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Posts posted by kgallen

  1. Sorry I didn't realise the photos were so big - shrunk them now I've managed to get on the site via a PC and Firefox (rather than on a phone).


    7 hours ago, sfbp said:

    I think I may be the one that (indirectly) caused this. I am the proud possessor of its previous incarnation which is a simple 1->2 Toslink splitter

    Indeed Stephen, that was the first project that made me dig into the TOSLINK circuits. This new project was originally pretty much that splitter without the input receiver and wired into the machine, but then @BearBoy and myself started discussing a coax output, so I looked into that and added one.


    45 minutes ago, Richard said:

    This looks fantastic Kevin - really neat! I wonder what the chances are of somehow being able to retrofit one of these into one of the Onkyo Hi-MD decks maybe 🤔

    I'm not happy with the coax RCA socket on this v1 PCB since it doesn't have any mechanical support. The one Sony use has a screw that can be used to secure it to the case for mechanical support. The one I have used relies on the solder joints to the PCB (although I did pad out a large area of copper for mechanical support). Subsequent to sending off the PCB design for manufacture, I finally tracked down the part that Sony use (attached) and found someone on eBay selling some, albeit with the black insulator rather than the usual gold/orange for SPDIF. None of the mainstream suppliers here (RS, CPC, Farnell) stock this component. I think Mouser might list the range but I didn't want to buy a thousand or have one shipped from the US at great expense. Anyway I'm in the process of redesigning the PCB for that (larger) part, but I haven't fully tested this v1 design yet, so won't order a v2 design until that's complete.


    Regardless, this board could actually be used sub-equipped as a single or dual TOSLINK output, and as long as your machine has SPDIF internally (which it will if it uses the Sony CXD DSP chips) and 0V and +5V then it can be fitted. The electronics is easy, it's the taking apart and drilling the back panel which is the hardest part.


    I have some spare v1 bare PCBs if anyone wants one to play with. I'll let you know how I get on with the v2 and if anyone is interested, give me a shout. You lot might get a little prezzie anyway for your ongoing help and encouragement!


    I suppose what I should do is do an "all features" PCB that can be a splitter or fitted internally to a machine with whatever combination of TOSLINK/Coax outputs you want. I guess this could end up being a bit over-engineered because the splitter needs a power supply and an input circuit whereas the output board doesn't require either.


    However I guess the point is I know about all of the building blocks so if you fancy something, drops some ideas around. After all these little projects come about from suggestions/ideas/threads on here! 🙂


    Boy, it's great to be back...


  2. It has to wire into a couple of points on the main PCB (or stuffed into the ribbon cable socket before @sfbp pulls me up on that one!). The machine doesn’t need to have any digital I/O on the back panel already. 


    I’m only really familiar with the Sony machines and it should work with any as they use the SPDIF protocol natively internally. Otherwise this PCB has the interface drive circuits so doesn’t rely on the main board having any digital outputs already. 

  3. Twin TOSLINK plus coax output board.


    Transformer isolated coax output based on Sony MDS-E10 ‘pro’ output stage. The pulse transformer is the most expensive part by far (about 4GBP) but the PCB is padded out for a couple of options to mitigate against availability issues. 


    This project is partially @BearBoy’s fault 😆👍

    I subsequently found the part Sony use for the Coax RCA connector so I will redesign the PCB. I also missed one capacitor in the coax circuit. No real consequence but I’m a stickler for detail…


    I originally designed this for my MXD-D4 to provide TOSLINK output from both the CD and MD sections. However with @BearBoy’s input I added the coax output and selection jumpers so it can be used with an MD-only machine and thus add twin TOSLINK and coax outputs.


    Just a DIP 74HCU04 IC goes in the socket. 



  4. 1 minute ago, BearBoy said:

    How are you getting on with Nero?


    I did raise the iTunes issue to Apple but don't have a huge amount of confidence that they'll do anything about it. Suspect the number of people burning CD-Rs/CD-RWs from iTunes with CD Text is probably not that great these days...

    Nero is a bit clunky to use but it works. For instance it won’t access my NAS so I have to copy all the sound files to the C drive. Also understandable but annoying is it doesn’t take the title from the WAV filename, it takes it from the metadata. This means that where I have multiple instances of the same SFX, like a thunder clap (plenty of those in a Panto for the baddy) I have to go in and rename each one (since each track title includes the cue number). But the main thing is the titles seem to work reliably when dubbed to MD - both using the MXD-D4 and my existing Tascam MD-CD1 machines. So all along the problem was iTunes. I looked on the Apple forum and this issue has been reported a few of times since 2017.  I tried to back date my iTunes version to before they broke it but then it couldn’t read my libraries. Stuff it! 😆

  5. I’ve been doing similar - lots of CD dubbing using my MXD-D4. I too don’t think I’ve bought anything new - but can that really be the case - there must have been something!


    I have bought quite a lot of used discs.


    if this place holds up for more than a week I’m sure I could bore you all with project updates! No major progress but all of the projects I’ve mentioned here somewhere are still in progress…


    oh and my ‘new’ 909 stopped reading discs 😞 and as yet despite some successful calibration runs it still won’t read ☹️ using my old faithful MZ-R700 at work again.

    Cut and shut MDS-E12 is still working well - it’s on my desk where I work from home. (The missus insisted my large racks went back into the shed before Christmas - well my parents did need the bedroom put back to ‘normal’ after lockdown so they could visit!).


    I did end up buying Nero Burning ROM (software) for writing CD-R. Finally proved iTunes doesn’t write labels correctly. Dubs from CD-R to MD always had corrupted labels. 

    Panto cancelled here in Wales. All that music and SFX prep went to waste…

  6. I think I got lucky with my MXD-D4 - I don’t think he put the model number in the title, said ‘MD and CD combo’ or something like that. Other listings for this model have silly prices. I think I’ve been lucky with all my Sony MD purchases, I haven’t paid over £100 for any of them (including the ‘pro’ ones). Did pay £120 for my Tascam MD-350 a few years back and a very silly price for my first Tascam MD-CD1 as I was desperate for a dub solution - it was the first time I’d ever seen such a machine (know better now of course, partly through this forum).


    I like the 3-line display on the 909 and the metal case is very nice. 🙂


    I lie, my 770 was £107. Rest were max £80 I think. 

  7. 11 hours ago, M1JWR said:

    having said all that i missed a total bargain here


    Ouch! How did that get past the radar? Might have had a punt on that! I've had a search logged on the 940 for a while now, but not seen anything come up at a half sensible price. I keep getting 930s and 980s. (930 looks a lovely deck but I'd want MDLP. 980 is probably lovely in truth, but I got put off that one when I saw how cheaply constructed the insides were. Probably just me being snobby...)

  8. 11 hours ago, M1JWR said:

    kevin has been quiet

    Thought I'd been a bit too noisy on the other thread, so I'd give you all a break!


    As you ask: MZ-R909 at work now, been listening to it today 🙂


    TOSLINK/Coax Output PCB coming on nicely @BearBoy, will share when image uploads are working again.

  9. 4 minutes ago, BearBoy said:

    Would that work on any Sony deck lacking an optical output or just the MXD-D4?

    Many decks in theory.


    The beauty of at least the Sony decks (or more specifically the Sony DSP chips) is that they use SPDIF natively for the internal digital audio path - on the ribbon cable from the drive back to the main PCB, the audio is SPDIF 🙂 [Note 1]. This means that adding either TOSLINK or Coax output is relatively trivial. All that is needed is a simple 74HCU04 buffer stage plus the output circuit. For optical this is just the optical transmitter. For coax, this can be done "dirty" by just driving that output to an RCA. To be done properly, the coax stage should use transformer isolation as can be seen in Sony's schematics (I'm looking at the MDS-E10 now for instance). Since coax is an electrical connection, the transformer isolation avoids ground loops since the GND/0V of the two interconnected decks are not commoned together.


    Optical out is easy for me to do now as I know all of the components. For the coax I would like to do it properly, so would want to use the transformer-based output circuit. At this point in time I don't know the specs of the transformer. I suspect it is 1:1 windings, but I don't know the impedance, so I would want to dig into this and find the correct component - not necessarily the exact one Sony use, but the same electrical characteristics. I would need to find the part first, as I would need a PCB footprint to design it in. Research for "another day", but as you've raised this I might do some tentative research.


    Would coax output be of interest to you? I could probably design a PCB to support both TOSLINK and coax if of interest. For the D4 I want to make a dual-TOSLINK [Note 2]. However maybe I could do a PCB that is single TOSLINK+Coax if this is of interest.


    [Note 1] Actually the digital audio exists on the ribbon cable in both SPDIF biphase mark (refer back to our work on the Copy Bit Killer) and data+bit clock. On the MXD-D4, the DAC is a Philips part and this takes SPDIF directly (two streams, one from the MD and one from the CD). In "most" other Sony machines, the DAC is something like an AK4524 and this takes separate data+bit clock. In both cases these come straight from the drive over the "narrow" ribbon cable 🙂


    [Note 2] You have me thinking now about my own requirements... The E10 has both optical and coax I/O. The E12 only coax I/O. The 520/530/770 have optical I/O plus coax input.

  10. 3 minutes ago, BearBoy said:

    I think @Richard said he'd tried reaching out to @Christopher to find out whether it could be fixed. Not sure if he heard back?

    In the meantime I'll dub Steely Dan Aja 🙂 (in real time so I can listen, and hopefully get SP Type-R) whilst looking at the schematics to figure out adding TOSLINK output for both CD and MD. Looks straightforward. Might design myself a small PCB to make the job really tidy 🙂 (if I do there will be lots left over for give-aways 🙂 as I'll need to order 10).

  11. 3 hours ago, BearBoy said:

    Looking forward to the updates. I don't think you'll be able to post any pictures at the moment though 😧

    Well the MXD-D4 CD section reads CD-R which is great. As I trial I've just dubbed a CD-R of show music to MD at x4 rate. Seemed to work perfectly (just listening through now). Track titles are also copied. Up to now, I've been using my Tascam MD-CD1 to dub CD-R masters of show music/sound effects to MD (which are used live in the shows) but the MD-CD1 machine do have some issues with titles (in addition to adding gaps between tracks). So I'm hoping this MXD-D4 can take over those dubbing duties, which in theory means I can also create a backup MD more easily. With the MD-CD1 I would often need to go in with a PS/2 keyboard to fix titles (these are key since the titles hold the cue number) so making a second copy was always a pain... 👍

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