Jump to content

kgallen

Members
  • Posts

    1,068
  • Joined

  • Last visited

  • Days Won

    4

Everything posted by kgallen

  1. I doubt anyone is looking, but there is a Tascam RC-8 listed on eBay UK at the moment (at a moderately healthy price): https://www.ebay.co.uk/itm/Tascam-RC-8-Wired-Remote-Control-RC-Unit-for-MiniDisc/133446843259?hash=item1f120d3b7b:g:xzwAAOSwO5BeXtLn
  2. For other readers who are wondering what we’re waffling in about, here is a Wikipedia article talking about one phenomena due to a manufacturing issue: CD bronzing A few months back I purchased a second hand Compact Disc that seems to exhibit the above. It wouldn’t read. It was an 80’s CD from the period and ‘Made in UK by PDO’ so quite likely from the cited Philips/DuPont manufacturing plant. I’ve not seen this particular phenomenon on an MD (I’ve a sample size of 2 for MD-CD though!).
  3. At last. I was getting bored of cheapo-"VU"-meters videos. Back to good 'ole MD :-)
  4. We're largely not interested in the top side of the disc, so long as it's not in a condition that would damage the overwrite head. All of the "magic" is the inner layers of the disc, sandwiched between polycarbonate layers for protection. The optical transparency of the underside so the laser can "see" the MO and reflective layers is key to reading the disc. During recording, the OWH creates a (relatively wide) magnetic field that permeates to the MO layer whilst the laser spot-heats to the Curie point (185degC for the alloy used in MD) from the underside to record the single binary digit at that disc location. Rinse and repeat. Here is a diagram of the "disc sandwich" from the Minidisc Technical Primer from minidisc.org : Here's the statement on the OWH contact for all you "lube fan-boys":
  5. Recording spot-heats the disc, so this probably drives off any moisture that could cause oxidation of the disc surface. The discs you experienced this with, were they still in their intact wrappers prior to the use you describe? I've only seen this (or similar) on one disc - a TDK MXR that I'd had for many years (well since ~1999). On one part of the disc it had what looked like small rust spots on it. It would not read.
  6. Sounds like the internal power supply to me if the whole system freezes, rather than just an audio issue. Possibly the power supply going into shutdown through a heating issue or a component that drifts out of tolerance with heat. Could be just one of the rails, possibly a controller logic rail (say +5V) if there are signs that "something" is still on but the system is otherwise non-functional. The popping might be due to the rail rising again briefly before shutting down again. Probably not a user repair, but it would be disappointing if a general electronics service technician wasn't prepared to at least have a look. Diagnosis might be tricky but I suspect the fault once found would be relatively easy to fix. Being able to offer this Service Manual, that does at least have the schematics, might help (and possibly around the circuit of Q101): Service Manual: https://elektrotanya.com/technics_se-hd501.pdf/download.html Needs more diagnostic work to narrow down the problem area. It looks like a modular system, so if you unplug various sections and test, what can you ascertain about when the fault shows and when it doesn't? (Accepting with the CD disconnected you can't play a CD...)
  7. Writing the titles is the same process as writing the audio data. On the basis of that argument, the best way to "save your machine" is to never record an MD. The audio data on an MD is around 200 megabytes (say 200,000,000 bytes). Any titles will be at most a few hundred bytes (say 200 bytes). Go figure! Maybe this tale comes from the AMS knob "wearing out" selecting each of the letters. From experience, using that method is more wearing on the human performing the labelling process than the machine! Glad your deck is back to life, heartening to hear!
  8. Don't know about the internals of this machine, but sounds like a weak eject belt if it has such a thing. I would try and give it some assistance from outside when trying to eject, maybe some tweezers or fine-nosed pliers. Not to pull out the disc, but to just try and help the mechanism when it tries to eject. If it's stuck halfway then you might have to help it back in fully then try the eject again. Otherwise it's a similar process with the lid off - usual warning about mains electricity. Then it's locating and fitting a new belt it it is such in this machine. To be continued... SM is here: https://www.manualslib.com/download/754470/Onkyo-Md-105.html Parts lists page -7- have "loading gear", but I don't see a mention of a belt yet...
  9. So the PCBs for my little TOSLINK splitter project arrived this morning and I've built a couple up and they are working a treat. One of these is for me and the other for @sfbp to replace his broken one. Hopefully this design is a little more "Stephen proof" :-P . I have a few spare PCBs (unpopulated), so if anyone in the UK wants one, then PM me some details and I can pop you one in the post with the schematic. You'll have to source your own components and do your own soldering, so please don't ask if you're not up to this - giving stuff away for free does imply the recipient won't waste such gifts at the expense of other who have genuine need. If there is a lot of interest I will allocate in preference to regular/active contributors on this Forum.
  10. :-( Hope this doesn’t mean an end with minidisc for you...
  11. @NGY no problem! I’m 0 for 2 today :-( but in good company of the truly knowledgable! ;-)
  12. Interesting question. Portables of course have to work at any angle. Whilst the mechanicals of a deck are different and by default would expect to be horizontal I would expect the tight tolerances and low mass of the MD drive parts would be fine. I don’t think I’d have any worries about playback. Record would be a minor concern but the OWH is such a tiny lightweight part I doubt gravity would be an issue!
  13. Ok I did some research. US is 120V +/-6% -> 112.8V to 127.2V Japan is 100V +/-10% -> 90V to 110V So US equipment needs to work down to 112.8V and Japanese up to 110V. Internally, one logic supply rail is 5V. The unregulated supply for this would be 8V (minimum). In the US this would require a 112/8=14:1 transformer. For Japan a 90/8=11:1 So if we stick US 127V into a Japanese 11:1 transformer we would get 11.5V out. This 3.5V difference at the regulator input will result in slightly more power dissipation from the linear regulator. At the currents used by this equipment I would expect this to be easily accommodated in the thermal design. My MDS-E12 has a power select switch 100V or 220V. I think the intention here is it can be used on ~100V supplies (US/Japan) and ~220V (Europe/Asia/Australasia) supplies quite happily. Comments?
  14. I bow to NGY if he thinks the below is wrong or others in the local area that know the specs. I would compare the power network operators voltage specification for the US versus that of Japan. You may find that the US 110V +/- % spec versus the Japanese 100V +/- % spec overlap such that you can use the product as-is on the US supply without issue. For example here in the UK our supply was nominally 240V ac, but in order to harmonise with the European supply of 230V ac, the spec of the UK supply was changed. No one changed any equipment either in the power distribution network or in their homes. This was a paper exercise only. The point being that equipment built for the European market is perfectly at home in the UK, or even Australia with its 240V supply. This equipment generally uses a transformer. The result of the step-down means that the input being 110 or 100 will result in a much smaller change than 10V on the secondary. Find the specs, do the maths. Any other reason the two power supply scenarios differ that affects the conclusion? Supply frequency is not an issue. US is 60Hz but the spec label on the unit shown above allows 50Hz and 60Hz.
  15. That's true from my failed searches! Yellow-ringed RCA sockets you can get. I've not found an orange one anywhere - except on that stacked TOSLINK/Coax part I listed above from CPC.
  16. I'm on the case. Might have a little gift for you in a few weeks... (months...!)
  17. MDS-JE480 I'd expect, it's a sub-equiped 980! Never done it but my assessment would be this is not a trivial job - mostly down to the desoldering required to remove the old one first. No doubt some have done it but to do it you'd need a donor drive and I'd just fit that one instead.
  18. Stephen, I bumped into this thread of yours from way back - actually similar to the reason I was looking at TOSLINK RX/TX several hours ago which lead me to the writing of this thread. I was thinking how to duplicate the TOSLINK out from my PC to both my MDS-JE520 and the MDS-JE480 - the latter that has made it in from the shed to the office since I wanted to record a lengthy radio program in LP4 (beloved 520 being an SP-only machine). I'm thinking I might make a small project of this and address some of the design weaknesses that lead to the demise of your splitter (like a 5V reg as @NGY suggested there). Between @NGY musing an IOP breakout board and myself, seems there might be a little cottage industry in 2021 with some mini MD projects...
  19. @M1JWR - with this last batch of machines do you need to reconsider your comments on addiction made in this post ("addiction in my case, not sure")? You're hopelessly hooked now like the rest of us! Keep it up!!!
  20. :-P That's fine, Simon. Where the PCB is already designed with the various options for optical/coax, then the suitable parts need to be purchased and soldered into the designed-in locations. At most a couple of Rs, Cs are needed plus these hard-to-find optical modules. I'm still scratching my head to understand why my Pro E12s don't have the optical I/O since the E10 has and the PCB is the same. On a £750 machine (as was at new) they've saved a couple of pounds off the BOM by not fitting the RX and TX optical, a couple of Rs, Cs and ferrite beads.
  21. No, I've no idea now why I started doing this, but as I did, I'm writing it down! There are some topics here on this forum regarding adding optical I/O to those decks that had such features cost-reduced away. Narrative seems to be that the required 3V diodes are hard to find these days, and certainly looking at the part specified for my MDS-JE520, it seems indeed that the original Sharp devices are obsolete. Also noted in some posts are a Toshiba part, e.g. TOTX173, but this also seems obsolete. However having a browse around I did end up at some Cliff components that are readily available and so far as Farnell's labelling goes, are a "Best Seller", so let's hope they stay available for a bit longer. So here goes and sorry if you all already knew this... Based on the Sony MDS-JE520 Service Manual, the original parts were Sharp GP1F38 series 3V devices. These used the separate plug-in "dust plug". The newer Sharp series use the inbuilt flap as do the Cliff components parts that seem available at least in the UK. The newer Sharp model and the Cliff model match the original Sharp model on mechanical dimensions and light wavelength. However the newer models have a wider operational voltage range that suit both 3V and 5V designs. Check the Service Manual for your Deck to see if these parts are also suitable for your machine. Note also Cliff seem to number the pins in the reverse order to Sharp, but based on the mechanical drawings the same physical pin position is the same signal/supply as the Sharp part. Transmitter Sharp GP1F38T -> Sharp GP1FAV31TK0F -> Cliff FCR684205T (OTJ-5) CPC (£1.36) Farnell (£2.83 - yes CPC and Farnell are the same company, go figure on the pricing...) Receiver Sharp GP1F38R -> Sharp GP1FAV31RK0F -> Cliff FCR684205R (ORJ-5) CPC - not stocked Farnell (£4.19) Prices as of Dec/2020. These components are also listed by others on eBay (including in the US) at suitably inflated prices. I couldn't find either of the Cliff parts listed on Digikey or Mouser. If you happen to be doing a DIY-job, Cliff also do a neat combined TOSLINK optical RX/RCA(coax) module ORJ-6. The two parts have separate pinout and whilst the TOSLINK is an optical receiver, the RCA jack is just a socket, so you could use for either input or output to suit your needs. This product won't fit into the PCB of any of the Sony decks but you might find it interesting for your own project/design. CPC (£2.36) Farnell (£5.80, yup...) Example thread:
  22. I thought the same about the various MDM-7SC drives in my Pro units (E10, E12). But there does seem to be a small difference for some reason, maybe firmware on the drive? Had similar ‘not fully playing ball’ issues with a 440 drive in a 480 (Type S) which is essentially what you have, although I was never sure if that was down to the 440 drive seeming a little fickle even in its own machine. The ribbon sizes and positions should be identical on your 940/980 so I’d give it a try although as above x40 is not Type S. Otherwise see if the OWH is swappable. I think electrically it’s a 2pin header although mechanically it might be very fiddly.
  23. Cheers! I've ordered some of them too. I'm going to be overrun with belts now :-D
  24. https://www.ebay.co.uk/str/gersbachsoundtechnik 15 x 1.0 was about the best I could find. Original seems to be 17 x 0.8 but I can't find this size anywhere.
×
×
  • Create New...