at Imageshack so we could all leer and drool together. Let's take a lascivious look!
Here is the top of the case flipped over to show the innards. That's the trouble maker (power supply) on the left, the pitch & mod wheels on the right, the front panel display / control printed wiring boards (PWBs) at center, the "brain board" PWB above them at center, and some misc. PWBs at the upper right.
The power supply - the big chunk of iron at the fore clearly indicates that this is an older linear design. Upper center is where the IEC power (mains) jack would normally be if it didn't flame out, to the right of that is the power switch, both of which are connected to a fuse and capacitor board on the right. AC then flows to the boat anchor (power transformer), the low voltage windings of which are routed to the board at upper left where rectification, filtering, and regulation occur. Note the big fat gray cable that terminates on the small PWB to the right, this is for the front panel USB thumb drive.
Anyway, say what you will about "wall warts" but the modern switching variety are a lot lighter and more efficient than these older designs, and they normally can handle any voltage found leaking from wall outlets the world 'round.
A close-up of the fuse and capacitor board. The usual way to handle multiple insane world voltages here is to play series / parallel games with the power transformer primary windings (bottom connector) along with resizing the fuse amperage rating.
Jdiggity adds: "The three vertical lines to the lower right of the board are the voltage selector things, the middle line is the 120V 'option'. The electrician configured the board to process 240V with a simple solder job involving the far-right line there."
The linear regulator board. The large upright chip located at the bottom (behind the big electrolytic cap) is the full wave rectifier. The three regulator chips have no heatsinks, which is interesting. I wonder what that big rectifier and choke are up to?
The pitch & mod wheels seem to be using the pot shafts as their main bearings (not the best, but par for the course). The PWBs at center have I/O jacks and stuff on them, and there is a large analog board located above.
The large analog board. Many dual op-amps (NE5532N, 45800), several 8-to-1 analog switches (74HC4051), and some random transistors and caps. The center left connector has three stereo audio co-ax wires connected to it - these lead to the volume and line-in faders on the front panel. And there is a strangely empty connector at the upper right. From the high jumper count this looks like a single layer PWB.
There certainly are a lot of wiring harnesses in here! The left blue one goes to the LCD display board. There is another small I/O board located beneath the brain board.
Mmmm, brains! I see three large proprietary (house marked) QFPs. The two marked "Kawai K022-FP" appear in the MP6, as does the one marked "72030W200FP" (this may be marked "72030K200FP" on the MP6?). The two TSOP II chips marked "M12L2561616A" are 4M x 16 Bit x 4 Banks Synchronous DRAM, and these also reside on the MP6 brain board. In fact, if you look at the MP6 brain board
, it seems to be identical to this, with a few minor component population differences. Finally, and apropos of nothing I suppose, a total of 12 screws are employed to hold this smallish board down - that's some serious fastening power!To be continued... (PW only allows 8 pix/post)