HOWTO: S/PDIF Digital Output for MiniDisc Portables...

[raintheory]

This looks promising...

Haven't tried this myself, but might well be worth a shot if you have some extra portables lying around that you don't mind hacking:

“Here’s a very trivial S/PDIF transmitter hack for portable MiniDiscs and other digital audio devices lacking S/PDIF output.

The S/PDIF transmitter runs from +5V, 44kHz 16bit input at 384xfs, is set to consumer mode output, and doesn’t transmit any COPY bit (copyright protection disabled). The board can be connected directly to a PC motherboard, or via a Toshiba TOTX173 to an optical cable feed, or with a small transformer to a coax line.”

http://users.tkk.fi/~jwagner/electr/minidisc-spdif/

The MiniDisc reference/instructions are about halfway down the linked page.

Edited February 1, 2007 by raintheory

[=PK=]

Hello!

I'm not that good on english and electronics but... what is it for?

Thank you!

[raintheory]

This is for installing a Digital (optical) output onto portable units.

The only units that these outputs are standard on are some high-end decks. No portables have this output built-in.

Evidently it also bypasses SCMS.

Edited February 4, 2007 by raintheory

[Sparda]

Very technical! I doubt it is worth it to go through all that. What is wrong with analogue...

[mdmania]

Wow that Jan Florian Wagner is quite an electronics wizard! He's got quite some nice projects on the go there. I wish I'd gone in that direction and feel confident about modding some stuff. He's probably got no time at all and it would cost way too much, but wouldn't it be nice if he added a S/PDIF output onto my Hi-MD home deck...

If anyone here is a crack at such advanced electronics on this board, I'd have a second MD-105FX deck ordered and sent over for optical out implementation. There might even be a business in it?! How many would like an stand-alone Hi-MD deck with optical out?! We could set up a foundation on the forum, the ones interested could deposit money via PayPal or something like that to the administrators account if there could be such a thing, then a massive order from Kaneda at PJ, dispatched to our expert techies of agreed trust and voila, the Hi-MD deck w/ optical out to the masses.

I don't know why Sony just won't put out a Hi-MD deck with everything on it. So things would be much easier for every MD user. But that is so expected of Sony though, they are always complicated. There was a mod that I was able to follow easier in the past and that was adding out put to my JE440 digital output. It was challenging and one of my first modification I have ever done. I think adding digital output to a portable seems to be more complicated. I would say adding to MD-105FX wouldn't be as complicated in my own opinion. Just a matter of finding and understanding the internal board of the unit.

Edited February 6, 2007 by mdmania

[poe]

I would gladly pay up to $100 to have this done to one of my units. Could you imagine a RH1 or RH10 with a optical output? Wow! POE.

[mdmania]

I would gladly pay up to $100 to have this done to one of my units. Could you imagine a RH1 or RH10 with a optical output? Wow! POE.

Actually Optical output is not as relevant anymore, because RH1 can be uploaded to PC or Mac. I mean it would be nice to have an optical output but is not as necessary or as important anymore. But yeah, I would probably pay for an optical output.

Edited February 7, 2007 by mdmania

[Jamesy]

Sorry to drag up an old thread... But I'm happy to modify MD decks for optical output, I'd rather not bother with portables though - that's a clever mod the guy did but he can't put it back together!

Based in Edinburgh, UK - give me an email or PM if interested.

[Positronium]

Sorry to drag up an old thread too, but I'm trying to modify my SONY MZ-N505 and I can't find the needed chip on the player. Do someone know which one it is, and how to make that modification on the N505 ?

It would be great

I've been looking for something like that for many years, I hope it works.

Is it the only way to have a digital output on a portable player ? USB doesn't work ?

Thank you.

[sfbp]

I got an even easier idea..... make a switch of some kind that allows minimum wires to come out of the HiMD unit, instead of the DOUT on my MD deck, the DOUT as explained on an NH700.

Now the optical out socket, drivers, everything is already on the MD deck, just the signal is coming from HiMD - so in essence a HiMD Deck.

There are some minor problems like power supply for the HiMD and the physical arrangement won't be as nice as a deck, but for PLAYBACK (record is no problem) this should work nicely.

Anyone want to correspond on how to attack this one? I checked the schematics and the line goes more or less straight from the master chip to the optical out socket on the MD deck.

[digitaka]

Anyone tried this modification with a Sony MZ-NF810?

Actually, I'd be interested to hear if anyone has tried it with any portable MD and how well it works.

[sfbp]

Starting to look at the schematics for the NH700. Seems there is only one candidate for the output data and it is not connected to anything, namely pin 298 on IC801 (the monster main IC). It is labeled DADT (Audio Data Output Terminal. Not used). On the NF810 it looks like it's pin 50 (also DADT). Furthermore I note that in the R90/91 the comparable pin is brought out to a test point. Too much to hope that there is data there.....?

Comments?

[sfbp]

Well after half an hour on the phone to my friend (who may still come over), the big problem is likely to be the pins on the main DSP chip which has that output on it. The surface mount chip has lots of pins, and typically the unused ones are completely inaccessible.

So unless that pin actually goes through the circuit board (and there seems to be no reason that it should) we're out of luck. We will probably have a look though.

On the model that started this thread:

a. the main chip doesn't have its own analog out (which the NHx00 series appears to have)

b. the D->A (and incidentally A->D) is on a separate chip, and it was those pins he connected to, since the DADT output is brought to there, and they are reasonably accessible

So there's hope, but it's pretty faint at this point. So anyone with schematics and an Onkyo deck can tell us if they can find the same pin and whether it is accessible. I'll update this thread if I get anywhere, but I'm not holding my breath.

I'm not particularly interested in practising on a NetMD unit, since I can put NetMD disks in a deck and play them back using optical out. My interest here is to make a pseudo-deck which plays back HiMD into Optical.

[sfbp]

Bump... is noone interested at all?

Eureka! Digital out on the RH1 looks possible. There is a connecting point plumbed into the right pin (#258 in this case) which should allow connection to the raw data stream.

That's not to rule out the first generation units, but this does look promising.

In the schematic it seems Sony's convention is that if there is a connectable wire to pin 258 of IC 801 (forget about the 01 part), it will be numbered CL8258. Presumably a Connecting Link (?Connecting Land?) for pin 47 on IC 501 would be (hypothetically speaking) CL5047. And so on.

Stephen

[sfbp]

Continuing this (!) solo "sub-thread" it seems entirely likely (and logical) that the earlier units in fact have a Connecting Land (CL) for the DOUT (or DADT) pin. I can even guess which one it is on the RH910 (presumably same as the other 2nd gen units), a lot harder on 600/700/900 (all 3 of these use the same chip).

Does some genius know how to set up a test that will reliably and safely find that connection point without soldering it, or blowing anything up?

[sfbp]

(Still talking to myself - can't believe no one is interested!)

Here's the status:

3rd Generation (RH1), pin identified as well as connecting point (schematic numbers both).

2nd Generation (RH910, RH10), pin identified (numbered) connecting point down to 1 of 2 guesses. Slight problem, I don't have either model currently.

1st Generation (NHx00, X=6,7,F8,9) pin tentatively identified (pattern recognition), connecting point unknown but once again one of 2 or at most 3 places.

With that, all that is needed is a couple of wires to an optical transmit circuit (never mind the SCMS defeating for now) such as already exists in many decks.

I figure there are lots of ways to identify it, maybe by scope, or perhaps simply touching the wire to the right spot. The biggest barrier to concrete action right now is getting the RH1 open without busting it (which I failed to achieve last time around).

Stephen

added: Also I would be curious to know what it takes to turn a receiver into a transmitter and thus make the white 3.5mm socket into an output jack

[Giant_Rick]

It's a very interesting thread, I follow it avidously.. the problem, for me, is that it is a tricky operation and I'm afraid of damaging my MDs.

I'd try this on a NetMD (perhaps my N505) or a 'cheap' MD, never on a Hi-MD. Why? First any Hi-MD cost a lot and I don't want to waste my money on a recorder I'm going to damage, second they can upload to PC, which is better than opt. out.

If you are using an opt. out, why are you oing this? What are your aims?

[Avrin]

The DAC in an external receiver may theoretically be better than that in a portable unit. But this in not always the case, since portable minidisc units are traditionally equipped with really good hardware. So you need an exceptionally good external DAC to make it worth the effort.

Edited January 7, 2010 by Avrin

[sfbp]

It's a very interesting thread, I follow it avidously.. the problem, for me, is that it is a tricky operation and I'm afraid of damaging my MDs.

I'd try this on a NetMD (perhaps my N505) or a 'cheap' MD, never on a Hi-MD. Why? First any Hi-MD cost a lot and I don't want to waste my money on a recorder I'm going to damage, second they can upload to PC, which is better than opt. out.

If you are using an opt. out, why are you oing this? What are your aims?

I have 3 decks, that will play NetMD. They all have optical out. So for me is not an issue, I can play any one of them into the digital input of my wonderful Onkyo receiver.

However, imagine a HiMD disk that I made which is not uploadable, it can only be played back with the analog output. If I want to recover that music (and I recently got an email from a board user asking how) without losing too much quality, I am better off with the optical output to PC where I can record the wave file. So it's partly a capability thing.

In addition, I would just like to be able to listen to HiMD disks on the stereo. Example: I have a 1GB disk with 16.5 hours of opera (LP2). Some of these operas are more than 163 minutes long (capacity of 80m disk), but I can get the whole thing onto a single disk at LP2 by using HiMD because of its greater capacity, either to an 80m disk (capacity 4hr 50m) or a 1GB disk (capacity 16hr 30m). So it's a convenience thing, too.

What I would like is to put one HiMD unit and have it as a pseudo-deck hooked up more or less permanently to my stereo. I tried this with analog out, the result is not exciting.

Also I am currently discouraged from using HiMD for any sort of long term storage despite all the evidence that the data on there is probably safer than on a CD, particularly if you don't try to record more on a particular disk thereby subjecting it to the excesses of Sonic Stage. I also have faith that someone will eventually break the encryption (or Sony will simply release it) on HiMD, but until then I would like a way out if my hard disk crashes unexpectedly, and so that I don't have to keep so much music on the PC when I have plenty of storage on MD available.

Sure, an Onkyo HiMD deck would be nice, but currently I cannot afford one. To turn one of my HiMD units to be an output, even if it means losing some function (perhaps I won't be able to reassemble it, as one poster in this thread pointed out) seems a very small price to pay.

The DAC in an external receiver may theoretically be better than that in a portable unit. But this in not always the case, since portable minidisc units are traditionally equipped with really good hardware. So you need an exceptionally good external DAC to make it worth the effort.

I promise, Avrin, the DAC in my Onkyo TX-SR605 is amazing. Recordings played on the MDS-JE640 which sounded dreadful with the analog out (that is relatively a cheaper deck with no Type-S) sound wonderful via optical. This is exactly what I would have expected, although I didn't expect it because I didn't think of it until after I got the receiver.

As mentioned in reply to Giant_Rick, I tried the analog out (from HiMD) into the stereo before, and was underwhelmed. Maybe I'll double check, but my conclusion at the time was that line out on the HiMD portables was not optimized for "real" systems. Sure, headphones sound fantastic, but not the stereo. My 37-year old KEF Chorales can tell the difference

[sfbp]

Hehe, I think I may have found DOUT on the Second and First generation HiMD's (and earlier portables too, it's just as mentioned, I don't actually care about those). This means that the circuit linked to by OP is not even necessary. We shall see.....

[paperclip]

I find this interesting. A hack on a used portable @ $50 (used 600D) putting a digital out to a good dac = $1000 MD-133? Who knows.

You can easily find your digital out with a 'scope. Should be a fairly nice square wave when idle.

[sfbp]

I sorta gave up on this when I found I could just hook the USB to my HTPC and play it with SonicStage.

And the first generation HiMD's are way more impenetrable in terms of the circuit diagrams. At that point I ran into the seemingly inevitable RH910 problems that everyone else has been having (with laser power) and I ran out of steam on the project.

PS don't forget the convenience factor. The 600D does not allow power supply or battery sidecar, and unlike the 910 will not CHARGE at all through the USB.

[sfbp]

The original link is to a web page which is gone, however it's available here

http://web.archive.org/web/20071224163336/http://users.tkk.fi/~jwagner/electr/minidisc-spdif/

I tried editing the first post in this thread but it's not possible because the formatting of posts has changed internally since the board conversion.

Stephen