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Add optical out to MXD-D40

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Often the PCB is the same for machines in the same range and the components are not fitted and the case is not drilled for the lower machines. When that's the case, then assuming the correct parts can be sourced, then the "upgrade" can be relatively simple for those with some electronics skills - the main PCB is removed, maybe some link wires there to remove, then solder in the new components and drill the case.

I don't know if this is the case for the MXD-D40 (I'll see if I can find a Service Manual).

Where the PCB is not like this, then if the unit already has a coaxial output, then adding an optical output is in theory relatively straightforward again if you have some electronics skills. The S/PDIF optical drive signal is the same as the coax one , it just needs buffering then connected to an LED-based optical TOSLINK transmitter. It's the sort of circuit that is feasible to assemble on a small piece of Veroboard or similar.


Here it is: https://www.minidisc.org/manuals/sony/service/sony_MXD-D40_service_manual.pdf (as ever with Sony, this is a well drawn an "clickable" schematic).

It looks like they use S/PDIF internally both from the MD and the CD sections. These are input to the D/A converter IC300 on pins 15 and 16, internally multiplexed (select 1 of 2) on to the D/A section to generate the required analogue out. Schematic pages 60 and 62 and IC307 pin 12 looks of interest (S/PDIF for the MD output)... Unfortunately it looks like this is not a sub-populated PCB with the component locations ready to fill, so would need a little more work along the lines of my second paragraph above. Looking at the SM for (e.g.) the MDS-JE520 (just 'cos I have one) it looks like the optical output LED is driven directly from the MD decoder ID. Given the D40 has IC307, I think I'd be looking to see if the spare NAND gate could be used as a buffer (IC307 looks to be there because the control micro can mute the two S/PDIF streams via the NAND gates pin 1 and pin 13). The polarity of the signal would need to be confirmed to make sure an inversion was not introduced (NAND will do a logical inversion). I guess if you know any electronics most of what I've said will be self-evident, so I've probably not helped much here in the end... Conclusion: Readily do-able if you know a bit of electronics, and it would be just as easy to put an optical output on the CD section too - the signals are S/PDIF already, the MD is on IC307 pin 12 and the CD is on IC307 pin 4.

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The trick is the diode. 3.3V diodes are pretty well unobtainable now. So when you get your TOTX173 or whatever, you need to find a 5V rail, which is good because there's a 5V on the connector to/from the BD board. So it's three wires (push fitted at the ribbon cable end, soldered at the diode) and you're done. I didn't even mount the diode properly but the follow up by Cameron clearly details this. On some chassis there are spaces for both the backpanel connector and also a diode anchored to the motherboard. YMMV.

One more thing: the critical pin is the DOUT on the CXD2662 (or equivalent), pin 21. Trace that connection in the schematic and it becomes obvious (well it was at the time, 9 years on I dunno (:  )


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Doh! You’ve all been here before in spades without my daft input! Great articles on the D40 and D5C guys!

...and I’ve learned Sony did some MD/CD combo decks - daft of me I should have realised they would - maybe they weren’t available here in the UK? Techmoan seems to have one from Japan that hopefully he’ll do a YouTube on soon.


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Kevin! I always wondered what you looked like ;;;;;;;;;;

Seriously though, I enjoy his videos. Interesting that the MXD-D5C was the target of his interest. Mainly because I discovered that the Japanese domestic version would run M-Crew. I had a US-model D5C but it absolutely resisted (and still does!) my attempts to make that function work, even after my attempts to modify it (by comparison with the Japanese model, which I obtained later). I will say that he got a bit ripped off, certainly by comparison with my own experience. But I did use a different auction bidding company to the one he chose.

I already added optical out to both machines, but the other part never worked. Sadly, the whole thing became a bit irrelevant once Sony withdrew their license payments to the company that bought GraceNote, because now the automatic retrieval of CD track information no longer works with any of the old Sony products (and that goes for SonicStage too).

Nevertheless I've had it in mind to try and figure out how to make the darned thing work - the difficulty is that I don't have the Japanese schematic, only the US one.

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